CN203869417U - Electromagnetic door control system for refrigerator - Google Patents
Electromagnetic door control system for refrigerator Download PDFInfo
- Publication number
- CN203869417U CN203869417U CN201420279527.8U CN201420279527U CN203869417U CN 203869417 U CN203869417 U CN 203869417U CN 201420279527 U CN201420279527 U CN 201420279527U CN 203869417 U CN203869417 U CN 203869417U
- Authority
- CN
- China
- Prior art keywords
- resistance
- amplifier
- oxide
- semiconductor
- connects
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Landscapes
- Geophysics And Detection Of Objects (AREA)
Abstract
The utility model discloses an electromagnetic door control system for a refrigerator. The electromagnetic door control system comprises a door controller, a driving inductor, a door sensor and two touch sensors which are independent from each other and can operate different functions synchronously. The door controller is a microprocessor. The driving inductor is an MOSFETH bridge. The door sensor is a magnetic sensor. The touch sensors are RC contact type sensors. The door controller is connected with the driving inductor, the magnetic sensor and the two touch sensors through corresponding pins on the microprocessor. The door controller of the system responds to requests of the two touch sensors, uses the driving inductor to open a door according to the requests and turns off the driving inductor when it is judged that the refrigerator door is closed. According to the system, a user can open the refrigerator door easily. The system is efficient, reliable, practical and low in cost.
Description
Technical field
The utility model relates to a kind of control system, is specifically related to a kind of refrigerator electromagnetic door control system.
Background technology
In daily life; people can run into such situation conventionally; shut again when opening after refrigerator doors; by the time rethink next time and open refrigerator doors; but it is very painstaking to find, this is because last refrigerator while opening, hot-air enter the variation that has caused refrigerator internal pressure; inside and outside refrigerator, form pressure differential, thereby made user be difficult for again opening the door.
Utility model content
The problem that is difficult for reopening in order to solve refrigerator doors, the utility model aims to provide a kind of refrigerator electromagnetic door control system.
For realizing above-mentioned technical purpose, reach above-mentioned technique effect, the utility model is achieved through the following technical solutions:
A kind of refrigerator electromagnetic door control system, comprises a door controller taking microprocessor as core, and described door controller is connected with respectively one and drives inductance, magnetic sensor, a RC touch sensor and the 2nd RC touch sensor.
Described microprocessor comprises the first pwm signal output pin, the second pwm signal output pin, the first binary condition pin, the second binary condition pin, ADC input pin, the first input pin and the second input pin.
Described driving inductance mainly comprises a H electric bridge, described H electric bridge comprises first, second, third, fourth switch, there is first, second, third, fourth inverse-excitation type diode at the two ends of first, second, third, fourth described switch respectively corresponding cross-over connection, power supply is accessed respectively in one end of described first, second switch, the other end accesses respectively load end, load end is accessed respectively in one end described the 3rd, the 4th switch, and the other end is ground connection respectively;
Described the first switch comprises a NPN type triode and a P type metal-oxide-semiconductor, the drain electrode access load end of a described P type metal-oxide-semiconductor, its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of a described NPN type triode, between the source electrode of a described P type metal-oxide-semiconductor and drain electrode, cross-over connection has described the first inverse-excitation type diode, the colelctor electrode of a described NPN type triode is by the 17 resistance access power supply, its grounded emitter, its base stage connects the first pwm signal output pin of described microprocessor by the 18 resistance;
Described second switch comprises the 2nd NPN type triode and the 2nd P type metal-oxide-semiconductor, the drain electrode access load end of described the 2nd P type metal-oxide-semiconductor, its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of described the 2nd NPN type triode, between the source electrode of described the 2nd P type metal-oxide-semiconductor and drain electrode, cross-over connection has described the second inverse-excitation type diode, the colelctor electrode of described the 2nd NPN type triode is by the 19 resistance access power supply, its grounded emitter, its base stage is the second pwm signal output pin that resistance connects described microprocessor by second;
Described the 3rd switch comprises the first N-type metal-oxide-semiconductor, the drain electrode access load end of described the first N-type metal-oxide-semiconductor, its source electrode and substrate ground connection, its grid connects the first binary condition pin of described microprocessor by the 21 resistance, between the source electrode of described the first N-type metal-oxide-semiconductor and drain electrode, cross-over connection has described the 3rd inverse-excitation type diode;
Described the 4th switch comprises the second N-type metal-oxide-semiconductor, the drain electrode access load end of described the second N-type metal-oxide-semiconductor, its source electrode and substrate ground connection, its grid connects the second binary condition pin of described microprocessor by the 22 resistance, between the source electrode of described the second N-type metal-oxide-semiconductor and drain electrode, cross-over connection has described the 4th inverse-excitation type diode.
