CN202171757U - DC (direct current) voltage stabilization power source capable of adjusting voltage - Google Patents

Abstract

The utility model relates to the field of electricity, in particular to a DC (direct current) voltage stabilization power source capable of adjusting voltage. A voltage setting circuit is connected with a switch power source or a linear power source by setting resistance in the switch power source or the linear power source for generating a setting voltage; and the control unit is used for controlling the setting voltage output by the voltage setting circuit according to sampled voltage and/or current information. In embodiments of the DC voltage stabilization power source, the output voltage is adjusted in an electronic way, the problems of abrasion, invalidation and the like caused by the adjustment by a mechanical structure in the prior art can be avoided, and the adjustment which is more exact of the power output voltage can be realized by a control chip.

Description

The D.C. regulated power supply that a kind of voltage is adjustable

Technical field

The utility model relates to electricity field, particularly about the adjustable D.C. regulated power supply of a kind of voltage.

Background technology

Direct supply is the indispensable ingredient of each class of electronic devices; Simultaneously in different electronic product R&D processes; The direct supply that possibly need different magnitudes of voltage, therefore adjustable D.C. regulated power supply becomes electronic product and researches and develops one of breadboard indispensable equipment.Also have in the electrical characteristics test of some electronic equipment maintenance occasions, hardware circuit and all need adjustable D.C. regulated power supply.

The method that DC voltage produces is a lot, generally can be divided into two kinds of linear voltage stabilization and switch voltage-stabilizings.The linear DC power supply is to realize that through transistor of series connection between input and output this serial transistor is operated in the linear zone of voltage-current characteristic curve, plays variable-resistance effect.Shown in Figure 1 is the schematic diagram of a kind of linear stabilized power supply in the prior art, and the negative input end of error amplifier connects reference source, and the positive input terminal of error amplifier connects the output feedback, and this feedback is obtained after R1 and R2 dividing potential drop by output voltage.In fact, ideal operational amplificr equates the voltage of positive-negative input end through changing output.Therefore, during stable state, the voltage that connects the node of R1 and R2 can be thought and equals VREF.The input end of supposing operational amplifier does not have electric current to flow out or inflow, can get through Ohm law

$\frac{R2}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1+\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2}=\frac{V_{\mathrm{REF}}}{V_{\mathrm{OUT}}}$

So obtain output voltage be:

$V_{\mathrm{OUT}}=V_{\mathrm{REF}}*(1+\frac{R1}{R2})$ (formula 1)

The control loop theory application in this power supply the time, we only pay close attention to and change (perhaps disturbance), and do not pay close attention to DC quantity.If error amplifier is common voltage feedback operational amplifier, then the next divider resistance R2 is a direct current biasing resistance, in exchanging loop analysis, does not play any (directly) effect.

Switching Power Supply then is to be operated in the transistorized conducting of on off state or the time of shutoff is adjusted output voltage through adjustment.Fig. 2 is the switching power supply schematic diagram of buck topological structure in the prior art, and Fig. 3 is the switching power supply schematic diagram of boost topological structure in the prior art.Can know that from Fig. 2 and Fig. 3 the switching power supply basic circuit comprises error amplifier, reference source, saw-toothed wave generator, PWM comparer, switching tube, diode and inductance etc.Z1 and Z2 are the corrective networks that resistance capacitance is formed among the figure.

During work, output voltage at first pass through behind the resistance sampling network with the internal reference voltage ratio.Both differences are through error amplifier filtering, amplification and upset then, and the output of error amplifier is as one in two inputs of pulse-width modulator (PWM), and another input of PWM comparer is a sawtooth wave.Just obtained the square wave that dutycycle is proportional to the error amplifier output valve at the output terminal of PWM comparer like this, i.e. the variable quantity of PWM comparer output is the switch pulsewidth.So if output is risen, the output voltage of error amplifier descends, dutycycle diminishes so that export and diminish; Otherwise then the output voltage of error amplifier rises, and dutycycle becomes big so that output becomes big.The principle of work of Switching Power Supply regulating system that Here it is.The computing formula of its output voltage is identical with (formula 1).The control loop theory application in this power supply the time, we only pay close attention to and change (perhaps disturbance), and do not pay close attention to DC quantity.If error amplifier is common voltage feedback operational amplifier, then the next divider resistance R2 is a direct current biasing resistance, in exchanging loop analysis, does not play any (directly) effect.

