CN202122393U

CN202122393U - Electric blanket and low-voltage constant-temperature control device thereof

Info

Publication number: CN202122393U
Application number: CN2011202123281U
Authority: CN
Inventors: 胡少邦
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-06-22
Filing date: 2011-06-22
Publication date: 2012-01-25
Anticipated expiration: 2021-06-22

Abstract

The utility model belongs to the field of temperature control, and provides an electric blanket and a low-voltage constant-temperature control device thereof. By the aid of the low-voltage constant-temperature control device consisting of a high-voltage rectifying and filtering unit, a power conversion unit, a low-voltage rectifying and filtering unit, a voltage sampling unit, a temperature sampling unit, a security unit, a temperature regulating and equalizing unit, a signal feedback unit, an open-loop protection unit and a pulse-width modulation unit, low-voltage direct-current heating to an electric heating wire is realized, the output voltage value can be regulated automatically according to the preset temperature value and the temperature status of the electric heating wire, and the temperature of the electric heating wire can reach the preset temperature value within a short time and can be kept constant in high precision. Further, the low-voltage constant-temperature control device cannot be out of control due to failure or damage of some elements, and accordingly problems of poor constancy of temperature, high cost, low safety and possibility of generating electromagnetic radiation in the prior art are solved.

Description

A kind of electric blanket and low pressure constant temperature control device thereof

Technical field

The utility model belongs to domain of control temperature, relates in particular to a kind of electric blanket and low pressure constant temperature control device thereof.

Background technology

In the winter of weather cold, electric blanket is able to extensive use as a kind of warming tool.The control circuit of electric blanket product in the past generally adopts High Level AC Voltage directly heating wire to be heated; And the user is when using electric blanket; Health and electric blanket close contact; So there is serious electric shock hidden danger in this type of electric blanket, high-voltage alternating electrical heating meeting produces electromagnetic radiation in addition, and the electromagnetic radiation meeting produces injury to user's health.

The existing shortcoming of electric blanket to the electrical heating of above-mentioned employing high-voltage alternating; Prior art heats heating wire after adopting a low-tension supply feeding mechanism to convert High Level AC Voltage to low-voltage DC; And when temperature is higher than the temperature upper limit that is provided with in advance, close heating through switching tube of control circuit control, when temperature is lower than the lowest temperature value that is provided with in advance, open the mode of heating and carry out temperature control, there is serious potential safety hazard in this temperature control method; Switching tube has become a fatal key element; When this switching tube failed because, electric blanket will be in the long-time heating state, cause the high temperature fire easily.In addition; The heated at constant temperature mode that this prior art adopted can not be exported one continuously makes the heating wire temperature keep constant magnitude of voltage; The situation that the temperature of heating wire can occur fluctuating up and down during constant temperature, temperature constant property is poor, moreover; Adopt the low-tension supply feeding mechanism that the cost of the control circuit of whole electric blanket is increased.Therefore, prior art exists that temperature constant property is poor, cost is high, the low problem of security.

The utility model content

The purpose of the utility model is to provide a kind of low pressure constant temperature control device, is intended to solve that the temperature constant property that prior art exists is poor, cost high, the low problem of security.

The utility model is achieved in that a kind of low pressure constant temperature control device, and external AC power supply and heating wire is characterized in that, said low pressure constant temperature control device comprises:

The output of the said AC power of input termination carries out rectifying and wave-filtering to the high-voltage alternating signal of telecommunication from said AC power, and the high-voltage rectifying filter unit of the output HVDC signal of telecommunication;

Voltage input end connects the output of said high-voltage rectifying filter unit, the HVDC signal of telecommunication of said high-voltage rectifying filter unit output is transformed to the power converter unit of the low-voltage alternating-current signal of telecommunication;

The output of the said power converter unit of input termination; The said heating wire of output termination; The low-voltage alternating-current signal of telecommunication from said power converter unit is carried out exporting the low-voltage direct signal of telecommunication behind the rectifying and wave-filtering, the lower pressure rectifier filter unit of operating voltage is provided for said heating wire;

Import the output of the said lower pressure rectifier filter unit of termination, the voltage sampling unit of output after the low-voltage DC voltage of signals of said lower pressure rectifier filter unit output is taken a sample;

The temperature-sensitive end is responded to the variations in temperature of said heating wire, produces corresponding temperature-sensitive voltage according to the variations in temperature of said heating wire, and to the take a sample temperature sampling unit of back output of said temperature-sensitive voltage;

First detects the output of the said voltage sampling of termination unit; Second detects the output of the said temperature sampling unit of termination; When the output voltage of said lower pressure rectifier filter unit surpasses 36V or said temperature-sensitive electric voltage exception, generate the also Security Unit of output safety protection control signal;

The temperature-sensitive voltage input end connects the output of said temperature sampling unit, according to the temperature-sensitive voltage of said temperature sampling circuit output and the temperature-adjusting constant temperature unit of predefined temperature value generation temperature control signals;

The output of input termination said lower pressure rectifier filter unit is limited to 36V with interior pressure limiting unit with the output voltage of said lower pressure rectifier filter unit;

The safety protection control signal input part connects the output of said Security Unit; The output of the said temperature-adjusting constant temperature of temperature control signals input termination unit; The pressure limiting signal input part connects the output of said pressure limiting unit; Be used for the safety protection control signal to said Security Unit generation, the pressure limiting signal that temperature control signals that the temperature-adjusting constant temperature unit generates and pressure limiting unit generate feeds back the signal feedback unit of output;

Second output of the said signal feedback of control termination unit when said signal feedback unit does not have feedback signal output for a long time, generates and exports the open loop protected location of open loop protection control signal;

The control signal input is connected with first output of said signal feedback unit and the output of said open loop protected location simultaneously; Signal output part connects the control end of said power converter unit, and the control signal pulsewidth of regulating self output according to the open loop protection control signal of the control signal of said signal feedback unit output and the output of said open loop protected location is with the pwm unit of the duty of controlling said power converter unit;

The output of the said high-voltage rectifying filter unit of input termination; First output is connected with first voltage input end of said pwm unit and the voltage input end of said open loop protected location simultaneously; Second voltage input end of the second output termination said pwm unit provides first voltage regulation unit of operating voltage for said pwm unit and said open loop protected location;

The output of the said lower pressure rectifier filter unit of input termination; Output is connected with the driving voltage input of the voltage input end of said temperature sampling unit, said Security Unit and the driving voltage input of said temperature-adjusting constant temperature unit simultaneously, and second voltage regulation unit of operating voltage is provided for said Security Unit and said temperature-adjusting constant temperature unit.

Another purpose of the utility model is to provide a kind of electric blanket that comprises said low pressure constant temperature control device.

In the utility model; Through in said low pressure constant temperature control device, adopting said high-voltage rectifying filter unit, said power converter unit, said lower pressure rectifier filter unit, said voltage sampling unit, said temperature sampling unit, said Security Unit, said temperature-adjusting constant temperature unit, said signal feedback unit, said open loop protected location and said pwm unit; Realized said heating wire is carried out the low-voltage direct heating and can adjust output voltage values automatically according to the state of temperature of predefined temperature value and said heating wire; Make the temperature of said heating wire reach predefined temperature value fast and keep pinpoint accuracy constant; And said low pressure constant temperature control device does not occur out of controlly because of the inefficacy of some element and damage, has solved that existing in prior technology temperature constant property is poor, cost high, security is low and can produce the problem of electromagnetic radiation.

Description of drawings

Fig. 1 is the module map of the low pressure constant temperature control device that provides of the utility model embodiment;

Fig. 2 is the exemplary circuit figure of the low pressure constant temperature control device that provides of the utility model embodiment one;

Fig. 3 is the exemplary circuit figure of the low pressure constant temperature control device that provides of the utility model embodiment two;

Fig. 4 is the exemplary circuit figure of the low pressure constant temperature control device that provides of the utility model embodiment three.

The specific embodiment

For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

Fig. 1 shows the modular structure of the low pressure constant temperature control device that the utility model embodiment provides, and for the ease of explanation, only shows the part relevant with the utility model embodiment, and details are as follows:

Low pressure constant temperature control device 100 comprises:

High-voltage rectifying filter unit 101, the output of its input termination AC power 200 is used for the high-voltage alternating signal of telecommunication from AC power 200 is carried out rectifying and wave-filtering, and the output HVDC signal of telecommunication;

Power converter unit 102, its voltage input end connects the output of high-voltage rectifying filter unit 101, is used for the HVDC signal of telecommunication of high-voltage rectifying filter unit 101 outputs is transformed to the low-voltage alternating-current signal of telecommunication;

Lower pressure rectifier filter unit 103; The output of its input termination power converter unit 102; First end of output termination heating wire 300 is used for the low-voltage alternating-current signal of telecommunication from power converter unit 102 is carried out exporting the low-voltage direct signal of telecommunication behind the rectifying and wave-filtering, for heating wire 300 provides operating voltage;

Voltage sampling unit 104, the output of its input termination lower pressure rectifier filter unit 103 is used for the back output of taking a sample of the low-voltage DC voltage of signals of lower pressure rectifier filter unit 103 outputs;

Temperature sampling unit 105, its temperature-sensitive end is responded to the variations in temperature of said heating wire, produces corresponding temperature-sensitive voltage according to the temperature of heating wire 300, and to the output of taking a sample of temperature-sensitive voltage;

Security Unit 106; The output of its first detection termination voltage sampling unit 104; The output of the second test side jointing temp sampling unit 105 when the output voltage of lower pressure rectifier filter unit 103 surpasses 36V or temperature-sensitive electric voltage exception, generates and output safety protection control signal;

Temperature-adjusting constant temperature unit 107, the output of its temperature-sensitive voltage input end jointing temp sampling unit 105 generates temperature control signals according to the temperature-sensitive voltage of temperature sampling unit 105 outputs and the temperature value that is provided with in advance;

Pressure limiting unit 108, the output of its input termination lower pressure rectifier filter unit 103 is used for the output voltage of said lower pressure rectifier filter unit is limited in the 36V;

Signal feedback unit 109; Its safety protection control signal input part connects the output of Security Unit 106; The output of temperature control signals input termination temperature-adjusting constant temperature unit 107; The pressure limiting signal input part connects the output of pressure limiting unit 108, is used for the safety protection control signal to Security Unit 106 generations, and the pressure limiting signal that temperature control signals that temperature-adjusting constant temperature unit 107 generates and pressure limiting unit 108 generate feeds back output;

Open loop protected location 110, second output of its control termination signal feedback unit 109, when signal feedback unit 109 long-time no feedback signals are exported, the open loop protection control signal that generates and export;

Pwm unit 111; Its control signal input is connected with first output of signal feedback unit 108 and the output of open loop protected location 110 simultaneously; Signal output part connects the control end of power converter unit 102, protects the duty of the control signal pulsewidth of control signal adjusting self output with control power converter unit 102 according to the control signal of signal feedback unit 109 outputs and the open loop of open loop protected location 110 outputs;

First voltage regulation unit 112; The output of its input termination high-voltage rectifying filter unit 101; First output is connected with first voltage input end of pwm unit 111 and the voltage input end of open loop protected location 110 simultaneously; Second voltage input end of the second output termination pwm unit 111 is for pwm unit 111 and open loop protected location 110 provide operating voltage;

Second voltage regulation unit 113; The output of its input termination lower pressure rectifier filter unit 103; Output is connected with the voltage input end of temperature sampling unit 105, the driving voltage input of Security Unit 106 and the driving voltage input of temperature control signals temperature-adjusting constant temperature unit 107 simultaneously, for Security Unit 106 and temperature-adjusting constant temperature unit 107 provide operating voltage.

