Air valve analog quantity feedback control circuit

Abstract

The utility model provides an air valve analog quantity feedback control circuit, and relates to the technical field of air valve adjustment. The circuit comprises a signal following block, a differential amplification output block and a same-reverse comparison output block which are connected in sequence and are respectively connected to a power supply module; the power supply module comprises a rectification circuit and a switching power supply. The signal following block is connected to a potentiometer on the air valve and is used for receiving and transmitting a feedback signal; the same-reverse comparison output block is connected to the air valve and used for controlling opening and closing of the air valve. According to the control circuit, a mechanical structure is replaced by a circuit structure, the fault rate is low, and the effective service life is long. Furthermore, the circuit board etched based on the feedback control circuit is convenient to install, later troubleshooting and adjustment are facilitated, and the maintenance efficiency and the operation efficiency of the ventilation system can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of wind valve analog quantity feedback control circuits. BACKGROUND

[0002] To protect the air quality in large closed building space, a large number of electrically adjusted air valves are used in stations, parking lots and other places. Electrically adjusted air valves are installed on the air pipes of air conditioning and ventilation systems to regulate the air volume of branch pipes or to mix fresh air and return air. Electrically adjusted air valves use electrically operated on-off valves to output on-off electrical signals and feedback the opening angle of the air valve. The opening angle of the air valve is fed back to the electric control end using a gear. In the field of air valve regulation technology, the mechanical feedback method has a high failure rate after the air valve has been used for several years. The complex mechanical structure makes it difficult to adjust and the debugging method is difficult to master, which has many disadvantages such as inconvenient installation and fault finding. Furthermore, due to the special mechanical structure of the gear, it often needs to be customized after damage, which increases the difficulty and cost of maintenance and reduces the efficiency of maintenance. In addition, the mechanical fault is not easy to adjust because the air valve is usually installed in a small space.

[0003] In summary, the mechanical structure used in the existing mechanical feedback method is complex, has a high failure rate, and has a short effective service life. Furthermore, there are problems such as inconvenient installation, low maintenance efficiency, and high difficulty in fault finding and adjustment in the later stage. SUMMARY

[0004] To solve the above technical problems in the prior art, the utility model provides a kind of wind valve analog quantity feedback control circuits.

[0005] Specifically, a kind of wind valve analog quantity feedback control circuits includes signal following block, difference amplification output block and same-reverse comparison output block connected in sequence;

[0006] The signal following block is connected to the potentiometer on the air valve for receiving the feedback signal output by the potentiometer. The potentiometer is connected to the upper computer, and the upper computer outputs a control signal to adjust the resistance of the potentiometer.

[0007] The difference amplification output block is used to convert the current of the output signal of the signal follower into an analog quantity and output it.

[0008] The output end of the same-reverse comparison output block is connected to the air valve for controlling the opening and closing of the air valve according to the comparison result of the voltage of the analog quantity and the threshold voltage.

[0009] Preferably, the difference amplification output block includes:

[0010] In the operational amplifier Y2, the negative input pin is connected to the output of the signal following block and to the emitter of the PNP transistor Q1 through the resistor R2; the positive input pin is connected to the zero setting potentiometer; one end of the zero setting potentiometer is connected to the output of the switching power supply through the resistor R6 and the other end is connected to the ground through the resistor R7; the output pin is connected to the negative input pin through the capacitor R5 and to the base of the transistor Q1 through the resistor R4;

[0011] In the transistor Q1, the emitter is connected to the power supply through the resistor R1 and the terminal setting potentiometer in sequence; the collector is connected to the anode of the diode D1 and to the ground through the capacitor C7;

[0012] The anode of the diode D1 is connected to the positive pole of the polarized capacitor C6 and the cathode is connected to the positive pin of the analog quantity feedback end; the negative pole of the polarized capacitor C6 is connected to the ground.

