Access control switch control circuit and access control device

Abstract

The utility model provides an entrance guard switch control circuit and an entrance guard device, relates to the entrance guard technical field, said circuit includes: isolation device, switch circuit, first power supply, door lock power supply and motor, wherein: isolation device connects entrance guard, ground terminal and switch circuit, switch circuit connects first power supply, door lock power supply and motor, door lock power supply also connects motor, and the motor is connected with the motor. The motor is also connected with the entrance guard; the entrance guard is used for generating an entrance guard control signal; the isolation device is used for generating a switch control signal based on the access control signal; the switch control signal is used for controlling the on-off state of the switch circuit; the on-off state of the switch circuit is used for controlling whether the door lock power supply supplies power to the motor or not; the power supply state of the motor is used for controlling the locking state of the access control. According to the utility model, mistaken touch of the relay caused by external force vibration can be avoided, the problem of abnormal door opening caused by external force vibration is solved, and the safety risk in the door opening and closing process of the entrance guard is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to access control technical field especially, relate to an access control switch control circuit and access control device. BACKGROUND

[0002] In the linkage scene of access control and intelligent lock, the access control will be the front recognition device of face authority, and after obtaining the face authority, the door opening signal is transmitted to the relay, the power element power supply module of intelligent lock is turned on through the closure of relay, and the door is opened by the power element. However, when the vibration of access control is large in the opening and closing process, the relay will be mis-triggered and automatically open the door without obtaining the face authority, which has great safety hazards.

[0003] In the prior art, the relay with better anti-vibration characteristics is used to alleviate the abnormal door opening problem caused by external vibration to a certain extent, but when the external vibration is large, the abnormal door opening problem cannot be solved. INVENTION CONTENTS

[0004] The utility model provides a kind of access control switch control circuit and access control device to solve the defect of abnormal door opening caused by relay by external vibration in prior art.

[0005] The utility model provides an access control switch control circuit, comprising: isolating device, switching circuit, first power supply, door lock power supply and motor, wherein:

[0006] The isolating device is connected with access control, ground terminal and the switching circuit, the switching circuit is connected with the first power supply, the door lock power supply and the motor, the door lock power supply is also connected with the motor, and the motor is also connected with the access control;

[0007] The access control is used to generate access control signal;The isolating device is used to generate switching control signal based on the access control signal;The switching control signal is used to control the on-off state of the switching circuit;The on-off state of the switching circuit is used to control whether the door lock power supply supplies the power supply state of the motor;The power supply state of the motor is used to control the locking state of the access control.

[0008] According to the access control switch control circuit provided by the utility model, the isolating device includes photoelectric coupler or transformer coil, wherein:

[0009] The first end of the photoelectric coupler or the transformer coil is connected with the access control, the second end of the photoelectric coupler or the transformer coil is connected with reference ground in the ground terminal, the third end of the photoelectric coupler or the transformer coil is connected with the first end of the switching circuit, and the fourth end of the photoelectric coupler or the transformer coil is connected with signal ground in the ground terminal.

[0010] According to the access control switch control circuit, the photoelectric coupler comprises a light-emitting diode and a photoelectric triode, wherein:

[0011] The anode of the light-emitting diode is used as the first end of the photoelectric coupler, and the cathode of the light-emitting diode is used as the second end of the photoelectric coupler.

[0012] The collector of the photoelectric triode is used as the third end of the photoelectric coupler, and the emitter of the photoelectric triode is used as the fourth end of the photoelectric coupler.

[0013] The access control signal is used for controlling the light-emitting state of the light-emitting diode, and the photoelectric triode is used for generating a switch control signal based on the light-emitting state of the light-emitting diode.

[0014] According to the access control switch control circuit, the transformer coil comprises a primary coil and a secondary coil, wherein:

[0015] The first end of the primary coil is used as the first end of the transformer coil, the second end of the primary coil is used as the second end of the transformer coil, the first end of the secondary coil is used as the third end of the transformer coil, and the second end of the secondary coil is used as the fourth end of the transformer coil.

[0016] According to the access control switch control circuit, the switch circuit comprises a current-limiting resistor and a switch sub-circuit, wherein:

[0017] The first end of the current-limiting resistor is connected to the first end of the switch sub-circuit and is used as the first end of the switch circuit, and the second end of the current-limiting resistor is connected to the first power supply.

[0018] The second end of the switch sub-circuit is connected to the door lock power supply, and the third end of the switch sub-circuit is connected to the motor.

[0019] According to the access control switch control circuit, the switch sub-circuit comprises a MOS tube Q1 and a MOS tube Q2, wherein:

[0020] The gate of the MOS tube Q1 is connected to the gate of the MOS tube Q2 and is used as the first end of the switch sub-circuit, the drain of the MOS tube Q1 is used as the second end of the switch sub-circuit, the source of the MOS tube Q1 is connected to the source of the MOS tube Q2, the drain of the MOS tube Q2 is used as the third end of the switch sub-circuit, and the type of the MOS tube Q1 is the same as that of the MOS tube.

[0021] According to the access control switch control circuit, the first parasitic diode is opposite to the second parasitic diode in the conduction direction.

[0022] According to the access control switch control circuit, the first parasitic diode is opposite to the second parasitic diode in the conduction direction.

[0023] According to the access control switch control circuit, the first parasitic diode is opposite to the second parasitic diode in the conduction direction.

[0024] The utility model also provides a kind of access control device, including access control and the access control switch control circuit as described in any of the above.