Open the first switch and the 4th switch drives forward current to open the door, open second switch and the 3rd switch drives reversing the current to close the door.Four described switches are driven and are controlled inductance average current by pulsewidth modulation (PWM) signal.The average current that can recently increase by heightening frequency range inductance, contrary, also can recently reduce average current by turning down frequency range.The set of frequency of PWM, at 250Hz, can allow described magnetic sensor measure current ripples so easily;
In the time of DM, must use the inverse-excitation type diode described in four, object is, in the time of PWM switch described in inverse-excitation type diode can clamp down on inductive drop and prevent current collapse.NPN type triode in described four switches can make the signal of a 0-5V carry out four metal-oxide-semiconductors of switch by the gate voltage of conversion 15V and 0V.
Further, described first, second, third, fourth inverse-excitation type diode is BYV26C type diode, and selecting BYV26C diode is the characteristic because of it with very low forward voltage and high-speed switch.
Described magnetic sensor mainly comprises an inductive current ripple detection circuit, described inductive current ripple detection circuit comprises the first amplifier and the second amplifier, the reverse input end of described the first amplifier connects the first resistance, the input in the same way of described the first amplifier is parallel with the second resistance and the 3rd resistance, the output of described the first amplifier has the 5th resistance of the 4th resistance and ground connection by the first Capacitance parallel connection, between the reverse input end of described the first amplifier and output, also cross-over connection has the 6th resistance; Described the first resistance connects high-pass filter, described the second resistance connects low pass filter by an inductance, the reverse input end of described the first amplifier and in the same way between input cross-over connection have the 7th, the 8th, the 9th resistance, described the 3rd resistance is by the second capacity earth, the two ends of described the second electric capacity are parallel with described the tenth resistance, and described the tenth resistance is by the 11 resistance eutral grounding;
The reverse input end of described the second amplifier connects the 12 resistance, the input in the same way of described the second amplifier is parallel with described the 4th resistance and the 3rd electric capacity, described the 3rd capacity earth, the output of described the second amplifier is by the 14 positive pole of resistance one general-purpose diode and the negative pole parallel connection of a Zener diode, and between the reverse input end of described the first amplifier and output, also cross-over connection has the 13 resistance; The plus earth of described Zener diode, the negative pole of described general-purpose diode is parallel with the 4th electric capacity of the 16 resistance and ground connection by the 15 resistance, and described the 16 resistance is connected with the ADC input pin of described microprocessor.
A very little detection resistance and an inductance series connection.Differential amplifier both end voltage is added in to detect on resistance provides a signal that is equivalent to inductive current.When described driving inductance is in the time that both direction drives, the bias voltage of a 2.5V is added in the two ends of differential amplifier, make the ripple signal can be measured, then this signal being exaggerated masks ripple by a high-pass filter, removes high-frequency noise by a low pass filter.
Then this signal being filtered is carried out rectification and is amplified this signal by a noninverting amplifier in the scope of 0-5V.A peak detector is used to set the DC DC voltage of a maximum ripple lower than 0.7V.Therefore the DC of this peak detector output has directly reflected inductance coefficent, and can be determined easily the state of door by microprocessor samples.By setting input pin to the very short time of 0V, this peak detector can be reset.
A described RC touch sensor comprises the 5th electric capacity, and one end of described the 5th electric capacity connects respectively the first input pin of described microprocessor and connects power supply, its other end ground connection by the 23 resistance.
A described RC touch sensor comprises the 6th electric capacity, and one end of described the 6th electric capacity connects respectively the second input pin of described microprocessor and connects power supply, its other end ground connection by the 24 resistance.
In the time that an electric capacity is connected to a power supply by a resistance, capacitance voltage will rise.Described the 5th, the 6th electric capacity is connected to first, second input pin of described microprocessor, described the 5th, the 6th electric capacity is just discharged into 0V.When described the 5th, the 6th capacitor charging is to supply voltage, described the 5th, the 6th capacitance voltage can be revealed, and then described first, second input pin is just switched to the state of a high impedance.Time used before described first, second input pin is identified as high voltage can measure with an inner timer, increase described the 5th, the 6th electric capacity will cause the increase in charging interval, therefore can carry out detecting touch by the variation of measuring the charging interval.
Compared with prior art, the utlity model has following beneficial effect:
The utility model is respectively by adopting flexible, efficient, a reliable door controller, one reliable, energy-conservation, one firmly and not needs the magnetic sensor of user's external calibration, one possesses the driving inductance of effectively power mechanism, and two tactile sensors that can prevent erroneous trigger and not need user's external calibration, built a high efficient and reliable practicality and refrigerator electromagnetic door control system cheaply, make user open refrigerator doors and become easier.Door controller is made a response to the request of two tactile sensors, and according to these requests, door controller is opened door with driving inductance, and last door controller is being opened or shut by judging refrigerator doors, closes driving inductance.