General is that linear stabilized power supply or switching power supply all are through changing the sampling ratio of output voltage to be regulated output voltage values.Common adjustable D.C. regulated power supply adopts many circle mechanical potentiometers as the output voltage adjustment.There is mechanical wear in mechanical potentiometer, is afraid of that vibrations, frequent movement damage easily.

The utility model content

The utility model embodiment provides a kind of voltage adjustable D.C. regulated power supply; Be used for solving and need the switch of physical construction to carry out voltage-regulation in the adjustable D.C. regulated power supply of prior art voltage; Cause mechanical wear, system's problem of unstable of therefore bringing.

The utility model embodiment provides a kind of voltage adjustable D.C. regulated power supply; In Switching Power Supply or linear power supply; First divider resistance in said Switching Power Supply or the linear power supply and second divider resistance feed back to the error amplifier negative input end to output voltage and regulate output voltage, it is characterized in that also comprising:

Set resistance, voltage setting circuit, sample circuit and control module;

Said setting resistance one end is connected in the feedback voltage point between said first divider resistance and said second divider resistance, and the other end is connected in said voltage setting circuit;

Said voltage setting circuit is connected in said Switching Power Supply or the linear power supply through said setting resistance, is used to produce setting voltage, the output voltage of said Switching Power Supply or linear power supply and the said setting voltage linear relationship that is inversely proportional to;

Said sample circuit is parallelly connected with the output terminal of said Switching Power Supply or linear power supply, and said sample circuit sends the voltage and/or the current information of output terminal to control module;

The setting voltage that said control module is controlled said voltage setting circuit output according to the voltage and/or the current information of said sampling.

According to a further aspect of the adjustable D.C. regulated power supply of the described a kind of voltage of the utility model embodiment, the output voltage of said Switching Power Supply or linear power supply and the said setting voltage linear relationship that is inversely proportional to is meant,

$V_{\mathrm{OUT}}=(1+\frac{R1}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2//R3})*V_{\mathrm{REF}}-\frac{R1}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000091.png"\; state="\{\{state\}\}">R</figure-callout>}3}*V_{\mathrm{SET}};$

Wherein VOUT is an output voltage, and VREF is a reference voltage, and VSET is a setting voltage, and R1 is first divider resistance, and R2 is second divider resistance, and R3 is for setting resistance.

Another further aspect according to the adjustable D.C. regulated power supply of the described a kind of voltage of the utility model embodiment; Said Switching Power Supply comprises buck topological structure switching power supply, the inverting power supplies of boost topological structure switching power supply and buck-boost topological structure.

Another further aspect according to the adjustable D.C. regulated power supply of the described a kind of voltage of the utility model embodiment; Said linear power supply comprises; Transistor of series connection between the input end of linear power supply and output terminal, this transistor also connects the output terminal of error amplifier, and the negative input end of said error amplifier connects reference source; The positive input terminal of error amplifier connects the output feedback, and this output feedback is obtained after first divider resistance and the second divider resistance dividing potential drop by output voltage.

Another further aspect according to the adjustable D.C. regulated power supply of the described a kind of voltage of the utility model embodiment; Said transistor is a PNP transistor; The emitter of said PNP transistor connects input end, and collector connects output terminal, and base stage connects the output terminal of error amplifier.

Another further aspect according to the adjustable D.C. regulated power supply of the described a kind of voltage of the utility model embodiment; Said transistor is the PMOS pipe; The transistorized source electrode of said pmos type connects input end, and drain electrode connects output terminal, and grid connects the output terminal of error amplifier.

Through the utility model embodiment, realized the scalable of output voltage, simultaneously, do not change the dynamic property of power-switching circuit feedback again.The voltage setting circuit that adds cuts little ice in the transactional analysis of circuit, so the dynamic property of circuit is unaffected.Through control module sample rate current, voltage signal, realized the overcurrent and the overvoltage protection of output.Through the sampling and outputting voltage signal, relatively the back is regulated by output voltage with the output voltage values of setting, the temperature that can reduce power supply floats, the time float the error of bringing to output with the component parameter tolerance.Setting voltage amount V _SETConvert simulating signal into through pwm signal and obtain, can reduce system cost.The adjusting step pitch of output voltage can be accomplished very high resolving powers such as 12,14 or 16, as long as Value reach same resolving power and get final product, so voltage set amount V _SETResolving power so long as the output voltage resolving power

Doubly get final product.