[0013] Preferably, the same-reverse comparison output block comprises:

[0014] The negative input pin of the same-direction operational amplifier Y3 is connected to the negative pin of the analog quantity feedback end through the resistor R15 and to the positive pole of the polarized capacitor C9; the negative pole of the polarized capacitor C9 is connected to the ground and to the negative pin of the analog quantity feedback end through the resistor R16;

[0015] In the same-direction operational amplifier Y3, the positive power supply pin is connected to the ground, the negative power supply pin is connected to the power supply, and the capacitor C8 is arranged between the positive power supply pin and the negative power supply pin; the positive input pin is connected to the sliding end of the full-off adjusting potentiometer P1 through the resistor R9 and to the power supply through the resistor R9, the resistor R8 and the resistor R5 in sequence; the resistor R10 is arranged between the positive input pin and the output pin; the output pin is connected to the base of the NPN transistor Q2 through the resistor R13;

[0016] One end of the full-off adjusting potentiometer P1 is connected to the power supply through the resistor R5 and to the ground through the resistor R8 and the resistor R11 in sequence, and the other end is connected to the ground;

[0017] In the transistor Q2, the collector is connected to the cathode of the photoresistor D3 and to the anode of the diode D2 through the resistor R12; the emitter is connected to the ground and to the base through the resistor R14;

[0018] The anode of the photoresistor D3 and the cathode of the resistor D2 are both connected to the power supply; the resistor D2 is connected in parallel with the first relay; one end of the output loop of the first relay is connected to the switching to position common end FCOM pin and the other end is connected to the switching to position feedback end FQG pin;

[0019] The negative input pin of the same-direction operational amplifier Y3 is connected to the positive input pin of the reverse-direction operational amplifier Y4 in the same-reverse comparison output block through the resistor R22;

[0020] In the inverting operational amplifier Y4, the positive input pin is connected to the output pin through the resistor R18 and the resistor R19 in turn, and is grounded through the resistor R18 and the resistor R19 in turn; the negative input pin is connected to the sliding end of the full-on regulating potentiometer P2; the output pin is connected to the base of the NPN triode Q3 through the resistor R213;

[0021] One end of the full-on regulating potentiometer P2 is connected to the power supply through the resistor R29, and is connected to the negative input pin of the inverting operational amplifier Y4 through the resistor R27; the other end of the full-on regulating potentiometer P2 is grounded through the resistor R28, and is connected to the negative input pin of the inverting operational amplifier Y4 through the resistor R26;

[0022] In the triode Q3, the collector is connected to the cathode of the light emitting diode D5 and the anode of the diode D4 through the resistor R20; the emitter is grounded, and is connected to the base through the resistor R25;

[0023] The anode of the light emitting diode D5 and the cathode of the diode D4 are both connected to the power supply; the diode D4 is connected in parallel with the second relay; one end of the output loop of the second relay is connected to the switch-to-position common end FCOM pin, and the other end is connected to the open-to-position feedback end FQK pin;

[0024] The positive pin and the negative pin of the analog quantity feedback end, the switch-to-position common end FCOM pin, the close-to-position feedback end FQG pin, and the open-to-position feedback end FQK pin are all arranged on the connector J2; the connector J2 further includes the NN pin connected to the zero line, and the L pin, the open-to-position L1 pin, and the close-to-position L2 pin connected to the fire line through the same end point.

[0025] Further, the power supply module is further included for supplying power to the signal following block, the differential amplification output block, and the same-inverted comparison output block.

[0026] Preferably, the power supply module includes a rectifier circuit; the rectifier circuit includes the fuse F1, the voltage-dependent resistor RZ1, the capacitor CX1, the thermistor NTC1, the common-mode inductor LX1, the rectifier bridge DB1, the direct current inductor LX2, the first electrolytic capacitor E1, and the second electrolytic capacitor E2;

[0027] The L pin of the first connector is connected to one pin of the input end of the first common-mode inductor LX1 through the fuse F1, and the NN pin is connected to the other pin of the input end of the common-mode inductor LX1 through the thermistor NTC1;

[0028] One end of the voltage-dependent resistor RZ1 is connected to one pin of the input end of the common-mode inductor LX1, and the other end is connected to the other pin of the input end of the common-mode inductor LX1;

[0029] The capacitor CX1 is connected in parallel with the thermistor NTC1;

[0030] Two feet of the common mode inductance LX1 output end are connected to two feet of the rectifier bridge DB1 input end respectively;

[0031] One foot of the rectifier bridge DB1 output end is connected to the positive pole of the second electrolytic capacitor E2 through the direct current inductance LX2, and the other foot is connected to the negative pole of the second electrolytic capacitor E2;

[0032] The negative poles of the first electrolytic capacitor E1 and the second electrolytic capacitor E2 are connected to each other and grounded, and the positive poles are connected through the direct current inductance;

[0033] The positive pole of the second electrolytic capacitor E2 is the voltage output end.

[0034] Preferably, the power supply module comprises a switching power supply, and the switching power supply is a single-ended back-attack type switching power supply.

[0035] Preferably, the single-ended back-attack type switching power supply comprises a first RC absorption circuit.