In the utility model; Through in low pressure constant temperature control device 100, adopting high-voltage rectifying filter unit 101, power converter unit 102, lower pressure rectifier filter unit 103, voltage sampling unit 104, temperature sampling unit 105, Security Unit 106, temperature-adjusting constant temperature unit 107, signal feedback unit 109, open loop protected location 110 and pwm unit 111; Realized heating wire 300 is carried out the low-voltage direct heating and can adjust output voltage values automatically according to the state of temperature of predefined temperature value and heating wire 300; Make the temperature of heating wire 300 reach the temperature value that is provided with in advance fast and keep pinpoint accuracy constant; And low pressure constant temperature control device 100 does not occur out of controlly because of the inefficacy of some element and damage, and existing in prior technology temperature constant property is poor, cost high, security is low and can produce the problem of electromagnetic radiation thereby solved.

Be described in detail below in conjunction with the concrete realization of specific embodiment the utility model:

Embodiment one:

Fig. 2 shows the exemplary circuit structure of the low pressure constant temperature control device that the utility model embodiment one provides, and for the ease of explanation, only shows the part relevant with the utility model embodiment one, and details are as follows:

As the utility model one embodiment; High-voltage rectifying filter unit 101 comprises rectifier bridge BD1 and electrochemical capacitor C1; The input of rectifier bridge BD1 is the input of high-voltage rectifying filter unit 101, and the positive voltage output end of rectifier bridge BD1 is the output of high-voltage rectifying filter unit 101, the negative voltage output termination first power supply ground of rectifier bridge BD1; The positive pole of electrochemical capacitor C1 connects the output of rectifier bridge BD1, and the negative pole of electrochemical capacitor C1 connects the first power supply ground.

As the utility model one embodiment; Power converter unit 102 comprises capacitor C 2, resistance R 1, diode D1, transformer T1, switching tube Q1 and resistance R 2; First end 1 of the primary coil of transformer T1 is the voltage input end of power converter unit 102; The anode of diode D1 is connected with first end 1 of resistance R 1 with the primary coil of transformer T1 through the capacitor C 2 of parallel connection; First end 3 of the secondary coil of transformer T1 is the output of power converter unit 102, and second end 4 of the secondary coil of transformer T1 connects second source ground, negative electrode while and second end 2 of the primary coil of transformer T1 and the input of switching tube Q1 of diode D1; The output of the control end of switching tube Q1 and switching tube Q1 constitutes the control end of power converter unit 102; Resistance R 2 is connected between the output and the first power supply ground of switching tube Q1, and switching tube Q1 is a N type metal-oxide-semiconductor, and its control end, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

As the utility model one embodiment; Lower pressure rectifier filter unit 103 comprises diode D2 and electrochemical capacitor C3; The anode of diode D2 is the input of lower pressure rectifier filter unit 103; The negative electrode of diode D2 is the output of lower pressure rectifier filter unit 103, and electrochemical capacitor C3 is connected between the negative electrode and second source ground of diode D2.

As the utility model one embodiment; Voltage sampling unit 104 comprises resistance R 2 and resistance R 3; First end of resistance R 2 is the input of voltage sampling unit 104; Second end of resistance R 2 is the output of voltage sampling unit 104, and resistance R 3 is connected between second end and second source ground of resistance R 2.

As the utility model one embodiment; Temperature sampling unit 105 comprises temperature-sensitive silk S1 and resistance R 4; Temperature-sensitive silk S1 is the temperature-sensitive end of temperature sampling unit 105, the first termination second source ground of temperature-sensitive silk S1, and first end of resistance R 4 is the output of temperature sampling unit 105; Second end of the first termination temperature-sensitive silk S1 of resistance R 4, second end of resistance R 4 is the voltage input end of temperature sampling unit 105.

As the utility model one embodiment; Security Unit 106 comprises operational amplifier U1, diode D3, resistance R 5, resistance R 6, diode D7 and diode D8; The in-phase input end of operational amplifier U1 is connected with the negative electrode of diode D7 and the negative electrode of diode D8 simultaneously, and the anode of diode D7 is first test side of Security Unit 106, and the anode of diode D8 is second test side of Security Unit 106; The output of operational amplifier U1 is the output of Security Unit 106; First end of the positive power source terminal connecting resistance R5 of operational amplifier U1, the negative supply termination second source ground of operational amplifier U1, the anode of diode D3 connects the output of operational amplifier U1; The negative electrode of diode D3 connects the in-phase input end of operational amplifier U1; First end of resistance R 5 is the driving voltage input of Security Unit 106, the inverting input of the second termination operational amplifier U1 of resistance R 5, and resistance R 6 is connected between second end and second source ground of resistance R 5.

As the utility model one embodiment; Temperature-adjusting constant temperature unit 107 comprises operational amplifier U2, resistance R 7, resistance R 8, adjustable resistance VR1, resistance R 9; The in-phase input end of operational amplifier U1 is the temperature-sensitive voltage input end of temperature-adjusting constant temperature unit 107; The output of operational amplifier U2 is the output of temperature-adjusting constant temperature unit 107, first end of the positive power source terminal connecting resistance R8 of operational amplifier U2, the negative supply termination second source ground of operational amplifier U2; Resistance R 7 is connected between the output and inverting input of operational amplifier U2; First end of resistance R 8 is the driving voltage input of temperature-adjusting constant temperature unit 107, and second end of resistance R 8 is connected with the inverting input of operational amplifier U2 and first end of adjustable resistance VR1 simultaneously, and resistance R 9 is connected between second end and second source ground of adjustable resistance VR1.

As the utility model one embodiment, pressure limiting unit 108 is a Zener diode ZD5, and the negative electrode of Zener diode ZD5 is the input of pressure limiting unit 108, and the anode of Zener diode ZD5 is the output of pressure limiting unit 108.

As the utility model one embodiment; Signal feedback unit 109 comprises diode D4, diode D5, resistance R 10 and photoelectrical coupler IC1; The anode of diode D4 is the safety protection control signal input part of signal feedback unit 108; The anode of diode D5 be signal feedback unit 109 the temperature control signals input; First end of resistance R 10 is the pressure limiting signal input part of signal feedback unit 109, and first end of resistance R 10 is connected the anode of the second termination photoelectrical coupler IC1 interior light emitting diodes of resistance R 10 simultaneously with the negative electrode of diode D4 and the negative electrode of diode D5; The negative electrode of photoelectrical coupler IC1 interior light emitting diodes connects second source ground, and the collector and emitter of the inner phototriode of photoelectrical coupler IC1 is respectively first output and second output of signal feedback unit 109.

As the utility model one embodiment; Open loop protected location 110 comprises resistance R 11, resistance R 12, operational amplifier U3, resistance R 13, Zener diode ZD1, resistance R 14, electrochemical capacitor C4, triode Q2 and resistance R 15; The base stage of triode Q2 is the control end of open loop protected location 110; The base stage of triode Q2 is connected with the inverting input of operational amplifier U3, and the emitter stage of triode Q2 connects the first power supply ground, and resistance R 15 is connected between the base stage and emitter stage of triode Q2; Electrochemical capacitor C4 is connected between the collector and emitter of triode Q2; First end of resistance R 13 is the voltage input end of open loop protected location 110, the in-phase input end of the second termination operational amplifier U3 of resistance R 13, and resistance R 14 is connected between the inverting input of first end and operational amplifier U3 of resistance R 13; Negative electrode while and the in-phase input end of operational amplifier U3 and first end of resistance R 12 of Zener diode ZD1; The anode of Zener diode ZD1 connects the first power supply ground, and first end of resistance R 11 is the output of open loop protected location 110, and second end of resistance R 11 is connected with the output of operational amplifier U3 and second end of resistance R 12 simultaneously; First end of the positive power source terminal connecting resistance R13 of operational amplifier U3, the negative supply termination first power supply ground of operational amplifier U3.

As the utility model one embodiment; Pwm unit 111 comprises resistance R 16, resistance R 17, Zener diode ZD2, operational amplifier U4, resistance R 18, capacitor C 5, oscillating circuit OSC1, latch LK1, NAND gate NAND1 and driver DR1; First end of resistance R 16 is the control signal input of pwm unit 111; The negative electrode of Zener diode ZD2 is connected with second end of resistance R 16, first end of resistance R 17 and the inverting input of operational amplifier U4 simultaneously; The anode of Zener diode ZD2 is connected with ground with second end of resistance R 17 simultaneously; First end of the positive power source terminal connecting resistance R18 of operational amplifier U4, the negative supply termination first power supply ground of operational amplifier U4, first end of resistance R 18 is first voltage input end of pwm unit 111; The anodal of capacitor C 5 is connected with second end of resistance R 18 and the input of oscillating circuit OSC1 simultaneously; The negative pole of capacitor C 5 connects the first power supply ground, and the output of oscillating circuit OSC1 is connected with the S input of latch LK1 and the first input end of NAND gate NAND1 simultaneously, the output of the R input termination operational amplifier U4 of latch LK1; The reversed-phase output QB of latch LK1 connects second input of NAND gate NAND1; The in-phase output end Q sky of latch LK1 connects, and the input of the driver connected DR1 of output of NAND gate NAND1, the positive power source terminal of driver DR1 are second voltage input end of pwm unit 111; The in-phase input end of the output of driver DR1 and operational amplifier U4 constitutes the signal output part of pwm unit 111, the negative supply termination first power supply ground of driver DR1.

As the utility model one embodiment; First voltage regulation unit 112 comprises the ancillary coil of resistance R 19, electrochemical capacitor C6, Zener diode ZD3, resistance R 20, Zener diode ZD4, electrochemical capacitor C7, resistance R 21, diode D6 and transformer T1; First end of resistance R 19 is the input of first voltage regulation unit 112; Just very first output of first voltage regulation unit 112 of electrochemical capacitor C6; The negative electrode of Zener diode ZD3 is second output of first voltage regulation unit 112; Anodal while and the negative electrode of Zener diode ZD3 and first end of resistance R 20 of electrochemical capacitor C6; The negative pole of electrochemical capacitor C6 is connected with the first power supply ground with the anode of Zener diode ZD3 simultaneously, and the negative electrode of Zener diode ZD4 is connected with second end of resistance R 20 and the positive pole of electrochemical capacitor C7 simultaneously, and the anode of Zener diode ZD4 is connected with the first power supply ground with the negative pole of electrochemical capacitor C7 simultaneously; First end of resistance R 21 is connected with second end of resistance R 19 and the positive pole of electrochemical capacitor C7 simultaneously; Second end of the negative electrode connecting resistance R21 of diode D6, the anode of diode D6 connect first end 5 of the secondary coil of transformer T1, and it is the first power supply ground that second end 6 of the secondary coil of transformer T1 connects.

As the utility model one embodiment; Second voltage regulation unit 113 comprises triode Q3, resistance R 22, Zener diode ZD6 and electrochemical capacitor C8; The current collection of triode Q3 is the input of second voltage regulation unit 113 very; The emission of triode Q3 is the output of second voltage regulation unit 113 very; Resistance R 22 is connected between the negative electrode of colelctor electrode and Zener diode ZD6 of triode Q3, and the anode of Zener diode ZD6 is connected with negative pole and the second source ground of electrochemical capacitor C8 simultaneously, and the positive pole of electrochemical capacitor C8 connects the emitter stage of triode Q3.

Low pressure constant temperature control device 100 also comprises resistance R 65, and resistance R 65 is connected between the control end of output and switching tube Q1 of driver DR1.