Description of drawings

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only is some embodiment of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Shown in Figure 1 is the schematic diagram of a kind of linear stabilized power supply in the prior art;

Fig. 2 is the switching power supply schematic diagram of buck topological structure in the prior art;

Fig. 3 is the switching power supply schematic diagram of boost topological structure in the prior art;

Shown in Figure 4 is the structural representation of the adjustable D.C. regulated power supply of a kind of voltage of the utility model embodiment;

Fig. 5 A is depicted as the circuit diagram of the adjustable DC voltage-stabilizing Switching Power Supply of the utility model embodiment voltage;

Fig. 5 B is depicted as the voltage setting circuit circuit diagram of the adjustable DC voltage-stabilizing Switching Power Supply of the utility model embodiment voltage;

Shown in Figure 6 is the circuit diagram of the adjustable DC voltage-stabilizing linear power supply of the utility model embodiment voltage;

Shown in Figure 7 is the circuit diagram of single-chip microcomputer in the adjustable DC-stabilized circuit of the utility model embodiment voltage;

Shown in Figure 8 is the schematic diagram of the adjustable DC voltage-stabilizing linear power supply of the utility model embodiment voltage;

Fig. 9 A is depicted as among the utility model embodiment and is output as+circuit diagram of 6V dc auxiliary supply;

Fig. 9 B is depicted as among the utility model embodiment and is output as+circuit diagram of 5VA accessory power supply;

Fig. 9 C is depicted as among the utility model embodiment and is output as+circuit diagram of 3.3V accessory power supply.

Embodiment

To combine the accompanying drawing among the utility model embodiment below, the technical scheme among the utility model embodiment is carried out clear, intactly description, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the utility model protection.

Be illustrated in figure 4 as the structural representation of the adjustable D.C. regulated power supply of a kind of voltage of the utility model embodiment.

In Switching Power Supply or linear power supply, also comprise and set resistance R 3, voltage setting circuit 400, sample circuit 401, control module 402;

Said setting resistance R 3 one ends are connected in the feedback voltage point between first divider resistance and second divider resistance, and the other end is connected in said voltage setting circuit;

Said voltage setting circuit is connected in said Switching Power Supply or the linear power supply through said setting resistance, is used to produce setting voltage V _SET, the output voltage V of said Switching Power Supply or linear power supply _OUTWith said setting voltage V _SETThe linear relationship that is inversely proportional to through regulating setting voltage, thereby can be regulated the output voltage of said Switching Power Supply or linear power supply.

Said sample circuit 401 is parallelly connected with the output terminal of said Switching Power Supply or linear power supply, and said sample circuit 401 sends the voltage and/or the current information of output terminal to control module 402.

The setting voltage V that said control module 402 is controlled said voltage setting circuit 400 outputs according to the voltage and/or the current information of said sampling _SET

As shown in the figure, in described Switching Power Supply or linear power supply, all comprise error amplifier 403, V _FBBe feedback voltage, Z1, Z2 are the impedances in error amplifier self negative feedback, and the effect of Z1 and Z2 is that the stabilized voltage supply loop is carried out zero pole compensation, to realize good stability and the fast response characteristic of stabilized voltage supply.

The above-mentioned said Switching Power Supply or the output voltage V of linear power supply _OUTWith said setting voltage V _SETThe linear relationship that is inversely proportional to, during steady operation, supposing between Z1 and three resistance nodes does not have electric current to flow through, then V _FBEqual V _REF, so V _OUT, V _FBAnd V _SETTriangular relational expression is derived as follows:

(1) sampling resistor R1, sampling resistor R2, setting resistance R 3;

(2) reference voltage V _REF, setting voltage V _SET

Ask output voltage V _OUTValue.

Superposition principle by circuit gets:

$V_{\mathrm{FB}}=\frac{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2//R3}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1+\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2//\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000091.png"\; state="\{\{state\}\}">R</figure-callout>}3}*V_{\mathrm{OUT}}+\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1//R2}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000091.png"\; state="\{\{state\}\}">R</figure-callout>}3+\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1//R2}{V}_{\mathrm{SET}}$ (formula 2)

Rx//Ry is two resistance values after the resistance parallel connection in the following formula.Parallel resistance in the following formula launched:

$V_{\mathrm{FB}}=\frac{\frac{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2*R3}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2+R3}}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1+\frac{R2*R3}{R2+R3}}*V_{\mathrm{OUT}}+\frac{\frac{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000041.png"\; state="\{\{state\}\}">R</figure-callout>}1*R2}{R1+R2}}{R3+\frac{R1*R2}{R1+R2}}*V_{\mathrm{SET}}$