[0036] The first RC absorption circuit comprises a capacitor CA1 and resistors RA3, RA4 and RA5, which are connected in parallel to each other.

[0037] One end of the first RC absorption circuit is connected to the output end of the rectifier circuit, the other end is connected to the cathode of a diode DA1, and is connected to the same end of a primary coil of a transformer T1 through the diode DA1.

[0038] Preferably, the single-ended back-attack type switching power supply comprises a second RC absorption circuit.

[0039] The second RC absorption circuit is connected in parallel to a diode DA4 and comprises a capacitor CA4, a resistor RA12 and a resistor RA13.

[0040] One end of the capacitor CA4 is connected to the same end of a secondary coil of the transformer T1, and the other end is connected to the cathode of the diode DA4 through the resistor RA12; the resistor RA13 is connected in parallel to the resistor RA12.

[0041] Preferably, the single-ended back-attack type switching power supply comprises a capacitor CA5.

[0042] One end of the capacitor CA5 is connected to the different end of a second coil of the primary coil of the transformer T1 and grounded, and the other end is connected to the different end of the secondary coil of the transformer T1 and grounded.

[0043] It is obvious that the air valve analog quantity feedback control circuit directly connects the potentiometer on the air valve through the signal follower, so that the circuit feedback replaces the mechanical feedback, so that the failure rate of the air valve control device is reduced and has a long effective service life. Further, the circuit board etched by the feedback control circuit is convenient to install, and is convenient for troubleshooting and adjustment in the later period, which is beneficial to improve the maintenance efficiency and the operation efficiency of the ventilation system. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 A brief structure diagram of the wind valve analog quantity feedback control circuit in an embodiment of the present application.

[0045] Figure 2 A topology structure diagram of the power module rectifier circuit in an embodiment of the present application.

[0046] Figure 3 A topology structure diagram of the single-ended flyback switching power supply in an embodiment of the present application.

[0047] Figure 4 The EMC test (Electromagnetic Compatibility) result of the power module in an embodiment of the present application.

[0048] Figure 5 A topology structure diagram of the signal following block in an embodiment of the present application.

[0049] Figure 6 A topology structure diagram of the differential amplification output block in an embodiment of the present application.

[0050] Figure 7 A topology structure diagram of the same-anti-comparison output block in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In the following, the technical solutions provided by the present application will be further described in detail in combination with embodiments and drawings.

[0052] Embodiment 1

[0053] In this embodiment, according to the situation of the air regulating valve of a certain city subway, it is found that the traditional air valve is prone to mechanical fatigue, the gear and cam error will increase, the positioning needs to be frequently adjusted, and the power supply part is prone to electromagnetic interference and other problems that need to be solved. After analyzing the current situation, the following method is used to solve it: based on the operational amplifier circuit, the analog circuit is divided into four blocks: power module, signal following block, differential amplification output block, and same-anti-comparison output block.

[0054] As Figure 1As shown, the "power module" converts the AC 220 power supply into a stable DC 24V power supply, which powers the "signal following block", "differential amplification output block" and "same-reverse comparison output block". The regulated control signal enters the "signal following block", which converts it into a stable regulated signal, which is further amplified in the "differential amplification output block" and then enters the "same-reverse comparison output block", which controls the valve according to the comparison threshold of "full open" and "full close". The signal follower is connected to the potentiometer on the host computer and the air valve, and is used to receive the control signal output by the host computer and the feedback signal output by the potentiometer. The differential amplification output block is used to convert the current of the output signal of the signal follower into a 4-20mA analog quantity and output it. The output end of the same-reverse comparison output block is connected to the air valve, which is used to control the opening and closing of the air valve according to the comparison result of the voltage of the 4-20mA analog quantity and the threshold voltage. Among them, the 4-20mA analog quantity can be replaced by a 0-20mA analog quantity, or other appropriate range analog quantity.

[0055] The quality of the power supply directly affects the performance of the circuit. A poor power supply can introduce voltage fluctuations and noise, especially electromagnetic compatibility, common-mode interference and other related problems, and is easily disturbed by other devices or power lines, increasing measurement error.

[0056] As shown in Figure 2 The "rectifier circuit" in the power module is shown. In the rectifier circuit, a CX1 capacitor is added to filter out differential mode interference signals. A common mode inductor LX1 is added to the AC input to filter out common mode interference signals. A DC inductor LX2 is added at the rectified DC voltage (about 310V) to reduce voltage fluctuations and electromagnetic interference by connecting two energy storage capacitors in series.