Above-mentioned explanation is only the general introduction of technical solutions of the utility model, in order to better understand technological means of the present utility model, and can be implemented according to the content of description, below with preferred embodiment of the present utility model and coordinate accompanying drawing to be described in detail as follows.Detailed description of the invention of the present utility model is provided in detail by following examples and accompanying drawing thereof.
Brief description of the drawings
Accompanying drawing described herein is used to provide further understanding of the present utility model, forms the application's a part, and schematic description and description of the present utility model is used for explaining the utility model, does not form improper restriction of the present utility model.In the accompanying drawings:
Fig. 1 is overall structure block diagram of the present utility model;
Fig. 2 is the electrical block diagram that the utility model drives inductance;
Fig. 3 is the circuit theory diagrams that the utility model drives inductance;
Fig. 4 is power output and the input power curve map that the utility model drives inductance;
Fig. 5 is the circuit theory schematic diagram of the utility model magnetic sensor;
Fig. 6 is in the time that electromagnet is driven by repercussion, electromagnetic field distribution schematic diagram;
Fig. 7 is when with pwm signal DM, the ripple schematic diagram of electric current;
Fig. 8 is the circuit theory schematic diagram of the utility model the one RC touch sensor;
Fig. 9 is the circuit theory schematic diagram of the utility model the 2nd RC touch sensor.
Detailed description of the invention
Below with reference to the accompanying drawings and in conjunction with the embodiments, describe the utility model in detail.
Shown in Figure 1, a kind of refrigerator electromagnetic door control system, comprise a door controller 1 taking microprocessor as core, described door controller 1 is connected with respectively one and drives inductance 2, magnetic sensor 3, a RC touch sensor 4 and the 2nd RC touch sensor 5.
Described microprocessor comprises the first pwm signal output pin PB1, the second pwm signal output pin PB2, the first binary condition pin PB3, the second binary condition pin PB4, ADC input pin PC0, the first input pin PD5 and the second input pin PD6.
Shown in Figure 2, described driving inductance 2 mainly comprises a H electric bridge, described H electric bridge comprises first, second, the 3rd, the 4th switch S 1, S2, S3, S4, described first, second, the 3rd, the 4th switch S 1, S2, S3, there is first of BYV26C type at the two ends of S4 respectively corresponding cross-over connection, second, the 3rd, the 4th inverse-excitation type diode D1, D2, D3, D4, described first, second switch S1, power supply is accessed respectively in one end of S2, the other end accesses respectively load end, the described the 3rd, the 4th switch S 3, load end is accessed respectively in one end of S4, the other end is ground connection respectively.
Open the first switch S 1 and the 4th switch S 4 drives forward current to open the door, open second switch S2 and the 3rd switch S 3 drives reversing the current to close the door.Four described switches are driven and are controlled inductance average current by pulsewidth modulation (PWM) signal.The average current that can recently increase by heightening frequency range inductance, contrary, also can recently reduce average current by turning down frequency range.The set of frequency of PWM, at 250Hz, can allow described magnetic sensor 3 measure current ripples so easily.
In the time of DM, must use the inverse-excitation type diode described in four, object is, in the time of PWM switch described in inverse-excitation type diode can clamp down on inductive drop and prevent current collapse.Selecting BYV26C diode is the characteristic because of it with very low forward voltage and high-speed switch.
Shown in Figure 3, described the first switch S 1 comprises a NPN type triode Q5 and a P type metal-oxide-semiconductor Q1, the drain electrode access load end of a described P type metal-oxide-semiconductor Q1, its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of a described NPN type triode Q5, between the source electrode of a described P type metal-oxide-semiconductor Q1 and drain electrode, cross-over connection has described the first inverse-excitation type diode D1, the colelctor electrode of a described NPN type triode Q5 accesses power supply by the 17 resistance R 17, its grounded emitter, its base stage connects the first pwm signal output pin PB1 of described microprocessor by the 18 resistance R 18,
Described second switch S2 comprises the 2nd NPN type triode Q6 and the 2nd P type metal-oxide-semiconductor Q2, the drain electrode access load end of described the 2nd P type metal-oxide-semiconductor Q2, its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of described the 2nd NPN type triode Q6, between the source electrode of described the 2nd P type metal-oxide-semiconductor Q2 and drain electrode, cross-over connection has described the second inverse-excitation type diode D2, the colelctor electrode of described the 2nd NPN type triode Q6 accesses power supply by the 19 resistance R 19, its grounded emitter, its base stage is the second pwm signal output pin PB2 that resistance R 20 connects described microprocessor by second,
Described the 3rd switch S 3 comprises the first N-type metal-oxide-semiconductor Q3, the drain electrode access load end of described the first N-type metal-oxide-semiconductor Q3, its source electrode and substrate ground connection, its grid connects the first binary condition pin PB3 of described microprocessor by the 21 resistance R 21, between the source electrode of described the first N-type metal-oxide-semiconductor Q3 and drain electrode, cross-over connection has described the 3rd inverse-excitation type diode D3;
Described the 4th switch S 4 comprises the second N-type metal-oxide-semiconductor Q4, the drain electrode access load end of described the second N-type metal-oxide-semiconductor Q4, its source electrode and substrate ground connection, its grid connects the second binary condition pin (PB4) of described microprocessor by the 22 resistance R 22, between the source electrode of described the second N-type metal-oxide-semiconductor Q4 and drain electrode, cross-over connection has described the 4th inverse-excitation type diode D4.