$\&DoubleRightArrow;V_{\mathrm{FB}}=\frac{R2*R3}{R1*R2+R1*R3+R2*R3}*V_{\mathrm{OUT}}+\frac{R1*R2}{R1*R2+R1*R3+R2*R3}*V_{\mathrm{SET}}$ Will

$\&DoubleRightArrow;(R1*R2+R1*R3+R2*R3)*V_{\mathrm{FB}}=R2*R3*V_{\mathrm{OUT}}+R1*R2*V_{\mathrm{SET}}$

$\&DoubleRightArrow;V_{\mathrm{OUT}}=(1+\frac{R1}{R2//R3})*V_{\mathrm{FB}}-\frac{R1}{R3}*V_{\mathrm{SET}}$

V _FB=V _REFBringing following formula into gets

$V_{\mathrm{OUT}}=(1+\frac{R1}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000074614870000041.png,HDA0000074614870000101.png"\; state="\{\{state\}\}">R</figure-callout>}2//R3})*V_{\mathrm{REF}}-\frac{R1}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000074614870000031.png,HDA0000074614870000091.png"\; state="\{\{state\}\}">R</figure-callout>}3}*V_{\mathrm{SET}}$ (formula 3)

Visible by (formula 3), V _SETWith V _OUTTherefore the linear relationship that is inversely proportional to through setting different given voltage, just can obtain different output voltage, has realized the adjusting of output voltage.

Be depicted as the circuit diagram of the adjustable DC voltage-stabilizing Switching Power Supply of the utility model embodiment voltage like Fig. 5 A.Fig. 5 B is depicted as the voltage setting circuit circuit diagram of the adjustable DC voltage-stabilizing Switching Power Supply of the utility model embodiment voltage.

Wherein the adjustable DC voltage-stabilizing switching power circuit of voltage adopts the buck topological structure; + 24V power supply is partly supplied with by the ACDC power circuit of maturation; The utility model does not have improvement to the ACDC power unit; Can adopt ACDC power circuit of the prior art, so the ACDC part is not described at this.The utility model embodiment also is applicable to the inverting power supplies of boost topological structure switching power supply, buck-boost topological structure; Equally all be between divider resistance, to add to set resistance and correspondent voltage initialization circuit and control module, thus the purpose that realization is regulated output voltage through this variable duty cycle.

Comprise that in Fig. 5 A U2 adopts TPS5430DDA, inductance (L2), fly-wheel diode (VD2), capacitor C 8, C9, resistance R 1, R2 and R3 to constitute the DCDC step-down conversion circuit of buck topology.TPS5430DDA pin 4 when work current potential be clamped at 1.221V, the voltage output formula that the value substitution preceding text (formula 3) of R1, R2 and R3 among Fig. 5 A is obtained Fig. 5 A circuit is (V of unit):

V _OUT=25.641-10*V _SET(formula 4)

Draw V by (formula 4) _SETV during less than 0.1641V _OUTObtain maximal value, i.e. input voltage 24V, V _SETBehind 0.1641V, V _OUTAlong with V _SETIncrease and linearity reduces, its scale-up factor is-10.C6 and C7 are input capacitance; R6 and R9 form the output voltage sampling network, and single-chip microcomputer is sampled to output voltage signal through 12 integrated on sheet analog to digital converters, with to output voltage V _OUTMonitor, in case of necessity to output voltage V _OUTAdjust; U9 adopts INA138NA, R27, R28, R29 and C41 to form the output current sample circuit; Single-chip microcomputer is sampled to output current signal through 12 integrated on sheet analog to digital converters; Realization is to the monitoring and the overcurrent protection of output current, and wherein single-chip microcomputer is the control module described in Fig. 4.

Fig. 5 B is the circuit that contains the pulse width modulating signal revolving die analog signal of 2 rank RC filtering.The PWM ripple driven MOS pipe VT1 of single-chip microcomputer output; Make VT1 be operated on off state; The conducting resistance of ignoring VT1, then its drain electrode end is 0V when its conducting, is 2.5V during shutoff; Therefore the input of 2 rank RC LPFs is that pulse height is the pulse width modulating signal of 2.5V, and DC quantity is delivered to R3 as setting voltage after being amplified by OPA2350 after the filtering.

Be illustrated in figure 6 as the circuit diagram of the adjustable DC voltage-stabilizing linear power supply of the utility model embodiment voltage.