[0057] Specifically, the power module includes a rectifier circuit and a switching power supply;

[0058] The rectifier circuit includes a first connector, a fuse F1, a pressure-sensitive resistor RZ1, a capacitor CX1, a thermistor NTC1, a common mode inductor LX1, a rectifier bridge DB1, a DC inductor LX2, a first electrolytic capacitor E1 and a second electrolytic capacitor E2;

[0059] The L pin of the first connector is connected to one pin of the input end of the first common mode inductor LX1 through the fuse F1, and the NN pin is connected to the other pin of the input end of the common mode inductor LX1 through the thermistor NTC1;

[0060] One end of the pressure-sensitive resistor RZ1 is connected to one pin of the input end of the common mode inductor LX1, and the other end is connected to the other pin of the input end of the common mode inductor LX1;

[0061] The capacitor CX1 is connected in parallel with the thermistor NTC1;

[0062] The two pins of the common mode inductor LX1 output end are connected to the two pins of the rectifier bridge DB1 input end respectively;

[0063] One pin of the rectifier bridge DB1 output end is connected to the positive pole of the second electrolytic capacitor E2 through the direct current inductor LX2, and the other pin is connected to the negative pole of the second electrolytic capacitor E2;

[0064] The negative poles of the first electrolytic capacitor E1 and the second electrolytic capacitor E2 are connected to each other and grounded, and the positive poles are connected through the direct current inductor;

[0065] The positive pole of the second electrolytic capacitor E2 is connected to the switching power supply through the voltage output end DC+;

[0066] The switching power supply is a single-ended flyback switching power supply.

[0067] The first connector is a header 9 connector, which includes an L pin, an NN pin, an open-to-position L1 pin, a close-to-position L2 pin, a switch-to-position common end FCOM pin, an open-to-position feedback end FQK pin, a close-to-position feedback end FQG pin, and positive and negative pins of an analog quantity feedback end; the L pin, the open-to-position L1 pin, and the close-to-position L2 pin are connected to a live wire through the same end point, and the NN pin is connected to a zero line.

[0068] Optionally, the functions of the L pin, the NN pin, the open-to-position L1 pin, and the close-to-position L2 pin can be integrated into one pin, which can be called a control end. The functions of the switch-to-position common end FCOM pin, the open-to-position feedback end FQK pin, the close-to-position feedback end FQG pin, and the positive and negative pins of the analog quantity feedback end can also be integrated into one pin, which can be called a feedback end.

[0069] As shown in Figure 3 The single-ended flyback switching power supply provided by the embodiment increases an RC absorption circuit composed of RA3, RA4, RA5, and CA1 in the transformer primary side, which can effectively reduce high-frequency interference signals. Meanwhile, an RC absorption circuit composed of RA12, RA13, and CA4 is added in the transformer secondary side, which further reduces high-frequency interference signals. The primary side and the secondary side are designed to be isolated, and a CA5 capacitor is connected in series between the two "grounds", which can reduce high-frequency interference signals of the secondary power supply and make the power supply ripple cleaner. Finally, through the IC1 optocoupler, closed-loop regulation is realized, so that the power supply voltage is stably output as 24V to provide power supply for the functional circuit in the subsequent stage.

[0070] As shown in Figure 4As shown by the EMC performance test results of the entire power module, the power module has high stability. The blue line is the actual measurement value, and the red line is the corresponding standard value. All actual measurement values are below the standard value, indicating that the test is passed. Similarly, the green line is the actual measurement value, and the light green line is the corresponding standard value. All actual measurement values are below the standard value, indicating that the test is passed.

[0071] As Figure 5 shown, the signal following block provided by the embodiment is an operational amplifier circuit. That is, the output voltage is equal to the input voltage, and the voltage is divided by the variable potentiometer to the positive electrode of the operational amplifier. Due to the characteristics of the operational amplifier input impedance Ri = ∞ and output impedance R0 ≈ 0, the input voltage is equal to the output voltage, the input impedance of the next stage is small, the voltage signal attenuation is small, and the role of isolating the front and rear stages of the circuit is played. The mutual influence between them can be eliminated, making the circuit more stable. Further, an integral circuit composed of R3 and C4 can be added to the output end to eliminate the sudden high pulse signal in the voltage signal.

[0072] PV1, PV2, and PV3 are connected to a 10K potentiometer for opening degree adjustment of the air valve. By adjusting the resistance value of the potentiometer, pin 3 of operational amplifier U1A obtains a varying voltage value UA. According to the circuit principle of U1A operational amplifier, the voltage at pin 1 of U1A is UB = UA.