NPN type triode in four described switches can make the signal of a 0-5V carry out four metal-oxide-semiconductors of switch by the gate voltage of conversion 15V and 0V.Metal-oxide-semiconductor is selected STP12PF06(P type) and STP16NF06L(N type), the advantage of selecting this metal-oxide-semiconductor is in electric current their efficiency very high (Rds<0.2 Ω) during lower than 5A.Power output and the input power of driving inductance of the present utility model are shown in Figure 4, in figure, clearly can find out driving inductance of the present utility model because of adopt metal-oxide-semiconductor, can export larger power, efficiency is higher.
Shown in Figure 5, described magnetic sensor 3 mainly comprises an inductive current ripple detection circuit, described inductive current ripple detection circuit comprises the first amplifier U1 and the second amplifier U2, the reverse input end of described the first amplifier U1 connects the first resistance R 1, the input in the same way of described the first amplifier U1 is parallel with the second resistance R 2 and the 3rd resistance R 3, the output of described the first amplifier U1 is parallel with the 5th resistance R 5 of the 4th resistance R 4 and ground connection by the first capacitor C 1, between the reverse input end of described the first amplifier U1 and output, also cross-over connection has the 6th resistance R 6, described the first resistance R 1 connects high-pass filter LH, described the second resistance R 2 connects low pass filter LP by an inductance L, the reverse input end of described the first amplifier U1 and in the same way between input cross-over connection have the 7th, the 8th, the 9th resistance R 7, R8, R9, described the 3rd resistance R 3 is by the second capacitor C 2 ground connection, and the two ends of described the second capacitor C 2 are parallel with described the tenth resistance R 10, and described the tenth resistance R 10 is by the 11 resistance R 11 ground connection,
The reverse input end of described the second amplifier U2 connects the 12 resistance R 12, the input in the same way of described the second amplifier U2 is parallel with described the 4th resistance R 4 and the 3rd capacitor C 3, described the 3rd capacitor C 3 ground connection, the output of described the second amplifier U2 is by the positive pole of the 14 resistance R 14 1 general-purpose diode D5 and the negative pole parallel connection of a Zener diode D6, and between the reverse input end of described the first amplifier U1 and output, also cross-over connection has the 13 resistance R 13; The plus earth of described Zener diode D6, the negative pole of described general-purpose diode D5 is parallel with the 4th capacitor C 4 of the 16 resistance R 16 and ground connection by the 15 resistance R 15, and described the 16 resistance R 16 is connected with the ADC input pin PC0 of described microprocessor.
Induction coefficient theory
Be arranged on the permanent magnet in refrigerator doors and be arranged on distance between the electromagnet of inside refrigerator door and inductance that refrigerator electromagnetic door magnetic sensor of the present utility model records has direct relation.According to Faraday's law, measured induction coefficient of electromagnet is that magnetic flux all directly and in electromagnetic circuit is proportional.When supposing the system is linear, this law is correct.If electromagnet opposite direction drives, inductance just reduces, and the just close electromagnet of permanent magnet, and this impact can be used to measure the state of door.
For the door that turns a refrigerator off, in the time driving inductance H electric bridge to be reversed driving, electromagnetic field distributes shown in Figure 6.In the time that alnico magnets are shifted to electromagnet, the interaction between magnetic field can change the total magnetic flux in circuit.Near magnetic flux magnet is because the negative function in magnetic field will reduce.Magnetic flux between electromagnet and alnico magnets is because the increase in the magnetic field that magnet produces will be risen.
Because be the strongest near the magnetic field at the two poles of the earth places, and the increase of electromagnet internal magnetic flux compares, and between magnet, the counteracting in magnetic field can cause its magnetic flux sharply to reduce pro rata.So final magnetic flux reduces.Thereby the inductance recording also reduces.