The operation principle of the low pressure constant temperature control device that present embodiment provided is:

High Level AC Voltage gets into high-voltage rectifying filter unit 101 by AC power 200; Through rectifier bridge BD1 High Level AC Voltage is carried out the high voltage direct current that rectification output is mingled with ripple current and interfering signal, carry out exporting high voltage direct current stably after the filtering through capacitor C 1 subsequently; High voltage direct current gets into first voltage regulation unit 112 and power converter unit 102 through the parallel circuit that resistance R 19 and capacitor C 2 and resistance R 1 are formed respectively stably; First voltage regulation unit 112 carries out dividing potential drop through the high voltage direct current of 19 pairs of inputs of resistance R; Undertaken behind the voltage regulation filtering to the driver DR1 of pwm unit 111 provides operating voltage by Zener diode ZD4 and electrochemical capacitor C7, undertaken behind the voltage regulation filtering driving voltage being provided for other elements of pwm unit 111 and open loop protected location 109 by resistance R 20 dividing potential drops, Zener diode ZD3 and electrochemical capacitor C6.

Power converter unit 102 is a single-ended flyback power inverter; The high voltage direct current of input converts thereof into low-voltage AC by switching tube Q1 driving transformer T1 and exports lower pressure rectifier filter unit 103 to; Capacitor C 2, resistance R 1 and D1 form clamp circuit, are used to suppress the peak voltage that switching tube Q1 shutdown moment produces, and resistance R 6 is a current sampling resistor; For comparator U4 in-phase end provides the feedback voltage sequential, be used for simultaneously switching tube Q1 is carried out overcurrent protection.

Lower pressure rectifier filter unit 103 carries out for heating wire 300 low-voltage DC being provided behind the rectifying and wave-filtering to low-voltage AC through diode D2 and electrochemical capacitor C3.

Voltage sampling unit 104 is through the resistance R 2 and the low-voltage DC of 3 pairs of lower pressure rectifier filter units of resistance R, the 103 outputs dividing potential drop of connecting, and the partial pressure value on the resistance R 3 gets into Security Unit 106 as the output signal through diode D7.

Temperature sampling unit 105 through resistance R 4 and temperature-sensitive silk S1 to the second voltage regulation unit voltage dividing potential drop of connecting; When the partial pressure value on the temperature-sensitive silk S1 gets into temperature-adjusting constant temperature unit 107 as the output signal; It gets into Security Unit 106 through diode D8; Its resistance value can change with heating wire 300 variation of temperature during temperature-sensitive silk S1 induced electricity heated filament 300 temperature, so its partial pressure value also can change with variation of temperature.

Second voltage regulation unit 113 is that Security Unit 106 and temperature-adjusting constant temperature unit 107 provide operating voltage through the mu balanced circuit that triode Q3, resistance R 22, Zener diode ZD6 and electrochemical capacitor C8 form.

In Security Unit 106; The operating voltage that is provided by second voltage regulation unit 113 is carried out after the dividing potential drop reference voltage as operational amplifier U1 inverting input through resistance R 5 and resistance R 6; When the voltage of lower pressure rectifier filter unit 103 output surpasses 36V or diode D2 can not rectification the time; The reference voltage of operational amplifier U1 inverting input will be less than the voltage of its in-phase input end; Operational amplifier U1 output this moment high level, this high level is as the first output entering pwm unit 111 of safety protection control signal through pulse-modulated signal feedback unit 108; In like manner; When temperature-sensitive silk S1 senses heating wire 300 temperature and is higher than maximum temperature capping value or temperature-sensitive silk S1 and heating wire 300 when being short-circuited; The reference voltage of operational amplifier U1 inverting input will be less than the voltage of its in-phase input end; Operational amplifier U1 output this moment high level, this high level is as the first output entering pwm unit 111 of safety protection control signal through pulse-modulated signal feedback unit 108; Diode D3 is used to lock operational amplifier U1 and keeps the high level output state, till fault eliminating and circuit reset;

The resistance R 8 of 107 inside, temperature-adjusting constant temperature unit; After adjustable resistance VR1, resistance R 9 series connection operating voltage of second voltage regulation unit, 113 outputs is carried out dividing potential drop; The dividing potential drop summation of adjustable resistance VR1 and resistance R 9 is as the inverting input of reference voltage input operational amplifier U2; Temperature sampling unit 105 output voltage signals of the reference voltage of operational amplifier U2 inverting input input and in-phase input end input carry out voltage error and relatively amplify, and the signal of telecommunication after will amplifying is as the first output entering pwm unit 111 of temperature control signals through signal feedback unit 109;

In open loop protected location 110; When low pressure constant temperature control device 100 operate as normal; Triode Q2 conducting, operational amplifier U3 exports high level, when low pressure constant temperature control device 100 open loop faults; The 108 no feedback signal outputs of signal feedback unit; Triode Q2 ends, and charged when electrochemical capacitor C4 voltage be higher than Zener diode ZD1 through resistance R 14 pair electrochemical capacitor C4s by the operating voltage of first voltage regulation unit, 112 inputs this moment, and operational amplifier U3 controls signal to pwm unit 111 through resistance R 11 output low levels as the open loop protection.

In the pwm unit 111, oscillating circuit OSC1 is that latch LK1 and NAND gate NAND1 provide benchmark oscillating impulse clock signal, and oscillating circuit OSC1 output frequency value is by the capacitance decision of the resistance and the capacitor C 5 of resistance R 18; Operational amplifier U4 compares output to the signal from in-phase input end and inverting input; The pulse sequence signal of a variation is provided for latch LK1; Resistance R 16 is the signal dividing potential drop damping resistance of pwm unit 111 inputs with resistance R 17; Zener diode ZD2 plays the pressure limiting effect to the inverting input of operational amplifier U4, and the partial pressure value maximum that is used to limit on the resistance R 6 can not surpass Zener diode ZD2 voltage stabilizing value, thereby the maximum that has limited switching tube Q1 is passed through current value; Latch LK1 latchs output according to the Different Logic sequential of R end and the input of S end; NAND gate NAND1 drives signal according to the input timing output pulse width of two inputs, again through 102 work of driver DR1 driving power converter unit.When pwm unit 111 receive by signal feedback unit 109 input from the safety protection control signal of Security Unit 106 time; This safety protection control signal gets into the inverting input of operational amplifier U4 through resistance R 16; And convert this safety protection control signal to pwm control signal and export driver DR1 to by the combinational circuit that latchs the pulsewidth modulation function that has that operational amplifier U4, latch LK1 and NAND gate NAND1 are constituted, driver DR1 exports pwm control signal to power converter unit 102; When pwm unit 111 receive by signal feedback unit 108 input from the temperature control signals of temperature-adjusting constant temperature unit 107 time, also adopt as safety protection control Signal Processing mode carried out temperature control signals handle the back by driver DR1 output pwm control signal; When low pressure constant temperature control device 100 open loop faults; Pwm unit 111 receives the open loop protection control signal from open loop protected location 110; Also adopt as safety protection control Signal Processing mode being carried out open loop protection control signal and handle the back by driver DR1 output pwm control signal; Switching tube Q1 in the power converter unit 102 receives from the pwm control signal of driver DR1 through its control end and exports corresponding duty cycle pulse; Thereby the voltage transformation coefficient of control power converter unit 102 reaches the purpose of controlling output DC voltage.

In the present embodiment; In the utility model; Through in low pressure constant temperature control device 100, adopting high-voltage rectifying filter unit 101, power converter unit 102, lower pressure rectifier filter unit 103, voltage sampling unit 104, temperature sampling unit 105, Security Unit 106, temperature-adjusting constant temperature unit 107, signal feedback unit 109, open loop protected location 110 and pwm unit 111; Realized heating wire 300 is carried out the low-voltage direct heating and can adjust output voltage values automatically according to the state of temperature of predefined temperature value and heating wire 300; Make the temperature of heating wire 300 reach predefined temperature value fast and keep pinpoint accuracy constant; And low pressure constant temperature control device 100 does not occur out of controlly because of the inefficacy of some element and damage, and existing in prior technology temperature constant property is poor, cost high, security is low and can produce the problem of electromagnetic radiation thereby solved.

Embodiment two:

Fig. 3 shows the exemplary circuit structure of the low pressure constant temperature control device that the utility model embodiment two provides, and for the ease of explanation, only shows the part relevant with the utility model embodiment two, and details are as follows:

As the utility model one embodiment; High-voltage rectifying filter unit 101 comprises rectifier bridge BD11 and electrochemical capacitor C11; The input of rectifier bridge BD11 is the input of high-voltage rectifying filter unit 101, and the positive voltage output end of rectifier bridge BD11 is the output of high-voltage rectifying filter unit 101, the negative voltage output termination first power supply ground of rectifier bridge BD11; The positive pole of electrochemical capacitor C11 connects the output of rectifier bridge BD11, and the negative pole of electrochemical capacitor C11 connects the first power supply ground.

As the utility model one embodiment; Power converter unit 102 comprises switching tube Q11, switching tube Q12, transformer T11; The control end of the control end of switching tube Q11 and switching tube Q12 constitutes the control end of power converter unit 102; First end 1 of the primary coil of the input termination transformer T11 of switching tube Q11; Second end 2 of the primary coil of transformer T11 is the voltage input end of power converter unit 102; First end 4 of the secondary coil of transformer T11 and the 3rd end 6 are the output of power converter unit 102, and second end 5 of the secondary coil of transformer T11 connects second source ground, and the output of switching tube Q11 is connected with the first power supply ground with the output of switching tube Q12 simultaneously; The 3rd end 3 of the primary coil of the input termination transformer T11 of switching tube Q12; Switching tube Q11 and switching tube Q12 are N type metal-oxide-semiconductor, and the control end of switching tube Q11, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively, and the control end of switching tube Q12, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

As the utility model one embodiment; Lower pressure rectifier filter unit 103 comprises diode D11, diode D12, inductance L 1 and electrochemical capacitor C12; The anode of the anode of diode D11 and diode D12 is formed the input of lower pressure rectifier filter unit 103; The anode of diode D11 connects first end 4 of the secondary coil of transformer T11; The anode of diode D12 connects the 3rd end 6 of the secondary coil of transformer T11, and first end of inductance L 1 is connected with the negative electrode of diode D11 and the negative electrode of diode D12 simultaneously, and second end of inductance L 1 is the output of lower pressure rectifier filter unit 103; The positive pole of electrochemical capacitor C12 connects second end of inductance L 1, and the negative pole of electrochemical capacitor C12 connects second source ground.

As the utility model one embodiment; Voltage sampling unit 104 comprises resistance R 23 and resistance R 24; First end of resistance R 23 is the input of voltage sampling unit 104; Second end of resistance R 23 is the output of voltage sampling unit 104, and resistance R 24 is connected between second end and second source ground of resistance R 23.

As the utility model one embodiment; Temperature sampling unit 105 comprises temperature-sensitive silk S2 and resistance R 25; Temperature-sensitive silk S2 is the temperature-sensitive end of temperature sampling unit 105, the first termination second source ground of temperature-sensitive silk S2, and first end of resistance R 25 is the output of temperature sampling unit 105; Second end of the first termination temperature-sensitive silk S2 of resistance R 25, second end of resistance R 25 is the voltage input end of temperature sampling unit 105.