[0073] As Figure 6 shown, in the differential amplification output block provided by the embodiment, U1B utilizes the differential signal amplification of the operational amplifier to differentially amplify the signal and obtain a varying voltage signal UC at pin 7 of U1B. The value of UC divided by R4 is the base current Ib of the transistor Q1. By utilizing the amplification of the transistor, a constant current source can be obtained, i.e. the current value is Ic = Ib × ɑ, and the values of the zero point potentiometer W2 and the zero point potentiometer W1 can be adjusted to adjust the values of the zero point and the terminal point, respectively, so that the stable output is in the linear interval of 4mA-20mA. Where ɑ is the amplification factor of the transistor.

[0074] As Figure 7As shown, the same-anti-comparison output block provided by the embodiment uses the characteristics of the operational amplifier to make a comparator circuit. Through the value of P1, a voltage value of pin 3 of U2A can be obtained as a threshold voltage of "full off", the voltage value of pin 2 of U2A is compared with the threshold, when the voltage value of pin 2 is less than the value, K1 is a positive level (i.e. 24V), at this time K1 relay is attracted; when the voltage value of pin 2 is greater than the value, K1 is zero level (i.e. 0V), at this time K1 relay is disconnected; and the voltage value of pin 2 of U2A is the current value of the constant current source multiplied by the value of R16. That is, "full off" when the output is 4mA. Through the value of P2, a voltage value of pin 6 of U2B can be obtained as a threshold voltage of "full on", the voltage value of pin 5 of U2B is compared with the threshold, when the voltage value of pin 5 is greater than the value, K2 is a positive level (i.e. 24V), at this time K2 relay is attracted; when the voltage value of pin 5 is less than the value, K2 is zero level (i.e. 0V), at this time K2 relay is disconnected; and the voltage value of pin 5 of U2B is the current value of the constant current source multiplied by the value of R16. That is, "full on" when the output is 20mA current.

[0075] Further, in the embodiment, it can be seen from the PCB wiring that the circuit integration is higher, the wiring is simpler, and the circuit relates to the field of subway mechanical and electrical maintenance, wherein the circuit includes a power supply block, a signal following block, a differential amplification output block, a same-anti-comparison output block and the like electrical structures, adopts an electronic circuit mode to replace a traditional mechanical feedback, does not need complex personnel training, has high installation efficiency, is convenient to maintain, is fast to start and the like. Moreover, since the traditional mechanical feedback has no feedback display, it is difficult to distinguish whether the air valve is adjusted, can only be judged whether the switch is in place by relying on the experience of employees, and safety and accuracy are low during adjustment, the utility model solves the above problems, and makes it fast and easy to adjust and maintain the air valve.

[0076] The specific circuit structure of the air valve analog quantity feedback control circuit provided by the utility model is as follows through the PCB wiring.

[0077] The circuit includes a power supply module, a first connector, a second connector, a signal following block, a differential amplification output block and a same-anti-comparison output block.

[0078] The power supply module includes a rectifier circuit and a switching power supply.

[0079] The first connector includes an L pin, an NN pin, an open-to-place L1 pin, a close-to-place L2 pin, an open-to-place common end FCOM pin, an open-to-place feedback end FQK pin, a close-to-place feedback end FQG pin, and a positive pin and a negative pin of the analog quantity feedback end.

[0080] L pin, open to the L1 pin and close to the L2 pin are connected to the same endpoint of the firewire, the NN pin is connected to the zero line; the open to the L1 pin and the close to the L2 pin are directly connected to the air valve;

[0081] The L pin and the NN pin are connected to the rectifier circuit, and the rectifier circuit is connected to the switching power supply; the switching power supply respectively supplies power to the signal following block, the differential amplification output block and the same-reverse comparison output block;

[0082] The second connector includes a zero line pin, an open valve position pin, a close valve position pin and three control pins connected to the upper computer;

[0083] The zero line pin is connected to the zero line, the open valve position pin is connected to the open to the L1 pin, and the close valve position pin is connected to the close to the L2 pin; the three control pins are respectively connected to the PV1 pin, the PV2 pin and the PV3 pin of the potentiometer on the air valve; the PV1 pin is connected to the output end of the switching power supply through the resistor R24, the PV2 pin is connected to the positive power supply pin of the operational amplifier Y1 in the signal following block through the capacitor L1, and the PV3 pin is grounded through the resistor R17;