RL method time response
A method measuring electromagnet inductance is similar with measuring electric capacity.When on the resistance of making alive in an inductance and series connection, the growth rate of electric current depends on inductance coefficent.Current rise to an one needed time of certain value can be measured, and also can measure the state of door.
The detection method of current ripples
In the time driving an electromagnet with a pwm signal, the ripple type that electric current shows is shown in Figure 7.The ripple of electric current and the inductance coefficent of coil and operating frequency have direct relation.The increase of inductance coefficent or frequency can cause very little current ripples, and vice versa.Select the PWM frequency of 250Hz to improve the amplitude of current ripples.
The circuit theory of described magnetic sensor is shown in Figure 5, a very little detection resistance and an inductance series connection.Differential amplifier both end voltage is added in to detect on resistance provides a signal that is equivalent to inductive current.When H electric bridge is in the time that both direction drives, the bias voltage of a 2.5V is added in the two ends of differential amplifier, makes the ripple signal can be measured.Then this signal being exaggerated masks ripple by a high-pass filter, removes high-frequency noise by a low pass filter.
Then this signal being filtered is carried out rectification and is amplified this signal by a noninverting amplifier in the scope of 0-5V.A peak detector is used to set the DC DC voltage of a maximum ripple lower than 0.7V.Therefore the DC of this peak detector output has directly reflected inductance coefficent, and can be determined easily the state of door by described microprocessor samples.By setting input pin to the very short time of 0V, this peak detector can be reset.
Shown in Figure 8, a described RC touch sensor 4 comprises the 5th capacitor C 5, and one end of described the 5th capacitor C 5 connects respectively the first input pin PD5 of described microprocessor and connects power supply by the 23 resistance R 23, its other end ground connection;
Shown in Figure 9, a described RC touch sensor 5 comprises the 6th capacitor C 6, and one end of described the 6th capacitor C 6 connects respectively the second input pin PD6 of described microprocessor and connects power supply by the 24 resistance R 24, its other end ground connection.
In the time that an electric capacity is connected to a power supply by a resistance, capacitance voltage will rise.Described the 5th, the 6th capacitor C 5, C6 is connected to first, second input pin PD5 of described microprocessor, PD6, and described the 5th, the 6th capacitor C 5, C6 is just discharged into 0V.When described the 5th, the 6th capacitor C 5, C6 is charged to supply voltage, described the 5th, the 6th capacitor C 5,, C6 voltage can be revealed, then described first, second input pin PD5, and PD6 is just switched to the state of a high impedance.At described first, second input pin PD5, before PD6 is identified as high voltage, the time used can measure with an inner timer, described the 5th, the 6th capacitor C 5, the increase of C6 will cause the increase in charging interval, therefore can carry out detecting touch by the variation of measuring the charging interval.
2 input pins on described microprocessor are used for controlling the operation of 2 described RC touch sensors.In order to ensure the accurate reading of described RC touch sensor, the operating frequency of described microprocessor is 8MHz.The simultaneously operating of 2 described touch sensors can be by completing by the internal interrupt on described microprocessor.Touch when detecting one, corresponding interrupt line is just provided and Interrupt Service Routine (ISR) is just activated, by guaranteeing the shorter synchronism of effectively simulating of Length Ratio of ISRs.
Operating process of the present utility model is as follows:
The implementation Process of the utility model switch refrigerator doors similar finite state machine (FSM) that gets up.The advantage of using FSM is that the operational order of door only could be carried out in the specific clock interval of internal clocking interruption generation.The remaining time, CPU can be used for disconnecting the link of 2 touch sensors.The advantage of this utilization is that system can reactivate completely with synchronously.
Identified when a touch, this program starts to activate FSM and the state of inspection door for the first time.The state of inspection door completes by three steps.Set direction and the duty factor of H electric bridge, and reset peak detector.Then be to produce a time delay peak detector is fixed.It is finally the state of reading the reading of peak detector and determining door.
If the state of initial door is closing while being detected, the electric current in H electric bridge just increases to a specific maximum.The duty factor at every turn using by increasing FSM while increasing electric current.Once after this process completes, the state of door can be checked again.If door is not opened H electric bridge so and is just closed.If door has been opened, the state of door can be continued to detect.If door does not shut away in official hour, can attempt closing the door by the electric current in increase inductance slowly.If this is attempted unsuccessfully, controller is by the state of endless readout gate.If door is successfully shut, H electric bridge is just closed so.