Among Fig. 6, U10 adopts LT1764EQ, capacitor C 12, C13, resistance R 1, R2 and R3 to constitute the linear voltage translation circuit.U10 pin 5 when work current potential be clamped at 1.21V, the voltage output formula that the value substitution preceding text (formula 3) of R1, R2 and R3 among Fig. 6 is obtained Fig. 6 circuit is (V of unit):

V _OUT=27.83-11*V _SET(formula 5)

Draw V by (formula 5) _SETV during less than 0.718V _OUTObtain maximal value, i.e. input voltage 20V, V _SETBehind 0.718V, V _OUTAlong with V _SETIncrease and linearity reduces, its scale-up factor is-11.C30 and C31 are input capacitance; R6 and R9 form output voltage sampling circuit; Single-chip microcomputer is sampled to output voltage signal through 12 integrated on sheet analog to digital converters; So that output voltage is monitored, in case of necessity output voltage is adjusted, only illustrate voltage sampling circuit in the present embodiment; In other embodiment, can also comprise current sampling circuit, the utility model embodiment is provided the overcurrent protection of linear power supply.Wherein, setting voltage V _SETCan adopt the voltage setting circuit among above-mentioned Fig. 5 B to produce, or other voltage generation circuit of the prior art, single-chip microcomputer is the control module described in Fig. 4.

Be illustrated in figure 7 as the circuit diagram of single-chip microcomputer in the adjustable DC-stabilized circuit of the utility model embodiment voltage.

Single-chip microcomputer U7 utilizes self integrated 12 analog to digital converter to realize the sampling to output current voltage; Pin 61 is inputs of sample rate current signal; Pin 60 is inputs of sampled voltage signal, and single-chip microcomputer detects sample rate current above after the setting value, through pin 44 output enable signals; Forbid U2 and turn-off output voltage, realize overcurrent protection; Single-chip microcomputer detects sampled voltage; If, then can carry out regulating and controlling to output voltage because the time drift of the discreteness of component parameter or system or temperature drift etc. cause output to depart from setting value, thus the temperature that reduces system is floated, the time float the influence with the component parameter tolerance; Pin one 8 output pulse width modulation signals (PWM) are to the voltage setting circuit of Fig. 5 B; Thereby obtain setting voltage, this setting voltage is through setting the output voltage of the adjustable D.C. regulated power supply of resistance R 3 control voltages, and pin 44 outputs to the enable signal pin 5 (R7 is passed through in the centre) of U2 (TPS5430DDA); U2 could work when having only pin 44 output high level, exports adjustable voltage.The K1 of keyboard circuit is connected on the pin 20 of U7, and K2 is connected on the pin 21 of U7, and output one default value is pressed K1 key boosted output voltages behind the power supply electrifying, presses the K2 key and reduces output voltage.

Also exist shortcomings such as the precision of pressure regulation difficulty, adjustment is low, consistance difference in the prior art as the adjustment of the voltage of adjustable D.C. regulated power supply.Along with the adjustable direct supply that digital regulation resistance replaces multiturn potentiometer has also appearred in development of electronic technology, but the output resolution of digital regulation resistance is lower, and generally below 10, the adjustment precision can not reach very high level.The resolving power of setting voltage can be 12,14,16 etc. in the utility model embodiment, improve the resolving power of output voltage, as long as improve setting voltage V _SETResolving power get final product.

Be illustrated in figure 8 as the schematic diagram of the adjustable DC voltage-stabilizing linear power supply of the utility model embodiment voltage.

Input end V in the present embodiment _INWith output terminal V _OUTBetween the series connection transistor; This transistor also connects the output terminal of error amplifier; The negative input end of said error amplifier connects reference source; The positive input terminal of error amplifier connects the output feedback, and this output feedback is obtained after first divider resistance and the second divider resistance dividing potential drop by output voltage.Said transistor can be PNP transistor (concrete connected mode is as shown in the figure).Said transistor can also be managed for PMOS, wherein, and input end V _INConnect the emitter E of PNP triode or the source S of PMOS pipe; Output terminal V _OUTThe drain D that connects the collector C or the PMOS pipe of PNP triode; The input end of error amplifier connects the grid G of the base stage B or the PMOS pipe of PNP triode; The positive input terminal of error amplifier connects the common node of R1, R2 and R3; The negative input end of error amplifier connects reference source.

Set resistance R 3 through on divider resistance R1 and R2 tie point, being connected one again, through setting resistance R 3 input setting voltage V _SET, can regulate the output V of DC voltage-stabilizing linear power supply _OUT, and gather the voltage and current of output terminal through control corresponding unit (figure do not show), according to formula 3 output setting voltage V _SETThereby, regulate output voltage V _OUTError amplifier outputs to the base stage (B) of the triode of using as variable resistor or the G utmost point of metal-oxide-semiconductor, regulates resistance value, thereby changes output voltage.