[0084] The output end of the signal following block is connected to the negative input pin of the operational amplifier Y2 in the differential amplification output block; the positive input pin of the operational amplifier Y2 is connected to the zero point adjusting potentiometer; one end of the zero point adjusting potentiometer is connected to the output end of the switching power supply through the resistor R6, and the other end is grounded through the resistor R7;

[0085] In the operational amplifier Y2, a capacitor R5 is arranged between the negative input pin and the output pin, the negative input pin is connected to the emitter of the PNP type triode Q1 through the resistor R2, and the output pin is connected to the base of the triode Q1 through the resistor R4;

[0086] In the triode Q1, the emitter is connected to the output end of the switching power supply through the resistor R1 and the terminal adjusting potentiometer in sequence; the collector is connected to the anode of the diode D1 and grounded through the capacitor C7;

[0087] The anode of the diode D1 is connected to the positive pole of the polar capacitor C6, and the cathode is connected to the positive pin of the analog quantity feedback end; the negative pole of the polar capacitor C6 is grounded;

[0088] The negative pin of the analog quantity feedback end is connected to the negative input pin of the same direction operational amplifier Y3 in the same-reverse comparison output block through the resistor R15; the negative input pin of the same direction operational amplifier Y3 is connected to the positive pole of the polar capacitor C9; the negative pole of the polar capacitor C9 is grounded and connected to the negative pin of the analog quantity feedback end through the resistor R16;

[0089] In the same direction operational amplifier Y3, the positive power pin is grounded, the negative power pin is connected to the output terminal of the switching power supply, and a capacitor C8 is arranged between the positive power pin and the negative power pin; the positive input pin is connected to the sliding end of the full-off adjusting potentiometer P1 through a resistor R9, and is sequentially connected to the output terminal of the switching power supply through the resistor R9, a resistor R8 and a resistor R5; a resistor R10 is arranged between the positive input pin and the output pin; the output pin is connected to the base of an NPN type triode Q2 through a resistor R13;

[0090] One end of the full-off adjusting potentiometer P1 is connected to the output terminal of the switching power supply through a resistor R5, and is sequentially grounded through a resistor R8 and a resistor R11; the other end is grounded;

[0091] In the triode Q2, the collector is connected to the cathode of a photoresistor D3 and the anode of a diode D2 through a resistor R12; the emitter is grounded and connected to the base through a resistor R14;

[0092] The anode of the photoresistor D3 and the cathode of the diode D2 are both connected to the output terminal of the switching power supply; the diode D2 is connected in parallel with the first relay; one end of the output loop of the first relay is connected to the switching to position common terminal FCOM pin, and the other end is connected to the switching to position feedback terminal FQG pin;

[0093] The negative input pin of the same direction operational amplifier Y3 is connected to the positive input pin of the reverse direction operational amplifier Y4 in the same-reverse comparison output block through a resistor R22;

[0094] In the reverse direction operational amplifier Y4, the positive input pin is sequentially connected to the output pin through a resistor R18 and a resistor R19, and is sequentially grounded through the resistor R18 and the resistor R19; the negative input pin is connected to the sliding end of a full-on adjusting potentiometer P2; the output pin is connected to the base of an NPN type triode Q3 through a resistor R213;

[0095] One end of the full-on adjusting potentiometer P2 is connected to the output terminal of the switching power supply through a resistor R29, and is connected to the negative input pin of the reverse direction operational amplifier Y4 through a resistor R27; the other end of the full-on adjusting potentiometer P2 is grounded through a resistor R28, and is connected to the negative input pin of the reverse direction operational amplifier Y4 through a resistor R26;

[0096] In the triode Q3, the collector is connected to the cathode of a light emitting diode D5 and the anode of a diode D4 through a resistor R20; the emitter is grounded and connected to the base through a resistor R25;

[0097] The anode of the light emitting diode D5 and the cathode of the diode D4 are both connected to the output terminal of the switching power supply; the diode D4 is connected in parallel with the second relay; one end of the output loop of the second relay is connected to the switching to position common terminal FCOM pin, and the other end is connected to the switching to position feedback terminal FQK pin;

[0098] The output end of the switching power supply is connected to the positive pole of the polarized capacitor C1; the negative pole of the polarized capacitor C1 is grounded; and the voltage stabilizing diode TVS1 is connected in reverse parallel with the polarized capacitor C1.

[0099] The upper computer connected with the second connector is used for sending a control signal, and the potentiometer on the air valve is used for reflecting the current opening and closing state of the air valve.