Being calculated as follows of all device value of the present utility model:
1, amplifier gain
The size of input voltage ripple--H electric bridge drives in the time of 40% duty-cycle--records about 60mV.The gain of design operation amplifier circuit reaches the final about 4V of output, and this is just in time in the scope of ADC input voltage.
Because ripple signal has been rectified, this effective input signal only has 30mV.Therefore the gain of differential amplifier and noninverting amplifier is:
；
Therefore the gain of differential amplifier elects 8 as, and the gain of noninverting amplifier is made as 16, and total gain is 128.
Correct differential operational amplifier must meet:
；
Therefore the gain of differential amplifier is:
；
R12 and R2 elect 100K as and ensure that with this differential amplifier has very high input impedance (200K).Two resistance must ensure that very greatly common mode current is very little.Obtain R3=R6=8 × 100 K Ω 820 K Ω from above formula.
The gain of noninverting amplifier is:
；
Therefore, for the gain 16 that obtains expecting, R13=820 K Ω and R12=56 K Ω.
2, divider
When driving inductance H electric bridge in the time that both direction drives, differential amplifier needs a 2.5VDC bias voltage to survey ripple.This DC is got by the supply voltage of 15V:
；
；
；
；
Let?
?
。
3, wave filter
The angular frequency of high-pass filter is chosen in 25Hz.This is under being still retained when under PWM frequency, 101 decay and the main information of this signal are removing DC part.The formula of angular frequency is as follows:
；
Let?
。
The angular frequency of low pass filter is chosen in 2.5KHz--more than 10 octaves of frequency-of-interest (10
1).The formula of low pass filter is with the same above.R5 selects 68K to ensure can not be written into previous stage wave filter, therefore selects 10nF according to above formula C1.
4, Zener diode
Select the Zener diode of 5.1V to limit the output voltage of noninverting amplifier.By guaranteeing that voltage can not exceed 5.5V and come the ADC pin of the microprocessor of shutter controller.The resistance of a 10K is placed between the output of operational amplifier and Zener diode and limits from operational amplifier maximum current out.
5, crest detector
Selecting 1N4148 diode to be used as crest detector uses.In the time selecting the value of crest detector capacitor C 4, must make compromise selects.Large electric capacity has stable voltage.But large electric capacity also can cause the input of crest detector to change slowly.The value of this capacitor C 4 is selected 15nF after consideration.
The maximum current of setting inflow C4 is 50mA,
。
The maximum input voltage of crest detector is exactly that the maximum output voltage of noninverting amplifier deducts the voltage on general-purpose diode D1.After crest detector is resetted again, the ADC pin of the microprocessor of door controller is just reset to 0V and electric current flows into pin from C4.Current settings is at 15mA, little more a lot of than maximum rated current 40mA;
。
6, the first switch S 1 and second switch S2
By first, second resistance R 1, the ideal current of R2 is set in 1.2mA;
。
First, second NPN triode Q5, the minimum hfe of Q6 is 200, selects overdrive factor 3 to ensure first, second NPN triode Q5, Q6 normal switch.
；
。
When input signal is at 5V time, in order to ensure that 18 μ A electric currents enter first, second NPN triode Q5, the base stage of Q6, second, the 4th resistance R 2, R4 selects as follows:
；
Because overdrive factor 3 is relatively stable, resistance value can be got an approximation.
7, the 3rd switch S 3 and the 4th switch S 4
When the metal-oxide-semiconductor of the 3rd switch S 3 and the 4th switch S 4 is on off state, the 5th, the 6th resistance R 5, R6 selects 12k to limit the electric current between H electric bridge and microprocessor.
8, inverse-excitation type diode
Selecting BYV26C diode is because it has low forward voltage and high-speed switch effect.
9, RC touch sensor
Because described microprocessor work is under the clock frequency of 8MHz, the counter of 8 needed time of overflowing is 32 μ s.A pin of described microprocessor identification is that 2.5V is to 5V in the probable ranges of high level.
Capacitor charging, to 5V, therefore reaches 2.5V probably as long as a time constant.When RC touch sensor is in the time testing, the time constant of circuit is set in 10 μ s and guarantees that timer can not overflow.
The maximum leakage current of described microprocessor discrepancy pin is 1 μ A.Therefore the input pin that, the resistance of selection 100k is guaranteed described microprocessor is still under " high impedance " state.Being calculated as follows of capacitance:
;
;
。
The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various modifications and variations.All within spirit of the present utility model and principle, any amendment of doing, be equal to replacement, improvement etc., within all should being included in protection domain of the present utility model.