As the utility model one embodiment; Security Unit 106 comprises operational amplifier U11, diode D13, resistance R 26, resistance R 27, diode D16 and diode D17, and the in-phase input end of operational amplifier U11 is connected with the negative electrode of diode D16 and the negative electrode of diode D17 simultaneously, and the anode of diode D16 is first test side of Security Unit 106; The anode of diode D17 is second test side of Security Unit 106;, the output of operational amplifier U11 is the output of Security Unit 106, first end of the positive power source terminal connecting resistance R26 of operational amplifier U11; The negative supply termination second source ground of operational amplifier U11; The anode of diode D13 connects the output of operational amplifier U11, and the negative electrode of diode D13 connects the in-phase input end of operational amplifier U11, and first end of resistance R 26 is the driving voltage input of Security Unit 106; The inverting input of the second termination operational amplifier U11 of resistance R 26, resistance R 27 are connected between second end and second source ground of resistance R 26.

As the utility model one embodiment; Temperature-adjusting constant temperature unit 107 comprises operational amplifier U12, resistance R 28, resistance R 29, adjustable resistance VR2, resistance R 30; The in-phase input end of operational amplifier U12 is the temperature-sensitive voltage input end of temperature-adjusting constant temperature unit 107; The output of operational amplifier U12 is the output of temperature-adjusting constant temperature unit 107; First end of the positive power source terminal connecting resistance R29 of operational amplifier U12; The negative supply termination second source ground of operational amplifier U12, resistance R 28 is connected between the output and inverting input of operational amplifier U12, and first end of resistance R 29 is the driving voltage input of temperature-adjusting constant temperature unit 107; Second end of resistance R 29 is connected with the inverting input of operational amplifier U12 and first end of adjustable resistance VR2 simultaneously, and resistance R 30 is connected between second end and second source ground of adjustable resistance VR2.

As the utility model one embodiment, pressure limiting unit 108 is a Zener diode ZD14, and the negative electrode of Zener diode ZD14 is the input of pressure limiting unit 108, and the anode of Zener diode ZD14 is the output of pressure limiting unit 108.

As the utility model one embodiment; Signal feedback unit 109 comprises diode D14, diode D15, resistance R 31 and photoelectrical coupler IC2; The anode of diode D14 is the safety protection control signal input part of signal feedback unit 109; The anode of diode D15 be signal feedback unit 109 the temperature control signals input; First end of resistance R 31 is the pressure limiting signal input part of signal feedback unit 109, and first end of resistance R 31 is connected the anode of the second termination photoelectrical coupler IC2 interior light emitting diodes of resistance R 31 simultaneously with the negative electrode of diode D14 and the negative electrode of diode D15; The negative electrode of photoelectrical coupler IC2 interior light emitting diodes connects second source ground, and the collector and emitter of the inner phototriode of photoelectrical coupler IC2 is respectively first output and second output of signal feedback unit 109.

As the utility model one embodiment; Open loop protected location 110 comprises resistance R 32, resistance R 33, operational amplifier U13, resistance R 34, Zener diode ZD11, resistance R 35, electrochemical capacitor C13, triode Q13 and resistance R 36; The base stage of triode Q13 is the control end of open loop protected location 110; The base stage of triode Q13 is connected with the inverting input of operational amplifier U13, and the emitter stage of triode Q13 connects the first power supply ground, and resistance R 36 is connected between the base stage and emitter stage of triode Q13; Electrochemical capacitor C13 is connected between the collector and emitter of triode Q13; First end of resistance R 34 is the voltage input end of open loop protected location 110, the in-phase input end of the second termination operational amplifier U13 of resistance R 34, and resistance R 35 is connected between the inverting input of first end and operational amplifier U13 of resistance R 34; Negative electrode while and the in-phase input end of operational amplifier U13 and first end of resistance R 33 of Zener diode ZD11; The anode of Zener diode ZD11 connects the first power supply ground, and first end of resistance R 32 is the output of open loop protected location 110, and second end of resistance R 32 is connected with the output of operational amplifier U13 and second end of resistance R 33 simultaneously; First end of the positive power source terminal connecting resistance R34 of operational amplifier U13, the negative supply termination first power supply ground of operational amplifier U13.

As the utility model one embodiment; Pwm unit 111 comprises resistance R 37, capacitor C 14, oscillating circuit OSC2, operational amplifier U14, resistance R 38, resistance R 39, trigger TR1, latch LK2, NAND gate NAND2, NAND gate NAND3, driver DR2 and driver DR3; First end of resistance R 37 is first voltage input end of pwm unit 111; Second end of resistance R 37 is connected with the input of oscillating circuit OSC2, the positive pole of capacitor C 14 and the in-phase input end of operational amplifier U14 simultaneously; The negative pole of capacitor C 14 connects the first power supply ground; The output of oscillating circuit OSC2 is connected with the input of trigger TR1, the S input of latch LK2, second input of NAND gate NAND2 and second input of NAND gate NAND3 simultaneously, and first end of resistance R 38 is the control signal input of pwm unit 111, and second end of resistance R 38 is connected with the inverting input of operational amplifier U14 and first end of resistance R 39 simultaneously; Second termination, the first power supply ground of resistance R 39; The R input of the output termination latch LK2 of operational amplifier U14,, first end of the positive power source terminal connecting resistance R37 of operational amplifier U14; The negative supply termination first power supply ground of operational amplifier U14; The reversed-phase output QB of latch LK2 is connected with the 3rd input of NAND gate NAND2 and the 3rd input of NAND gate NAND3 simultaneously, and the in-phase output end Q sky of latch LK2 connects, and the reversed-phase output QB of trigger TR1 connects the first input end of NAND gate NAND2; The in-phase output end Q of trigger TR1 connects the first input end of NAND gate NAND3; The output of the input termination NAND gate NAND2 of driver DR2, the positive power source terminal of driver DR2 is second voltage input end of pwm unit 111, the output of the output of driver DR2 and driver DR3 constitutes the signal output part of pwm unit 111; The negative power end of driver DR2 is connected with the negative power end of driver DR3; The output of the input termination NAND gate NAND3 of driver DR3, the positive power source terminal of the driver connected DR2 of positive power source terminal of driver DR3, the negative supply termination first power supply ground of driver DR3.

As the utility model one embodiment; First voltage regulation unit 112 comprises the ancillary coil of resistance R 40, electrochemical capacitor C15, Zener diode ZD12, resistance R 41, Zener diode ZD13, electrochemical capacitor C16, resistance R 42, rectifier bridge BD12 and transformer T11; First end of resistance R 40 is the input of first voltage regulation unit 112; The negative electrode of Zener diode ZD12 is first output of first voltage regulation unit 112; The anodal of electrochemical capacitor C15 is connected with the negative electrode of Zener diode ZD12 and first end of resistance R 41 simultaneously; The negative pole of electrochemical capacitor C15 is connected with the first power supply ground with the anode of Zener diode ZD12 simultaneously; The negative electrode of Zener diode ZD13 is second output of first voltage regulation unit 112, and the negative electrode of Zener diode ZD13 is connected with second end of resistance R 41 and the positive pole of electrochemical capacitor C16 simultaneously, and the anode of Zener diode ZD13 is connected with the first power supply ground with the negative pole of electrochemical capacitor C16 simultaneously; First end of resistance R 42 is connected with second end of resistance R 40 and the positive pole of electrochemical capacitor C16 simultaneously; The positive voltage output end of the second termination rectifier bridge BD12 of resistance R 42, the first input end of rectifier bridge BD12 and second input are connected the negative voltage output termination first power supply ground of rectifier bridge BD12 with first end 7 of the ancillary coil of transformer T11 respectively with second end 8.

As the utility model one embodiment; Second voltage regulation unit 113 comprises triode Q14, resistance R 43, Zener diode ZD15 and electrochemical capacitor C17; The current collection of triode Q14 is the input of second voltage regulation unit 113 very; The emission of triode Q14 is the output of second voltage regulation unit 113 very; Resistance R 43 is connected between the negative electrode of colelctor electrode and Zener diode ZD15 of triode Q14, and the anode of Zener diode ZD15 is connected with negative pole and the second source ground of electrochemical capacitor C17 simultaneously, and the positive pole of electrochemical capacitor C17 connects the emitter stage of triode Q14.

Low pressure constant temperature control device 100 also comprises resistance R 66 and resistance R 67, and resistance R 66 is connected between the control end of output and switching tube Q11 of driver DR2, and resistance R 67 is connected between the control end of output and switching tube Q12 of driver DR3.

High Level AC Voltage gets into high-voltage rectifying filter unit 101 by AC power 200; Through rectifier bridge BD11 High Level AC Voltage is carried out the high voltage direct current that rectification output is mingled with ripple current and interfering signal, carry out exporting high voltage direct current stably after the filtering through capacitor C 11 subsequently; High voltage direct current passes through second end, 2 entering, first voltage regulation unit 112 and power converter unit 102 of the primary coil of resistance R 40 and transformer T11 respectively stably; First voltage regulation unit 112 carries out dividing potential drop through the high voltage direct current of 40 pairs of inputs of resistance R; Undertaken behind the voltage regulation filtering operating voltage being provided by Zener diode ZD13 and electrochemical capacitor C16, undertaken behind the voltage regulation filtering operating voltage being provided and reference voltage being provided for operational amplifier U14 for the oscillating circuit OSC2 of pwm unit 111 and open loop protected location 110 by resistance R 41 dividing potential drops, Zener diode ZD12 and electrochemical capacitor C15 for the driver DR2 of pwm unit 111 and driver DR3.

Power converter unit 102 is a push-pull type power inverter, converts the high voltage direct current of importing to low-voltage AC by switching tube Q11 and switching tube Q21 alternation switch task driven transformer T11 and exports lower pressure rectifier filter unit 103 to.

Lower pressure rectifier filter unit 103 carries out rectification through diode D11 and diode D12 to low-voltage AC, and is carried out for heating wire 300 low-voltage DC being provided after the filtering with electrochemical capacitor C12 by inductance L 1.

Voltage sampling unit 104 is through the resistance R 23 and the low-voltage DC of 24 pairs of lower pressure rectifier filter units of resistance R, the 103 outputs dividing potential drop of connecting, and the partial pressure value of first end of resistance R 24 gets into Security Unit 106 as the output signal through diode D16.

Temperature sampling unit 105 through resistance R 25 and temperature-sensitive silk S2 to the operating voltage that provides by second voltage regulation unit 113 dividing potential drop of connecting; When the partial pressure value on the temperature-sensitive silk S2 gets into temperature control signals generative circuit 107 as the output signal; It is through diode D17 entering Security Unit 106, and during the temperature of temperature-sensitive silk S2 induced electricity heated filament 300, its resistance value can change with the variations in temperature of heating wire 300; Therefore, the partial pressure value of temperature-sensitive silk S2 also can change with the variations in temperature of heating wire 300.

Second voltage regulation unit 113 is that Security Unit 106 and temperature-adjusting constant temperature unit 107 provide operating voltage through the mu balanced circuit of being made up of resistance R 43, triode Q14, Zener diode ZD15 and electrochemical capacitor C17.

In Security Unit 106; The operating voltage that is provided by second voltage regulation unit 113 is carried out after the dividing potential drop reference voltage as the inverting input of operational amplifier U11 through resistance R 26 and resistance R 27; When the voltage of lower pressure rectifier filter unit 103 output surpasses 36V or diode D11 or diode D12 can not rectification the time; The reference voltage of the inverting input of operational amplifier U11 will be less than the voltage of its in-phase input end; Operational amplifier U11 output this moment high level, this high level is as the first output entering pwm unit 111 of safety protection control signal through pulse-modulated signal feedback unit 109; In like manner; When the temperature of sensing heating wire 300 as temperature-sensitive silk S2 is higher than maximum temperature capping value or temperature-sensitive silk S2 and heating wire 300 when being short-circuited; The reference voltage of operational amplifier U11 inverting input will be less than the voltage of its in-phase input end; Operational amplifier U11 output this moment high level, this high level is as the first output entering pwm unit 111 of safety protection control signal through signal feedback unit 109; Diode D13 is used to lock operational amplifier U11 and keeps the high level output state, till fault eliminating and circuit reset.