Be depicted as among the utility model embodiment like Fig. 9 A and be output as+circuit diagram of 6V dc auxiliary supply; Be depicted as among the utility model embodiment like Fig. 9 B and be output as+circuit diagram of 5VA accessory power supply; Be depicted as among the utility model embodiment like Fig. 9 C and be output as+circuit diagram of 3.3V accessory power supply; The power circuit that wherein integrated DCDC conversion chip TPS5430 and peripheral inductance thereof, resistance capacitance and diode are formed converts DC voltage+24V to+6VDC; + 6VDC is through linear power supply chip LT1764EQ and affiliated circuit component acquisition+5VA power supply thereof, and+5VA obtains+the 3.3V power supply through linear power supply chip REG1117-3.3 and affiliated circuit component thereof.+ 3.3V gives the single-chip microcomputer and the digital interface power supply of system; + 5VA gives operational amplifier OPA2350 and voltage-reference power supply.

Through the utility model embodiment; Through the electronics mode output voltage is regulated; Thereby problems such as the wearing and tearing of having avoided utilizing in the prior art physical construction to regulate causing, inefficacy, and can realize electric power output voltage is regulated more accurately through control chip.

Above-described embodiment; Purpose, technical scheme and beneficial effect to the utility model have carried out further explain, it should be understood that the above is merely the embodiment of the utility model; And be not used in the protection domain that limits the utility model; All within the spirit and principle of the utility model, any modification of being made, be equal to replacement, improvement etc., all should be included within the protection domain of the utility model.

Claims (6)

1. D.C. regulated power supply that voltage is adjustable; In Switching Power Supply or linear power supply; First divider resistance in said Switching Power Supply or the linear power supply and second divider resistance feed back to the error amplifier negative input end to output voltage and regulate output voltage, it is characterized in that also comprising:

Set resistance, voltage setting circuit, sample circuit and control module;

Said setting resistance one end is connected in the feedback voltage point between said first divider resistance and said second divider resistance, and the other end is connected in said voltage setting circuit;

Said voltage setting circuit is connected in said Switching Power Supply or the linear power supply through said setting resistance, is used to produce setting voltage, the output voltage of said Switching Power Supply or linear power supply and the said setting voltage linear relationship that is inversely proportional to;

Said sample circuit is parallelly connected with the output terminal of said Switching Power Supply or linear power supply, and said sample circuit sends the voltage and/or the current information of output terminal to control module;

The setting voltage that said control module is controlled said voltage setting circuit output according to the voltage and/or the current information of said sampling.

2. the adjustable D.C. regulated power supply of a kind of voltage according to claim 1 is characterized in that, the output voltage of said Switching Power Supply or linear power supply and the said setting voltage linear relationship that is inversely proportional to is meant,

$V_{\mathrm{OUT}}=(1+\frac{R1}{R2//R3})*V_{\mathrm{REF}}-\frac{R1}{R3}*V_{\mathrm{SET}};$

Wherein VOUT is an output voltage, and VREF is a reference voltage, and VSET is a setting voltage, and R1 is first divider resistance, and R2 is second divider resistance, and R3 is for setting resistance.

3. the adjustable D.C. regulated power supply of a kind of voltage according to claim 1 is characterized in that said Switching Power Supply comprises buck topological structure switching power supply, the inverting power supplies of boost topological structure switching power supply and buck-boost topological structure.

4. the adjustable D.C. regulated power supply of a kind of voltage according to claim 1; It is characterized in that said linear power supply comprises, transistor of series connection between the input end of linear power supply and output terminal; This transistor also connects the output terminal of error amplifier; The negative input end of said error amplifier connects reference source, and the positive input terminal of error amplifier connects the output feedback, and this output feedback is obtained after first divider resistance and the second divider resistance dividing potential drop by output voltage.

5. the adjustable D.C. regulated power supply of a kind of voltage according to claim 4; It is characterized in that said transistor is a PNP transistor, the emitter of said PNP transistor connects input end; Collector connects output terminal, and base stage connects the output terminal of error amplifier.

6. the adjustable D.C. regulated power supply of a kind of voltage according to claim 4 is characterized in that, said transistor is the PMOS pipe, and the transistorized source electrode of said pmos type connects input end, and drain electrode connects output terminal, and grid connects the output terminal of error amplifier.

Images