Claims (2)
1. a refrigerator electromagnetic door control system, it is characterized in that: comprise a door controller (1) taking microprocessor as core, described door controller (1) is connected with respectively one and drives inductance (2), magnetic sensor (3), a RC touch sensor (4) and the 2nd RC touch sensor (5);
Described microprocessor comprises the first pwm signal output pin (PB1), the second pwm signal output pin (PB2), the first binary condition pin (PB3), the second binary condition pin (PB4), ADC input pin (PC0), the first input pin (PD5) and the second input pin (PD6);
Described driving inductance (2) mainly comprises a H electric bridge, described H electric bridge comprises first, second, the 3rd, the 4th switch (S1, S2, S3, S4), described first, second, the 3rd, the 4th switch (S1, S2, S3, S4) two ends respectively corresponding cross-over connection have first, second, the 3rd, the 4th inverse-excitation type diode (D1, D2, D3, D4), described first, second switch (S1, S2) power supply is accessed respectively in one end, the other end accesses respectively load end, the described the 3rd, the 4th switch (S3, S4) load end is accessed respectively in one end, the other end is ground connection respectively,
Described the first switch (S1) comprises a NPN type triode (Q5) and a P type metal-oxide-semiconductor (Q1), the drain electrode access load end of a described P type metal-oxide-semiconductor (Q1), its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of a described NPN type triode (Q5), between the source electrode of a described P type metal-oxide-semiconductor (Q1) and drain electrode, cross-over connection has described the first inverse-excitation type diode (D1), the colelctor electrode of a described NPN type triode (Q5) is by the 17 resistance (R17) access power supply, its grounded emitter, its base stage connects the first pwm signal output pin (PB1) of described microprocessor by the 18 resistance (R18),
Described second switch (S2) comprises the 2nd NPN type triode (Q6) and the 2nd P type metal-oxide-semiconductor (Q2), the drain electrode access load end of described the 2nd P type metal-oxide-semiconductor (Q2), its source electrode and substrate access power supply, its grid is connected with the colelctor electrode of described the 2nd NPN type triode (Q6), between the source electrode of described the 2nd P type metal-oxide-semiconductor (Q2) and drain electrode, cross-over connection has described the second inverse-excitation type diode (D2), the colelctor electrode of described the 2nd NPN type triode (Q6) is by the 19 resistance (R19) access power supply, its grounded emitter, its base stage is the second pwm signal output pin (PB2) that resistance (R20) connects described microprocessor by second,
Described the 3rd switch (S3) comprises the first N-type metal-oxide-semiconductor (Q3), the drain electrode access load end of described the first N-type metal-oxide-semiconductor (Q3), its source electrode and substrate ground connection, its grid connects the first binary condition pin (PB3) of described microprocessor by the 21 resistance (R21), between the source electrode of described the first N-type metal-oxide-semiconductor (Q3) and drain electrode, cross-over connection has described the 3rd inverse-excitation type diode (D3);
Described the 4th switch (S4) comprises the second N-type metal-oxide-semiconductor (Q4), the drain electrode access load end of described the second N-type metal-oxide-semiconductor (Q4), its source electrode and substrate ground connection, its grid connects the second binary condition pin (PB4) of described microprocessor by the 22 resistance (R22), between the source electrode of described the second N-type metal-oxide-semiconductor (Q4) and drain electrode, cross-over connection has described the 4th inverse-excitation type diode (D4);
Described magnetic sensor (3) mainly comprises an inductive current ripple detection circuit, described inductive current ripple detection circuit comprises the first amplifier (U1) and the second amplifier (U2), the reverse input end of described the first amplifier (U1) connects the first resistance (R1), the input in the same way of described the first amplifier (U1) is parallel with the second resistance (R2) and the 3rd resistance (R3), the output of described the first amplifier (U1) is parallel with the 5th resistance (R5) of the 4th resistance (R4) and ground connection by the first electric capacity (C1), between the reverse input end of described the first amplifier (U1) and output, also cross-over connection has the 6th resistance (R6), described the first resistance (R1) connects high-pass filter (LH), described the second resistance (R2) connects low pass filter (LP) by an inductance (L), the reverse input end of described the first amplifier (U1) and in the same way between input cross-over connection have the 7th, the 8th, the 9th resistance (R7, R8, R9), described the 3rd resistance (R3) is by the second electric capacity (C2) ground connection, the two ends of described the second electric capacity (C2) are parallel with described the tenth resistance (R10), and described the tenth resistance (R10) is by the 11 resistance (R11) ground connection,
The reverse input end of described the second amplifier (U2) connects the 12 resistance (R12), the input in the same way of described the second amplifier (U2) is parallel with described the 4th resistance (R4) and the 3rd electric capacity (C3), described the 3rd electric capacity (C3) ground connection, the output of described the second amplifier (U2) is by the positive pole of the 14 resistance (R14) general-purpose diode (D5) and the negative pole parallel connection of a Zener diode (D6), and between the reverse input end of described the first amplifier (U1) and output, also cross-over connection has the 13 resistance (R13); The plus earth of described Zener diode (D6), the negative pole of described general-purpose diode (D5) is parallel with the 4th electric capacity (C4) of the 16 resistance (R16) and ground connection by the 15 resistance (R15), described the 16 resistance (R16) is connected with the ADC input pin (PC0) of described microprocessor;
A described RC touch sensor (4) comprises the 5th electric capacity (C5), one end of described the 5th electric capacity (C5) connects respectively first input pin (PD5) of described microprocessor and connects power supply, its other end ground connection by the 23 resistance (R23);
A described RC touch sensor (5) comprises the 6th electric capacity (C6), one end of described the 6th electric capacity (C6) connects respectively second input pin (PD6) of described microprocessor and connects power supply, its other end ground connection by the 24 resistance (R24).