The resistance R 29 of 107 inside, temperature-adjusting constant temperature unit; After adjustable resistance VR2, resistance R 30 series connection operating voltage of second voltage regulation unit, 113 outputs is carried out dividing potential drop; The dividing potential drop summation of adjustable resistance VR2 and resistance R 30 is as the inverting input of reference voltage input operational amplifier U12; Operational amplifier U12 carries out voltage error through the temperature-sensitive dc signal that the reference voltage and the in-phase input end of its inverting input input are imported and relatively amplifies, and the signal of telecommunication after will amplifying is as the first output entering pwm unit 111 of temperature control signals through signal feedback unit 109;

In open loop protected location 110; When low pressure constant temperature control device 100 operate as normal; Triode Q13 conducting, operational amplifier U13 exports high level, when low pressure constant temperature control device 100 open loop faults; The 109 no feedback signal outputs of signal feedback unit; Triode Q13 ends, and charged when electrochemical capacitor C13 voltage be higher than Zener diode ZD11 through resistance R 35 pair electrochemical capacitor C13s by the operating voltage of first voltage regulation unit, 112 inputs this moment, and operational amplifier U13 controls signal to pwm unit 111 through resistance R 32 output low levels as the open loop protection.

Oscillating circuit OSC2 is that latch LK2, trigger TR1, NAND gate NAND2 and NAND gate NAND3 provide benchmark oscillating impulse clock signal in the pwm unit 111, and the frequency values of the benchmark oscillating impulse clock signal of oscillating circuit OSC2 output is by the appearance value decision of the resistance and the capacitor C 14 of resistance R 37; Operational amplifier U14 compares output to the signal from its in-phase input end and inverting input; The pulse sequence signal of a variation is provided for latch LK2; Resistance R 38 is the signal dividing potential drop damping resistance of pwm unit 111 inputs with resistance R 39, and latch LK2 latchs output according to the Different Logic sequential of its R input and the input of S input; Trigger TR1 converts benchmark oscillating impulse clock signal to two the pulse sequence signals that replace each other from its in-phase output end Q and the output of reversed-phase output QB output; NAND gate NAND2 and NAND gate NAND3 drive signal according to the input timing output pulse width of three inputs, pass through the switching tube Q11 and the switching tube Q12 alternation of driver DR2 and driver DR3 driving power converter unit 102 again.When pwm unit 111 receive by signal feedback unit 109 input from the safety protection control signal of Security Unit 106 time; This safety protection control signal gets into the inverting input of operational amplifier U14 through resistance R 38; And convert this safety protection control signal to the two-way pwm control signal and export driver DR2 and driver DR3 respectively to by the combinational circuit that latchs the pulsewidth modulation function that has that operational amplifier U14, trigger TR1, latch LK2, NAND gate NAND2 and NAND gate NAND3 are constituted, driver DR2 and driver DR3 export the two-way pwm control signal to the control end of switching tube Q11 and the control end of switching tube Q12 respectively; When pwm unit 111 receive by signal feedback unit 109 input from the temperature control signals of temperature-adjusting constant temperature unit 107 time, also adopt as safety protection control Signal Processing mode carried out temperature control signals handle the back and export the two-way pwm control signal to the control end of switching tube Q11 and the control end of switching tube Q12 respectively by driver DR2 and driver DR3; When low pressure constant temperature control device 100 open loop faults; Pwm unit 111 receives the open loop protection control signal from open loop protected location 110; Also adopt as safety protection control Signal Processing mode is carried out open loop protection control signal processing back and export the two-way pwm control signal to the control end of switching tube Q11 and the control end of switching tube Q12 respectively by driver DR2 and driver DR3; Switching tube Q11 in the power converter unit 102 and the switching tube Q12 control end through separately receives from the two-way pwm control signal of driver DR2 and driver DR3 and exports corresponding duty cycle pulse; Thereby the voltage transformation coefficient of control power converter unit 102 reaches the purpose of controlling output DC voltage.

Embodiment three:

Fig. 4 shows the exemplary circuit structure of the low pressure constant temperature control device that the utility model embodiment three provides, and for the ease of explanation, only shows the part relevant with the utility model embodiment three, and details are as follows:

As the utility model one embodiment; High-voltage rectifying filter unit 101 comprises rectifier bridge BD21 and electrochemical capacitor C21; The input of rectifier bridge BD21 is the input of high-voltage rectifying filter unit 101, and the positive voltage output end of rectifier bridge BD21 is the output of high-voltage rectifying filter unit 101, and the negative voltage output of rectifier bridge BD21 is the first power supply ground; The positive pole of electrochemical capacitor C21 connects the output of rectifier bridge BD21, and the negative pole of electrochemical capacitor C21 connects the first power supply ground.

As the utility model one embodiment; Power converter unit 102 comprises switching tube Q21, switching tube Q22, diode D21, diode D22, capacitor C 22, capacitor C 23 and transformer T21; The control end of the control end of switching tube Q21 and switching tube Q22 constitutes the control end of power converter unit 102; The input of switching tube Q21 is the voltage input end of power converter unit 102; The input of switching tube Q22 is connected with first end 1 of the primary coil of the negative electrode of the anode of the output of switching tube Q21, diode D21, diode D22 and transformer T21 simultaneously; The output of switching tube Q22 is connected with the anode of diode D22, first end and the first power supply ground of capacitor C 22 simultaneously; The negative electrode of diode D21 is connected with the input of switching tube Q21 and first end of capacitor C 23 simultaneously; Second end while of capacitor C 23 is connected with second end 2 of the primary coil of transformer T21 and second end of capacitor C 22; First end 3 of the secondary coil of transformer T21 and the 3rd end 5 are the output of power converter unit 102, and second end 4 of the secondary coil of transformer T21 connects second source ground, and switching tube Q21 and switching tube Q22 are N type metal-oxide-semiconductor; The control end of switching tube Q21, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively, and the control end of switching tube Q22, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

As the utility model one embodiment; Lower pressure rectifier filter unit 103 comprises diode D21, diode D22, inductance L 2 and electrochemical capacitor C24; The anode of the anode of diode D21 and diode D22 is formed the input of lower pressure rectifier filter unit 103; The anode of diode D21 connects first end 3 of the secondary coil of transformer T21; The anode of diode D22 connects the 3rd end 5 of the secondary coil of transformer T21, and first end of inductance L 2 is connected with the negative electrode of diode D21 and the negative electrode of diode D22 simultaneously, and second end of inductance L 2 is the output of lower pressure rectifier filter unit 103; The positive pole of electrochemical capacitor C24 connects second end of inductance L 2, and the negative pole of electrochemical capacitor C24 connects second source ground.

As the utility model one embodiment; Voltage sampling unit 104 comprises resistance R 44 and resistance R 45; First end of resistance R 44 is the input of voltage sampling unit 104; Second end of resistance R 44 is the output of voltage sampling unit 104, and resistance R 45 is connected between second end and second source ground of resistance R 44.

As the utility model one embodiment; Temperature sampling unit 105 comprises temperature-sensitive silk S3 and resistance R 46; Temperature-sensitive silk S3 is the temperature-sensitive end of temperature sampling unit 105, the first termination second source ground of temperature-sensitive silk S3, and first end of resistance R 46 is the output of temperature sampling unit 105; Second end of the first termination temperature-sensitive silk S3 of resistance R 46, the voltage input end of the second end temperature sampling unit 105 of resistance R 46.

As the utility model one embodiment; Security Unit 106 comprises operational amplifier U21, diode D23, resistance R 47, resistance R 48, diode D26 and diode D27, and the in-phase input end of operational amplifier U21 is connected with the negative electrode of diode D26 and the negative electrode of diode D27 simultaneously, and the anode of diode D26 is first test side of Security Unit 106; The anode of diode D27 is second test side of Security Unit 106;, the output of operational amplifier U21 is the output of Security Unit 106, first end of the positive power source terminal connecting resistance R47 of operational amplifier U11; The negative supply termination second source ground of operational amplifier U11; The anode of diode D23 connects the output of operational amplifier U21, and the negative electrode of diode D23 connects the in-phase input end of operational amplifier U21, and first end of resistance R 47 is the driving voltage input of Security Unit 106; The inverting input of the second termination operational amplifier U21 of resistance R 47, resistance R 48 are connected between second end and second source ground of resistance R 47.

As the utility model one embodiment; Temperature-adjusting constant temperature unit 107 comprises operational amplifier U22, resistance R 49, resistance R 50, adjustable resistance VR3, resistance R 51; The in-phase input end of operational amplifier U22 is the temperature-sensitive voltage input end of temperature-adjusting constant temperature unit 107; The output of operational amplifier U22 is the output of temperature-adjusting constant temperature unit 107; First end of the positive power source terminal connecting resistance R50 of operational amplifier U22; The negative supply termination second source ground of operational amplifier U2, resistance R 49 is connected between the output and inverting input of operational amplifier U22, and first end of resistance R 50 is the driving voltage input of temperature-adjusting constant temperature unit 107; Second end of resistance R 50 is connected with the inverting input of operational amplifier U22 and first end of adjustable resistance VR3 simultaneously, and resistance R 51 is connected between second end and second source ground of adjustable resistance VR3.

As the utility model one embodiment, pressure limiting unit 108 is a Zener diode ZD24, and the negative electrode of Zener diode ZD24 is the input of pressure limiting unit 108, and the anode of Zener diode ZD24 is the output of pressure limiting unit 108.

As the utility model one embodiment; Signal feedback unit 109 comprises diode D24, diode D25, resistance R 52 and photoelectrical coupler IC3; The anode of diode D24 is the safety protection control signal input part of signal feedback unit 109; The anode of diode D25 be signal feedback unit 109 the temperature control signals input; First end of resistance R 52 is the pressure limiting signal input part of signal feedback unit 109, and first end of resistance R 52 is connected the anode of the second termination photoelectrical coupler IC3 interior light emitting diodes of resistance R 52 simultaneously with the negative electrode of diode D24 and the negative electrode of diode D25; The negative electrode of photoelectrical coupler IC3 interior light emitting diodes connects second source ground, and the collector and emitter of the inner phototriode of photoelectrical coupler IC3 is respectively first output and second output of signal feedback unit 109.

As the utility model one embodiment; Open loop protected location 110 comprises resistance R 53, resistance R 54, operational amplifier U23, resistance R 55, Zener diode ZD21, resistance R 56, electrochemical capacitor C25, triode Q23 and resistance R 57; The base stage of triode Q23 is the control end of open loop protected location 110; The base stage of triode Q23 is connected with the inverting input of operational amplifier U23, and the emitter stage of triode Q23 connects the first power supply ground, and resistance R 57 is connected between the base stage and emitter stage of triode Q23; Electrochemical capacitor C25 is connected between the collector and emitter of triode Q23; First end of resistance R 55 is the voltage input end of open loop protected location 110, the in-phase input end of the second termination operational amplifier U23 of resistance R 55, and resistance R 56 is connected between the inverting input of first end and operational amplifier U23 of resistance R 55; Negative electrode while and the in-phase input end of operational amplifier U23 and first end of resistance R 54 of Zener diode ZD21; The anode of Zener diode ZD21 connects the first power supply ground, and first end of resistance R 53 is the output of open loop protected location 110, and second end of resistance R 53 is connected with the output of operational amplifier U23 and second end of resistance R 54 simultaneously; First section of the positive power source terminal connecting resistance R55 of operational amplifier U23, the negative supply termination first power supply ground of operational amplifier U23.