[0100] In combination with the above embodiments and the drawings, it is easy to see that the air valve analog quantity feedback control circuit directly connects the potentiometer on the air valve through the signal follower, so that the circuit feedback is used to replace the mechanical feedback, thereby reducing the failure rate of the air valve control device and prolonging the effective service life.

[0101] Further, the differential amplification output block and the same-reverse comparison output block are connected through the connector, so that the circuit structure is relatively simple; the DC inductor LX2 is added in the rectifier circuit, which is helpful to reduce the voltage mutation and electromagnetic interference; the two RC absorption circuits added in the single-ended anti-impact switching power supply are both helpful to reduce the high-frequency interference signal, so that the output voltage is more stable; the capacitors are connected in series between the respective ground ends of the primary side and the secondary side, which is helpful to reduce the high-frequency interference signal of the secondary power supply, so that the ripple of the output voltage is more clean.

Claims

1. A damper analog feedback control circuit, characterized by, The signal follower block, the differential amplification output block and the same-reverse comparison output block are connected in sequence. The signal follower block is connected to a potentiometer on the air valve to receive a feedback signal output by the potentiometer; wherein the potentiometer is connected to an upper computer, and the upper computer outputs a control signal to adjust the resistance of the potentiometer; The differential amplification output block is used to convert the current of the output signal of the signal follower into an analog quantity and output the analog quantity; The output end of the same-reverse comparison output block is connected to the air valve to control the opening and closing of the air valve according to the comparison result of the voltage of the analog quantity and a threshold voltage.

2. A wind valve analog feedback control circuit as set forth in claim 1, wherein, The differential amplification output block comprises: In the operational amplifier Y2, the negative input pin is connected to the output end of the signal follower block and connected to the emitter of the PNP type transistor Q1 through the resistor R2; the positive input pin is connected to the zero point potentiometer; one end of the zero point potentiometer is connected to the output end of the switching power supply through the resistor R6, and the other end is grounded through the resistor R7; the output pin is connected to the negative input pin through the capacitor R5, and connected to the base of the transistor Q1 through the resistor R4; In the transistor Q1, the emitter is connected to the power supply in sequence through the resistor R1 and the terminal point potentiometer; the collector is connected to the anode of the diode D1 and grounded through the capacitor C7; The anode of the diode D1 is connected to the positive pole of the polarized capacitor C6, and the cathode is connected to the positive pin of the analog quantity feedback end; the negative pole of the polarized capacitor C6 is grounded.

3. A wind valve analog feedback control circuit as set forth in claim 2, wherein, The same-reverse comparison output block comprises: The negative input pin of the same-direction operational amplifier Y3 is connected to the negative pin of the analog quantity feedback end through the resistor R15, and connected to the positive pole of the polarized capacitor C9; the negative pole of the polarized capacitor C9 is grounded and connected to the negative pin of the analog quantity feedback end through the resistor R16; In the same-direction operational amplifier Y3, the positive power supply pin is grounded, the negative power supply pin is connected to the power supply, and the capacitor C8 is arranged between the positive power supply pin and the negative power supply pin; the positive input pin is connected to the sliding end of the full-off adjusting potentiometer P1 through the resistor R9, and connected to the power supply in sequence through the resistor R9, the resistor R8 and the resistor R5; the resistor R10 is arranged between the positive input pin and the output pin; the output pin is connected to the base of the NPN type transistor Q2 through the resistor R13; One end of the full-off adjusting potentiometer P1 is connected to the power supply through the resistor R5, and grounded in sequence through the resistor R8 and the resistor R11; the other end is grounded; In the transistor Q2, the collector is connected to the cathode of the photoresistor D3 and the anode of the diode D2 through the resistor R12; the emitter is grounded and connected to the base through the resistor R14; The anode of the photoresistor D3 and the cathode of the diode D2 are both connected to the power supply; the diode D2 is connected in parallel with the first relay; one end of the output loop of the first relay is connected to the common end FCOM pin of the switch, and the other end is connected to the feedback end FQG pin of the off-to-position; The negative input pin of the same-direction operational amplifier Y3 is connected to the positive input pin of the reverse-direction operational amplifier Y4 in the same-reverse comparison output block through the resistor R22. In the inverting operational amplifier Y4, the positive input pin is connected to the output pin through the resistor R18 and the resistor R19 in turn, and is grounded through the resistor R18 and the resistor R19 in turn; the negative input pin is connected to the sliding end of the full-on adjusting potentiometer P2; the output pin is connected to the base of the NPN triode Q3 through the resistor R213; One end of the full-on adjusting potentiometer P2 is connected to the power supply through the resistor R29, and is connected to the negative input pin of the inverting operational amplifier Y4 through the resistor R27; the other end of the full-on adjusting potentiometer P2 is grounded through the resistor R28, and is connected to the negative input pin of the inverting operational amplifier Y4 through the resistor R26; In the triode Q3, the collector is connected to the cathode of the light emitting diode D5 and the anode of the diode D4 through the resistor R20; the emitter is grounded, and is connected to the base through the resistor R25; The anode of the light emitting diode D5 and the cathode of the diode D4 are both connected to the power supply; the diode D4 is connected in parallel with the second relay; one end of the output loop of the second relay is connected to the switch-to-position common end FCOM pin, and the other end is connected to the open-to-position feedback end FQK pin; The positive pin and the negative pin of the analog quantity feedback end, the switch-to-position common end FCOM pin, the close-to-position feedback end FQG pin and the open-to-position feedback end FQK pin are all arranged on the connector J2; the connector J2 further comprises the NN pin connected to the zero line, and the L pin, the open-to-position L1 pin and the close-to-position L2 pin connected to the fire line through the same end point.