2. refrigerator electromagnetic door according to claim 1 drives inductance, it is characterized in that: described first, second, third, fourth inverse-excitation type diode (D1, D2, D3, D4) is BYV26C type diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420279527.8U CN203869417U (en) | 2014-05-28 | 2014-05-28 | Electromagnetic door control system for refrigerator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420279527.8U CN203869417U (en) | 2014-05-28 | 2014-05-28 | Electromagnetic door control system for refrigerator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203869417U true CN203869417U (en) | 2014-10-08 |
Family
ID=51650360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420279527.8U Withdrawn - After Issue CN203869417U (en) | 2014-05-28 | 2014-05-28 | Electromagnetic door control system for refrigerator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203869417U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103968638A (en) * | 2014-05-28 | 2014-08-06 | 苏州工业职业技术学院 | Refrigerator electromagnetic door control system |
| WO2017206267A1 (en) * | 2016-05-30 | 2017-12-07 | 北京小米移动软件有限公司 | Door frame assembly applied to microwave oven, and method and device for controlling door frame assembly |
-
2014
- 2014-05-28 CN CN201420279527.8U patent/CN203869417U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103968638A (en) * | 2014-05-28 | 2014-08-06 | 苏州工业职业技术学院 | Refrigerator electromagnetic door control system |
| CN103968638B (en) * | 2014-05-28 | 2016-02-17 | 苏州工业职业技术学院 | A kind of refrigerator electromagnetic door control system |
| WO2017206267A1 (en) * | 2016-05-30 | 2017-12-07 | 北京小米移动软件有限公司 | Door frame assembly applied to microwave oven, and method and device for controlling door frame assembly |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103760408B (en) | Zero cross detection circuit | |
| CN102832792A (en) | Source electrode driving control circuit and control method thereof | |
| CN202929095U (en) | AC over-current detection device | |
| CN104767173B (en) | Ground wire voltage exception earth leakage protective device is detected without IC optocouplers | |
| CN108519505A (en) | A kind of residual current detection device and method of the PWM way of outputs | |
| CN105992435A (en) | Anti-interference LED overvoltage protection module and anti-interference LED overvoltage protection system | |
| CN203869417U (en) | Electromagnetic door control system for refrigerator | |
| CN106597075A (en) | Alternating voltage detection device and method | |
| CN103968638B (en) | A kind of refrigerator electromagnetic door control system | |
| CN202548267U (en) | Circuit for detecting live wire and zero wire | |
| CN104833929A (en) | Transformer demagnetization analyzer | |
| CN210807121U (en) | Counter electromotive force zero-crossing detection circuit | |
| CN205212219U (en) | Switch board with warning function of closing door | |
| CN107994636A (en) | A kind of roadside advertising film accumulator charging and discharging state detection device | |
| CN209017007U (en) | Alternating current zero crossing triggering type relay | |
| CN207664904U (en) | A kind of circuit for stablizing brush motor rotary speed | |
| CN202661537U (en) | Lightning surge sensor using reed pipe | |
| CN204556807U (en) | A kind of transformer demagnetization analyzer | |
| CN206610253U (en) | A kind of display screen intelligent controlling device based on server system | |
| CN203870270U (en) | Refrigerator electromagnetic door magnetic sensor | |
| CN101738526B (en) | Direct current output voltage test circuit for power factor correction control circuit | |
| CN203457043U (en) | Interactive PFC boost topology circuit | |
| CN209088589U (en) | Charging high-temperature protection circuit and cooker | |
| CN208984778U (en) | A kind of low current motor open-circuit condition detection circuit and household electrical appliance | |
| CN207832988U (en) | A kind of Three phase power phase shortage reverse phase detection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20141008 Effective date of abandoning: 20160217 |
|
| C25 | Abandonment of patent right or utility model to avoid double patenting |