As the utility model one embodiment; Pwm unit 111 comprises resistance R 58, capacitor C 26, oscillating circuit OSC3, operational amplifier U24, resistance R 38, resistance R 39, trigger TR1, latch LK3, NAND gate NAND4, NAND gate NAND5, driver DR4 and driver DR5; First end of resistance R 58 is first voltage input end of pwm unit 111; Second end of resistance R 58 is connected with the input of oscillating circuit OSC3, the positive pole of capacitor C 26 and the in-phase input end of operational amplifier U24 simultaneously; The negative pole of capacitor C 26 connects the first power supply ground; The output of oscillating circuit OSC3 is connected with the input of trigger TR2, the S input of latch LK3, second input of NAND gate NAND4 and second input of NAND gate NAND5 simultaneously, and first end of resistance R 59 is the control signal input of pwm unit 111, and second end of resistance R 59 is connected with the inverting input of operational amplifier U24 and first end of resistance R 60 simultaneously; Second termination, the first power supply ground of resistance R 60; The R input of the output termination latch LK3 of operational amplifier U24,, first end of the positive power source terminal connecting resistance R58 of operational amplifier U24; The negative supply termination first power supply ground of operational amplifier U24; The reversed-phase output QB of latch LK3 is connected with the 3rd input of NAND gate NAND4 and the 3rd input of NAND gate NAND5 simultaneously, and the in-phase output end Q sky of latch LK3 connects, and the reversed-phase output QB of trigger TR2 connects the first input end of NAND gate NAND4; The in-phase output end Q of trigger TR2 connects the first input end of NAND gate NAND5; The output of the input termination NAND gate NAND4 of driver DR4, the positive power source terminal of driver DR4 is second voltage input end of pwm unit 111, the output of the output of driver DR4 and driver DR5 constitutes the signal end of pwm unit 111; The negative power end of driver DR4 is connected with the negative power end of driver DR5; The output of the input termination NAND gate NAND5 of driver DR5, the positive power source terminal of the driver connected DR4 of positive power source terminal of driver DR5, the negative supply termination first power supply ground of driver DR5.

As the utility model one embodiment; First voltage regulation unit 112 comprises the ancillary coil of resistance R 61, electrochemical capacitor C27, Zener diode ZD22, resistance R 62, Zener diode ZD23, electrochemical capacitor C28, resistance R 63, rectifier bridge BD22 and transformer T21; First end of resistance R 61 is the input of first voltage regulation unit 112; The negative electrode of Zener diode ZD22 is first output of first voltage regulation unit 112; The anodal of electrochemical capacitor C27 is connected with the negative electrode of Zener diode ZD22 and first end of resistance R 62 simultaneously; The negative pole of electrochemical capacitor C27 is connected with the first power supply ground with the anode of Zener diode ZD22 simultaneously; The negative electrode of Zener diode ZD23 is second output of first voltage regulation unit 112, and the negative electrode of Zener diode ZD23 is connected with second end of resistance R 62 and the positive pole of electrochemical capacitor C28 simultaneously, and the anode of Zener diode ZD23 is connected with the first power supply ground with the negative pole of electrochemical capacitor C28 simultaneously; First end of resistance R 63 is connected with second end of resistance R 61 and the positive pole of electrochemical capacitor C27 simultaneously; The positive voltage output end of the second termination rectifier bridge BD22 of resistance R 63, the first input end of rectifier bridge BD22 and second input are connected the negative voltage output termination first power supply ground of rectifier bridge BD22 with first end 6 of the ancillary coil of transformer T21 respectively with second end 7.

As the utility model one embodiment; Second voltage regulation unit 113 comprises triode Q24, resistance R 64, Zener diode ZD25 and electrochemical capacitor C29; The current collection of triode Q24 is the input of second voltage regulation unit 113 very; The emission of triode Q24 is the output of second voltage regulation unit 113 very; Resistance R 64 is connected between the negative electrode of colelctor electrode and Zener diode ZD25 of triode Q24, and the anode of Zener diode ZD25 is connected with negative pole and the second source ground of electrochemical capacitor C29 simultaneously, and the positive pole of electrochemical capacitor C29 connects the emitter stage of triode Q24.

Low pressure constant temperature control device 100 also comprises resistance R 68 and resistance R 69, and resistance R 68 is connected between the control end of output and switching tube Q21 of driver DR4, and resistance R 69 is connected between the control end of output and switching tube Q22 of driver DR5.

High Level AC Voltage gets into high-voltage rectifying filter unit 101 by AC power 200; Through rectifier bridge BD21 High Level AC Voltage is carried out the high voltage direct current that rectification output is mingled with ripple current and interfering signal, carry out exporting high voltage direct current stably after the filtering through capacitor C 21 subsequently; High voltage direct current gets into first voltage regulation unit 112 and power converter unit 102 through the input of resistance R 61 and switching tube Q21 respectively stably; First voltage regulation unit 112 carries out dividing potential drop through the high voltage direct current of 61 pairs of inputs of resistance R; Undertaken behind the voltage regulation filtering operating voltage being provided by Zener diode ZD23 and electrochemical capacitor C28 for the driver DR4 of pwm unit 111 and driver DR5; By resistance R 62 dividing potential drops, Zener diode ZD22 and electrochemical capacitor C27 carry out behind the voltage regulation filtering operating voltage being provided and reference voltage being provided for operational amplifier U24 for the oscillating circuit OSC3 of pwm unit 111 and open loop protected location 110.

Power converter unit 102 is half bridge power converter; The high voltage direct current of input converts thereof into low-voltage AC by switching tube Q21 and switching tube Q22 alternation switch task driven transformer T21 and exports lower pressure rectifier filter unit 103 to; Diode D21 and diode D22 are clamp diode; Be used to suppress the peak voltage of switching tube Q21 and the generation of switching tube Q22 shutdown moment, protection switch pipe Q21 and switching tube Q22.

Lower pressure rectifier filter unit 103 carries out rectification through diode D21 and diode D22 to low-voltage AC, and is carried out for heating wire 300 stable low-voltage DC being provided after the filtering with electrochemical capacitor C24 by inductance L 2.

Voltage sampling unit 104 is through the resistance R 44 and the low-voltage DC of 45 pairs of lower pressure rectifier filter units of resistance R, the 103 outputs dividing potential drop of connecting, and the partial pressure value of resistance R 45 first ends gets into Security Unit 106 as the output signal through diode D26.

Temperature sampling unit 105 through resistance R 46 and temperature-sensitive silk S3 to the operating voltage that provides by second voltage regulation unit 113 dividing potential drop of connecting; When the partial pressure value on the temperature-sensitive silk S3 gets into temperature control signals generative circuit 107 as the output signal; It is through diode D27 entering Security Unit 106, and during the temperature of temperature-sensitive silk S3 induced electricity heated filament 300, its resistance value can change with the variations in temperature of heating wire 300; Therefore, the partial pressure value of temperature-sensitive silk S3 also can change with the variations in temperature of heating wire 300.

Second voltage regulation unit 113 is that Security Unit 106 and temperature-adjusting constant temperature unit 107 provide operating voltage through the mu balanced circuit of being made up of resistance R 64, triode Q24, Zener diode ZD25 and electrochemical capacitor C29.

In Security Unit 106; The operating voltage that is provided by second voltage regulation unit 113 is carried out after the dividing potential drop reference voltage as the inverting input of operational amplifier U21 through resistance R 47 and resistance R 48; When the voltage of lower pressure rectifier filter unit 103 output surpasses 36V or diode D21 or diode D22 can not rectification the time; The reference voltage of the inverting input of operational amplifier U21 will be less than the voltage of its in-phase input end; Operational amplifier U21 output this moment high level; This high level is as the first output entering pwm unit 111 of safety protection control signal through signal feedback unit 109; In like manner, when the temperature of sensing heating wire 300 as temperature-sensitive silk S3 is higher than maximum temperature capping value or temperature-sensitive silk S3 and heating wire 300 when being short-circuited, the reference voltage of operational amplifier U21 inverting input will be less than the voltage of its in-phase input end; Operational amplifier U21 output this moment high level, this high level is as the first output entering pwm unit 111 of safety protection control signal through signal feedback unit 109; Diode D23 is used to lock operational amplifier U21 and keeps the high level output state, till fault eliminating and circuit reset.

The resistance R 50 of 107 inside, temperature-adjusting constant temperature unit; After adjustable resistance VR3, resistance R 51 series connection operating voltage of second voltage regulation unit, 113 outputs is carried out dividing potential drop; The dividing potential drop summation of adjustable resistance VR3 and resistance R 51 is as the inverting input of reference voltage input operational amplifier U22; Operational amplifier U22 carries out voltage error through the temperature-sensitive dc signal that the reference voltage and the in-phase input end of its inverting input input are imported and relatively amplifies, and the signal of telecommunication after will amplifying is as the first output entering pwm unit 111 of temperature control signals through signal feedback unit 109;

In open loop protected location 110; When low pressure constant temperature control device 100 operate as normal; Triode Q23 conducting, operational amplifier U23 exports high level, when low pressure constant temperature control device 100 open loop faults; The 109 no feedback signal outputs of signal feedback unit; Triode Q23 ends, and charged when electrochemical capacitor C25 voltage be higher than Zener diode ZD21 through resistance R 56 pair electrochemical capacitor C25s by the operating voltage of first voltage regulation unit, 112 inputs this moment, and operational amplifier U23 controls signal to pwm unit 111 through resistance R 53 output low levels as the open loop protection.

In the pwm unit 111; Oscillating circuit OSC3 is that latch LK3, trigger TR2, NAND gate NAND4 and NAND gate NAND5 provide benchmark oscillating impulse clock signal, and the frequency values of the benchmark oscillating impulse clock signal of oscillating circuit OSC2 output is by the appearance value decision of the resistance and the capacitor C 26 of resistance R 58; Operational amplifier U24 compares output to the signal from its in-phase input end and inverting input; The pulse sequence signal of a variation is provided for latch LK3; Resistance R 59 is the signal dividing potential drop damping resistance of pwm unit 111 inputs with resistance R 60, and latch LK3 latchs output according to the Different Logic sequential of its R input and the input of S input; Trigger TR2 converts benchmark oscillating impulse clock signal to two the pulse sequence signals that replace each other from its in-phase output end Q and the output of reversed-phase output QB output; NAND gate NAND4 and NAND gate NAND5 drive signal according to the input timing output pulse width of three inputs, pass through the switching tube Q21 and the switching tube Q22 alternation of driver DR4 and driver DR5 driving power converter unit 102 again.When pwm unit 111 receive by signal feedback unit 109 input from the safety protection control signal of Security Unit 106 time; This safety protection control signal gets into the inverting input of operational amplifier U24 through resistance R 59; And convert this safety protection control signal to the two-way pwm control signal and export driver DR4 and driver DR5 respectively to by the combinational circuit that latchs the pulsewidth modulation function that has that operational amplifier U24, trigger TR2, latch LK3, NAND gate NAND4 and NAND gate NAND5 are constituted, driver DR4 and driver DR5 export the two-way pwm control signal to the control end of switching tube Q21 and the control end of switching tube Q22; When pwm unit 111 receive by signal feedback unit 108 input from the temperature control signals of temperature-adjusting constant temperature unit 107 time, also adopt as safety protection control Signal Processing mode carried out temperature control signals handle the back and export the two-way pwm control signal to the control end of switching tube Q21 and the control end of switching tube Q22 respectively by driver DR4 and driver DR5; When low pressure constant temperature control device 100 open loop faults; Pwm unit 111 receives the open loop protection control signal from open loop protected location 110; Also adopt as safety protection control Signal Processing mode is carried out open loop protection control signal processing back and export the two-way pwm control signal to the control end of switching tube Q21 and the control end of switching tube Q22 respectively by driver DR4 and driver DR5; Switching tube Q21 in the power converter unit 102 and the switching tube Q22 control end through separately receives from the two-way pwm control signal of driver DR4 and driver DR5 and exports corresponding duty cycle pulse; Thereby the voltage transformation coefficient of control power converter unit 102 reaches the purpose of controlling output DC voltage.