4. A wind valve analog feedback control circuit as set forth in claim 1, wherein, Further comprising a power module for supplying power to the signal following block, the differential amplification output block and the same-opposite comparison output block.

5. A wind valve analog feedback control circuit as set forth in claim 4, wherein, The power module comprises a rectifier circuit; The rectifier circuit comprises the fuse F1, the voltage-dependent resistor RZ1, the capacitor CX1, the thermistor NTC1, the common-mode inductor LX1, the rectifier bridge DB1, the direct-current inductor LX2, the first electrolytic capacitor E1 and the second electrolytic capacitor E2; The L pin of the first connector is connected to one pin of the input end of the first common-mode inductor LX1 through the fuse F1, and the NN pin is connected to the other pin of the input end of the common-mode inductor LX1 through the thermistor NTC1; One end of the voltage-dependent resistor RZ1 is connected to one pin of the input end of the common-mode inductor LX1, and the other end is connected to the other pin of the input end of the common-mode inductor LX1; The capacitor CX1 is connected in parallel with the thermistor NTC1; The two pins of the output end of the common-mode inductor LX1 are connected to the two pins of the input end of the rectifier bridge DB1 in one-to-one correspondence; One pin of the output end of the rectifier bridge DB1 is connected to the positive pole of the second electrolytic capacitor E2 through the direct-current inductor LX2, and the other pin is connected to the negative pole of the second electrolytic capacitor E2; The negative poles of the first electrolytic capacitor E1 and the second electrolytic capacitor E2 are connected to each other and grounded, and the positive poles are connected through the direct-current inductor; The positive pole of the second electrolytic capacitor E2 is the voltage output end.

6. A wind valve analog feedback control circuit as set forth in claim 4, wherein, The power module comprises a switching power supply; The switching power supply is a single-ended anti-impact switching power supply.

7. A wind valve analog feedback control circuit as set forth in claim 6, wherein, The single-ended anti-impact switching power supply comprises a first RC absorption circuit; The first RC absorption circuit comprises the capacitor CA1 and the resistors RA3, RA4 and RA5, which are connected in parallel with each other; The capacitor CA1 and the resistors RA3, RA4 and RA5 are connected in parallel with each other. One end of the first RC absorption circuit is connected to the output end of the rectifier circuit, the other end is connected to the cathode of diode DA1, and is connected to the same end of the first primary coil of transformer T1 through diode DA1.

8. A wind valve analog feedback control circuit as set forth in claim 6, wherein, The single-ended anti-shock switching power supply comprises a second RC absorption circuit; The second RC absorption circuit is connected in parallel with diode DA4 and comprises capacitor CA4, resistor RA12 and resistor RA13. One end of capacitor CA4 is connected to the same end of the secondary side of transformer T1, and the other end is connected to the cathode of diode DA4 through resistor RA12; resistor RA13 is connected in parallel with resistor RA12.

9. A wind valve analog feedback control circuit as set forth in claim 6, wherein, The single-ended anti-shock switching power supply comprises capacitor CA5; One end of capacitor CA5 is connected to the different end of the second primary coil of transformer T1 and grounded, and the other end is connected to the different end of the secondary side of transformer T1 and grounded.

Images