The utility model embodiment also provides a kind of electric blanket that comprises above-mentioned low pressure constant temperature control device.

The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection domain of the utility model.

Claims

1. low pressure constant temperature control device, external AC power supply and heating wire is characterized in that, said low pressure constant temperature control device comprises:

The temperature-sensitive end is responded to the variations in temperature of said heating wire, produces corresponding temperature-sensitive voltage according to the variations in temperature of said heating wire, and to the take a sample temperature sampling unit of output of said temperature-sensitive voltage;

The output of the said lower pressure rectifier filter unit of input termination is used for the output voltage of said lower pressure rectifier filter unit is limited to 36V with interior pressure limiting unit;

The safety protection control signal input part connects the output of said Security Unit; The output of the said temperature-adjusting constant temperature of temperature control signals input termination unit; The pressure limiting signal input part connects the output of said pressure limiting unit; To the safety protection control signal that said Security Unit generates, the temperature control signals that pressure limiting signal that the pressure limiting unit generates and temperature-adjusting constant temperature unit generate feeds back the signal feedback unit of output;

2. low pressure constant temperature control device as claimed in claim 1; It is characterized in that; Said high-voltage rectifying filter unit comprises rectifier bridge BD1 and electrochemical capacitor C1; The input of said rectifier bridge BD1 is the input of said high-voltage rectifying filter unit, and the positive voltage output end of said rectifier bridge BD1 is the output of said high-voltage rectifying filter unit, the negative voltage output termination first power supply ground of said rectifier bridge BD1; The positive pole of said electrochemical capacitor C1 connects the output of said rectifier bridge BD1, and the negative pole of said electrochemical capacitor C1 connects the first power supply ground;

Said voltage sampling unit comprises resistance R 2 and resistance R 3; First end of said resistance R 2 is the input of voltage sampling unit; Second end of said resistance R 2 is the output of said voltage sampling unit, and said resistance R 3 is connected between second end and second source ground of said resistance R 2;

Said temperature sampling unit comprises temperature-sensitive silk S1 and resistance R 4; Said temperature-sensitive silk S1 is the temperature-sensitive end of said temperature sampling unit; The first termination second source ground of said temperature-sensitive silk S1; First end of said resistance R 4 is the output of said temperature sampling unit, second end of the said temperature-sensitive silk of first termination S1 of said resistance R 4, and second end of said resistance R 4 is the voltage input end of said temperature sampling unit;

Said Security Unit comprises operational amplifier U1, diode D3, resistance R 5, resistance R 6, diode D7 and diode D8; The in-phase input end of said operational amplifier U1 is connected with the negative electrode of said diode D7 and the negative electrode of said diode D8 simultaneously; The anode of said diode D7 is first test side of Security Unit; The anode of said diode D8 is second test side of Security Unit;, the output of said operational amplifier U1 is the output of said Security Unit, first end of the said resistance R 5 of positive supply termination of said operational amplifier U1; The negative supply termination second source ground of said operational amplifier U1; The anode of said diode D3 connects the output of said operational amplifier U1, and the negative electrode of said diode D3 connects the in-phase input end of said operational amplifier U1, and first end of said resistance R 5 is the second driving voltage input of said Security Unit 106; The inverting input of the said operational amplifier U1 of second termination of said resistance R 5, said resistance R 6 are connected between second end and second source ground of said resistance R 5;

Said temperature-adjusting constant temperature unit comprises operational amplifier U2, resistance R 7, resistance R 8, adjustable resistance VR1, resistance R 9; The in-phase input end of said operational amplifier U1 is the temperature-sensitive voltage input end of said temperature-adjusting constant temperature unit; The output of said operational amplifier U2 is the output of said temperature-adjusting constant temperature unit; First section of the said resistance R 8 of positive supply termination of said operational amplifier U2; The negative supply termination second source ground of said operational amplifier U2; Said resistance R 7 is connected between the output and inverting input of said operational amplifier U2; First end of said resistance R 8 is the driving voltage input of said temperature-adjusting constant temperature unit, and second end of said resistance R 8 is connected with the inverting input of said operational amplifier U2 and first end of said adjustable resistance VR1 simultaneously, and said resistance R 9 is connected between second end and second source ground of said adjustable resistance VR1;

Said pressure limiting unit is a Zener diode ZD5, and the negative electrode of said Zener diode ZD5 is the input of said pressure limiting unit, and the anode of said Zener diode ZD5 is the output of said pressure limiting unit;

Said signal feedback unit comprises diode D4, diode D5, resistance R 10 and photoelectrical coupler IC1; The anode of said diode D4 is the safety protection control signal input part of said signal feedback unit; The anode of said diode D5 be said signal feedback unit the temperature control signals input; First end of said resistance R 10 is the pressure limiting signal input part of said signal feedback unit; First end of said resistance R 10 is connected with the negative electrode of said diode D4 and the negative electrode of said diode D5 simultaneously; The anode of the said photoelectrical coupler IC1 of second termination interior light emitting diodes of said resistance R 10; The negative electrode of said photoelectrical coupler IC1 interior light emitting diodes connects second source ground, and the collector and emitter of the inner phototriode of said photoelectrical coupler IC1 is respectively first output and second output of said signal feedback unit;

Said open loop protected location comprises resistance R 11, resistance R 12, operational amplifier U3, resistance R 13, Zener diode ZD1, resistance R 14, electrochemical capacitor C4, triode Q2 and resistance R 15; The base stage of said triode Q2 is the control end of said open loop protected location; The base stage of said triode Q2 is connected with the inverting input of said operational amplifier U3; The emitter stage of said triode Q2 connects the first power supply ground; Said resistance R 15 is connected between the base stage and emitter stage of said triode Q2; Said electrochemical capacitor C4 is connected between the collector and emitter of said triode Q2; First end of said resistance R 13 is the voltage input end of said open loop protected location, the in-phase input end of the said operational amplifier U3 of second termination of said resistance R 13, and said resistance R 14 is connected between the inverting input of first end and said operational amplifier U3 of said resistance R 13; Negative electrode while and the in-phase input end of said operational amplifier U3 and first end of said resistance R 12 of said Zener diode ZD1; The anode of said Zener diode ZD1 connects the first power supply ground, and first end of said resistance R 11 is the output of said open loop protected location, and second end of said resistance R 11 is connected with the output of said operational amplifier U3 and second end of said resistance R 12 simultaneously; First end of the said resistance R 13 of positive supply termination of said operational amplifier U3, the negative supply termination first power supply ground of said operational amplifier U3;

Said second voltage regulation unit comprises triode Q3, resistance R 22, Zener diode ZD6 and electrochemical capacitor C8; The input of very said second voltage regulation unit of the current collection of said triode Q3; The output of very said second voltage regulation unit of the emission of said triode Q3; Said resistance R 22 is connected between the negative electrode of colelctor electrode and said Zener diode ZD6 of said triode Q3; The anode of said Zener diode ZD6 is connected with negative pole and the second source ground of said electrochemical capacitor C8 simultaneously, and the positive pole of said electrochemical capacitor C8 connects the emitter stage of said triode Q3.

3. low pressure constant temperature control device as claimed in claim 1; It is characterized in that; Said power converter unit comprises capacitor C 2, resistance R 1, diode D1, transformer T1, switching tube Q1 and resistance R 2; First end of the primary coil of said transformer T1 is the voltage input end of said power converter unit; The anode of said diode D1 is connected with first end of said resistance R 1 with the primary coil of transformer T1 through the said capacitor C 2 of parallel connection; First end of the secondary coil of said transformer T1 is the output of said power converter unit, the second termination second source ground of the secondary coil of said transformer T1, negative electrode while and second end of the primary coil of said transformer T1 and the input of said switching tube Q1 of said diode D1; The control end of said switching tube Q1 and output constitute the control end of said power converter unit, and said resistance R 2 is connected between the output and the first power supply ground of said switching tube Q1;

Said lower pressure rectifier filter unit comprises diode D2 and electrochemical capacitor C3; The anode of said diode D2 is the input of said lower pressure rectifier filter unit; The negative electrode of said diode D2 is the output of said lower pressure rectifier filter unit, and said electrochemical capacitor C3 is connected between the negative electrode and second source ground of said diode D2;

Said pwm unit comprises resistance R 16, resistance R 17, Zener diode ZD2, operational amplifier U4, resistance R 18, capacitor C 5, oscillating circuit OSC1, latch LK1, NAND gate NAND1 and driver DR1; First end of said resistance R 16 is the control signal input of said pwm unit; The negative electrode of said Zener diode ZD2 is connected with second end of said resistance R 16, first end of said resistance R 17 and the inverting input of said operational amplifier U4 simultaneously; The anode of said Zener diode ZD2 is connected with the first power supply ground with second end of said resistance R 17 simultaneously; First end of the said resistance R 18 of positive supply termination of said operational amplifier U4; The negative supply termination first power supply ground of said operational amplifier U4; First end of said resistance R 18 is first voltage input end of said pwm unit; The anodal of said capacitor C 5 is connected with second end of said resistance R 18 and the input of said oscillating circuit OSC1 simultaneously; The negative pole of said capacitor C 5 connects the first power supply ground, and the output of said oscillating circuit OSC1 is connected with the S input of said latch LK1 and the first input end of said NAND gate NAND1 simultaneously, the output of the said operational amplifier U4 of R input termination of said latch LK1; The reversed-phase output of said latch LK1 connects second input of said NAND gate NAND1; The in-phase output end sky of said latch LK1 connects, and the input of the said driver DR1 of output termination of said NAND gate NAND1, the positive power source terminal of said driver DR1 are second voltage input end of said pwm unit; The in-phase input end of the output of said driver DR1 and said operational amplifier U4 constitutes the signal output part of said pwm unit, the negative supply termination first power supply ground of said driver DR1;

Said first voltage regulation unit comprises the ancillary coil of resistance R 19, electrochemical capacitor C6, Zener diode ZD3, resistance R 20, Zener diode ZD4, electrochemical capacitor C7, resistance R 21, diode D6 and transformer T1; First end of said resistance R 19 is the input of said first voltage regulation unit; First output of just very said first voltage regulation unit of said electrochemical capacitor C6; The negative electrode of said Zener diode ZD3 is second output of said first voltage regulation unit; Anodal while and the negative electrode of said Zener diode ZD3 and first end of said resistance R 20 of said electrochemical capacitor C6; The negative pole of said electrochemical capacitor C6 is connected with the first power supply ground with the anode of said Zener diode ZD3 simultaneously; The negative electrode of said Zener diode ZD4 is connected with second end of said resistance R 20 and the positive pole of said electrochemical capacitor C7 simultaneously; The anode of said Zener diode ZD4 is connected with the first power supply ground with the negative pole of said electrochemical capacitor C7 simultaneously, and first end of said resistance R 21 is connected with second end of said resistance R 19 and the positive pole of said electrochemical capacitor C7 simultaneously, and the negative electrode of said diode D6 connects second end of said resistance R 21; The anode of said diode D6 connects first end of the secondary coil of transformer T1, second termination, the first power supply ground of the secondary coil of said transformer T1.

4. switching tube Q1 as claimed in claim 3 is characterized in that, said switching tube Q1 is a N type metal-oxide-semiconductor, and control end, input and the output of the said pipe Q1 that opens the light be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

5. low pressure constant temperature control device as claimed in claim 1; It is characterized in that; Said power converter unit comprises switching tube Q11, switching tube Q12, transformer T11; The control end of the control end of said switching tube Q11 and said switching tube Q12 constitutes the control end of said power converter unit; First end of the primary coil of the said transformer T11 of input termination of said switching tube Q11; Second end of the primary coil of said transformer T11 is the voltage input end of said power converter unit, and first end of the secondary coil of said transformer T11 and the 3rd end are the output of said power converter unit, the second termination second source ground of the secondary coil of said transformer T11; The output of said switching tube Q11 is connected the 3rd end of the primary coil of the said transformer T11 of input termination of said switching tube Q12 with the output of said switching tube Q12 simultaneously with the first power supply ground;

Said lower pressure rectifier filter unit comprises diode D11, diode D12, inductance L 1 and electrochemical capacitor C12; The anode of the anode of said diode D11 and said diode D12 is formed the input of said lower pressure rectifier filter unit; The anode of said diode D11 connects first end of the secondary coil of said transformer T11; The anode of said diode D12 connects the 3rd end of the secondary coil of said transformer T11; First end of said inductance L 1 is connected with the negative electrode of said diode D11 and the negative electrode of said diode D12 simultaneously; Second end of said inductance L 1 is the output of said lower pressure rectifier filter unit, and the positive pole of said electrochemical capacitor C12 connects second end of said inductance L 1, and the negative pole of said electrochemical capacitor C12 connects second source ground;

Said pwm unit comprises resistance R 37, capacitor C 14, oscillating circuit OSC2, operational amplifier U14, resistance R 38, resistance R 39, trigger TR1, latch LK2, NAND gate NAND2, NAND gate NAND3, driver DR2 and driver DR3; First end of said resistance R 37 is first voltage input end of said pwm unit; Second end of said resistance R 37 is connected with the in-phase input end of said operational amplifier U14 with input, the anodal of said capacitor C 14 of said oscillating circuit OSC2 simultaneously; The negative pole of said capacitor C 14 connects the first power supply ground; The output of said oscillating circuit OSC2 is connected with second input of the input of said trigger TR1, the S input of said latch LK2, said NAND gate NAND2 and second input of said NAND gate NAND3 simultaneously; First end of said resistance R 38 is the control signal input of said pwm unit; Second end of said resistance R 38 is connected with the inverting input of said operational amplifier U14 and first end of said resistance R 39 simultaneously; Second termination, the first power supply ground of said resistance R 39; The R input of the said latch LK2 of output termination of said operational amplifier U14; First end of the said resistance R 37 of power supply termination of said operational amplifier U14, the negative supply termination first power supply ground of said operational amplifier U14, the reversed-phase output of said latch LK2 is connected with the 3rd input of said NAND gate NAND2 and the 3rd input of said NAND gate NAND3 simultaneously; The in-phase output end sky of said latch LK2 connects; The reversed-phase output of said trigger TR1 connects the first input end of said NAND gate NAND2, and the in-phase output end of said trigger TR1 connects the first input end of said NAND gate NAND3, the output of the said NAND gate NAND2 of input termination of said driver DR2; The positive power source terminal of said driver DR2 is second voltage input end of said pwm unit; The output of the output of said driver DR2 and said driver DR3 constitutes the signal output part of said pwm unit, and the negative power end of said driver DR2 is connected with the negative power end of said driver DR3, the output of the said NAND gate NAND3 of input termination of said driver DR3; The positive power source terminal of the said driver DR2 of positive supply termination of said driver DR3, the negative supply termination first power supply ground of said driver DR3;

Said first voltage regulation unit comprises the ancillary coil of resistance R 40, electrochemical capacitor C15, Zener diode ZD12, resistance R 41, Zener diode ZD13, electrochemical capacitor C16, resistance R 42, rectifier bridge BD12 and transformer T11; First end of said resistance R 40 is the input of said first voltage regulation unit; The negative electrode of said Zener diode ZD12 is first output of said first voltage regulation unit; The anodal of said electrochemical capacitor C15 is connected with the negative electrode of said Zener diode ZD12 and first end of said resistance R 41 simultaneously; The negative pole of said electrochemical capacitor C15 is connected with the first power supply ground with the anode of said Zener diode ZD12 simultaneously; The negative electrode of said Zener diode ZD13 is second output of said first voltage regulation unit; The negative electrode of said Zener diode ZD13 is connected with second end of said resistance R 41 and the positive pole of said electrochemical capacitor C16 simultaneously; The anode of said Zener diode ZD13 is connected with the first power supply ground with the negative pole of said electrochemical capacitor C16 simultaneously; First end of said resistance R 42 is connected with second end of said resistance R 40 and the positive pole of said electrochemical capacitor C16 simultaneously; The positive voltage output end of the said rectifier bridge BD12 of second termination of said resistance R 42, the first input end of said rectifier bridge BD12 and second input are connected with second end with first end of the ancillary coil of said transformer T11 respectively, and the negative voltage output termination of said rectifier bridge BD12 connects the first power supply ground.

6. power converter unit as claimed in claim 5; It is characterized in that; Said switching tube Q11 and said switching tube Q12 are N type metal-oxide-semiconductor; The control end of said switching tube Q11, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively, and the control end of said switching tube Q12, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

7. low pressure constant temperature control device as claimed in claim 1; It is characterized in that; Said power converter unit 102 comprises switching tube Q21, switching tube Q22, diode D21, diode D22, capacitor C 22, capacitor C 23 and transformer T21; The control end of the control end of said switching tube Q21 and said switching tube Q22 constitutes the control end of said power converter unit; The input of said switching tube Q21 is the voltage input end of said power converter unit; First end of the input while of said switching tube Q22 with the primary coil of the negative electrode of the anode of the output of said switching tube Q21, said diode D21, said diode D22 and said transformer T21 is connected; The output of said switching tube Q22 is connected with the anode of said diode D22, first end and first power end of said capacitor C 22 simultaneously; The negative electrode of said diode D21 is connected with the input of said switching tube Q21 and first end of said capacitor C 23 simultaneously; Second end while of said capacitor C 23 is connected with second end of the primary coil of said transformer T21 and second end of said capacitor C 22, and first end of the secondary coil of said transformer T21 and the 3rd end are the output of said power converter unit, the second termination second source ground of the secondary coil of said transformer T21;

Said lower pressure rectifier filter unit comprises diode D21, diode D22, inductance L 2 and electrochemical capacitor C24; The anode of the anode of said diode D21 and said diode D22 is formed the input of said lower pressure rectifier filter unit; The anode of said diode D21 connects first end of the secondary coil of said transformer T21; The anode of said diode D22 connects the 3rd end of the secondary coil of said transformer T21; First end of said inductance L 2 is connected with the negative electrode of said diode D21 and the negative electrode of said diode D22 simultaneously; Second end of said inductance L 2 is the output of said lower pressure rectifier filter unit, and the positive pole of said electrochemical capacitor C24 connects second end of said inductance L 2, and the negative pole of said electrochemical capacitor C24 connects second source ground;

Said pwm unit comprises resistance R 58, capacitor C 26, oscillating circuit OSC3, operational amplifier U24, resistance R 38, resistance R 39, trigger TR1, latch LK3, NAND gate NAND4, NAND gate NAND5, driver DR4 and driver DR5; First end of said resistance R 58 is first voltage input end of said pwm unit; Second end of said resistance R 58 is connected with the in-phase input end of said operational amplifier U24 with input, the anodal of said capacitor C 26 of said oscillating circuit OSC3 simultaneously; The negative pole of said capacitor C 26 connects the first power supply ground; The output of said oscillating circuit OSC3 is connected with second input of the input of said trigger TR2, the S input of said latch LK3, said NAND gate NAND4 and second input of said NAND gate NAND5 simultaneously; First end of said resistance R 59 is the control signal input of said pwm unit; Second end of said resistance R 59 is connected with the inverting input of said operational amplifier U24 and first end of said resistance R 60 simultaneously; Second termination, the first power supply ground of said resistance R 60; The R input of the said latch LK3 of output termination of said operational amplifier U24; First end of the said resistance R 58 of positive supply termination of said operational amplifier U24; The reversed-phase output of the said latch LK3 in the negative supply termination first power supply ground of said operational amplifier U24 is connected with the 3rd input of said NAND gate NAND4 and the 3rd input of said NAND gate NAND5 simultaneously, and the in-phase output end sky of said latch LK3 connects, and the reversed-phase output of said trigger TR2 connects the first input end of said NAND gate NAND4; The in-phase output end of said trigger TR2 connects the first input end of said NAND gate NAND5; The output of the said NAND gate NAND4 of input termination of said driver DR4, the positive power source terminal of said driver DR4 are second voltage input end of said pwm unit, and the output of the output of said driver DR4 and said driver DR5 constitutes the signal output part of said pwm unit; The negative power end of said driver DR4 is connected with the negative power end of said driver DR5; The output of the said NAND gate NAND5 of input termination of said driver DR5, the positive power source terminal of the said driver DR4 of positive supply termination of said driver DR5, the negative supply termination first power supply ground of said driver DR5;

Said first voltage regulation unit comprises the ancillary coil of resistance R 61, electrochemical capacitor C27, Zener diode ZD22, resistance R 62, Zener diode ZD23, electrochemical capacitor C28, resistance R 63, rectifier bridge BD22 and transformer T21; First end of said resistance R 61 is the input of said first voltage regulation unit; The negative electrode of said Zener diode ZD22 is first output of said first voltage regulation unit; The anodal of said electrochemical capacitor C27 is connected with the negative electrode of said Zener diode ZD22 and first end of said resistance R 62 simultaneously; The negative pole of said electrochemical capacitor C27 is connected with first power supply with the anode of said Zener diode ZD22 simultaneously; The negative electrode of said Zener diode ZD23 is second output of said first voltage regulation unit; The negative electrode of said Zener diode ZD23 is connected with second end of said resistance R 62 and the positive pole of said electrochemical capacitor C28 simultaneously; The anode of said Zener diode ZD23 is connected with the first power supply ground with the negative pole of said electrochemical capacitor C28 simultaneously; First end of said resistance R 63 is connected with second end of said resistance R 61 and the positive pole of said electrochemical capacitor C27 simultaneously; The positive voltage output end of the said rectifier bridge BD22 of second termination of said resistance R 63, the first input end of said rectifier bridge BD22 and second input are connected the negative voltage output termination first power supply ground of said rectifier bridge BD22 with first end of the ancillary coil of said transformer T21 respectively with second end.

8. power converter unit as claimed in claim 7; It is characterized in that; Said switching tube Q21 and said switching tube Q22 are N type metal-oxide-semiconductor; The control end of said switching tube Q21, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively, and the control end of said switching tube Q22, input and output be grid, drain electrode and the source electrode of corresponding N type metal-oxide-semiconductor respectively.

9. an electric blanket is characterized in that, said electric blanket comprises each described low pressure constant temperature control device of aforesaid right requirement 1-8.