[0025] The access control switch control circuit and the access control device provided by the utility model, after access control generates access control signal, isolating device generates switch control signal according to access control signal, and the on-off state of switch circuit is controlled by switch control signal, and then whether the power supply state of motor is powered by door lock power supply is controlled, to control the action of motor, to control the locking state of access control.In the utility model, isolating device and switch circuit are used to replace relay, and the mechanical attraction action in relay is replaced by the electric signal between isolating device and switch circuit to control access control switch, and access control switch process is only controlled by electric signal, and electric signal is not influenced by external vibration to change, avoid the error touch of relay due to external vibration, solve the problem of abnormal door opening due to external vibration, greatly reduce the security risk of access control switch door process. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the utility model or prior art, the following will be a simple introduction to the drawings needed to be used in embodiment or prior art description, obviously, the following description of drawings is some embodiments of the utility model, for those skilled in the art, without creative labor, other drawings can also be obtained according to these drawings.

[0027] Figure 1 It is the connection schematic diagram of access control switch control circuit provided by the utility model embodiment.

[0028] Figure 2 It is the structure schematic diagram of photoelectric coupler provided by the utility model embodiment.

[0029] Figure 3 It is the structure schematic diagram of transformer coil provided by the utility model embodiment.

[0030] Figure 4It is the structural schematic view of the access control switch control circuit provided by the embodiment of the utility model.

[0031] Reference signs:

[0032] 100: access control switch control circuit; 110: isolation device; 111: photoelectric coupler; 112: transformer coil; 120: switch circuit; 121: switch sub-circuit; 130: door lock power supply; 200: ground terminal; 300: access control. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantage of the utility model more clear, the technical scheme in the utility model will be described clearly and completely below in combination with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0034] In view of the problem that the relay is abnormally opened due to external force vibration in the prior art, the embodiment of the utility model provides an access control switch control circuit, Figure 1 It is the connection schematic view of the access control switch control circuit provided by the embodiment of the utility model, as Figure 1 Indicated, the access control switch control circuit 100 includes: isolation device 110, switch circuit 120, first power supply VCC, door lock power supply 130 and motor M.

[0035] The isolation device 110 is connected with the access control 300, the ground terminal 200 and the switch circuit 120, the switch circuit 120 is connected with the first power supply VCC, the door lock power supply 130 and the motor M, the door lock power supply 130 is also connected with the motor M, and the motor M is also connected with the access control 300.

[0036] The access control 300 is used to generate an access control signal IN; the isolation device 110 is used to generate a switch control signal based on the access control signal IN; the switch control signal is used to control the on-off state of the switch circuit 120; the on-off state of the switch circuit 120 is used to control whether the door lock power supply 130 supplies the power supply state of the motor M; and the power supply state of the motor M is used to control the locking state of the access control 300.

[0037] Specifically, the access control 300 generates an access control signal IN after obtaining the face permission, and sends the access control signal IN to the isolation device 110. After receiving the access control signal IN, the isolation device 110 generates a switch control signal according to the access control signal IN, and isolates the access control signal IN from the switch control signal, that is, realizes the isolation between the main control circuit where the access control signal IN is located and the power load circuit where the motor M is located, to ensure the safety of the main control circuit. The switch control signal can be understood as the opening voltage of the switch circuit 120. By controlling whether the opening voltage of the switch circuit 120 is provided by the first power supply VCC or the ground end 200, the on-off state of the switch circuit 120 is controlled. In the power load circuit including the switch circuit 120, the motor M and the door lock power supply 130, the switch circuit 120 serves as a switch of the power load circuit, and the on-off state of the switch circuit 120 directly affects the power supply state of the motor M, that is, if the switch circuit 120 is in the on state, the door lock power supply 130 can supply power to the motor M, and if the switch circuit 120 is in the off state, the door lock power supply 130 cannot supply power to the motor M. The power supply state of the motor M directly affects the locking state of the access control 300, that is, whether the motor M can drive the access control 300 to switch the lock.

[0038] In the embodiment of the utility model, the isolation device 110 and the switch circuit 120 replace the mechanical relay in the traditional access control, and the access switch is controlled by the electric signal not affected by external vibration, to avoid the problem of abnormal door opening caused by the sudden change of internal contact connection state due to the mis-touch of the relay after the relay is vibrated by external force, thereby improving the safety during the process of opening and closing the access switch. In addition, the mechanical relay has an upper limit for the number of switching times, and the mis-touch of the relay during the vibration process will inevitably affect the service life of the relay. After the electric signal is used to control the access switch, the service life problem of the relay can be fundamentally solved.

[0039] Further, the isolation device 110 includes a photoelectric coupler 111 or a transformer coil 112, wherein:

[0040] The first end of the photoelectric coupler 111 or the transformer coil 112 is connected to the access control 300, the second end of the photoelectric coupler 111 or the transformer coil 112 is connected to the reference ground GND in the ground end 200, the third end of the photoelectric coupler 111 or the transformer coil 112 is connected to the first end of the switch circuit 120, and the fourth end of the photoelectric coupler 111 or the transformer coil 112 is connected to the signal ground BGND in the ground end 200.

[0041] Specifically, in the isolation device 110, the optoelectronic coupler 111 is a kind of semiconductor device for realizing the isolation of access control signal IN and switch control signal using photoelectric effect, the optoelectronic coupler 111 generates switch control signal based on the converted electrical signal after converting access control signal IN into optical signal and then converting optical signal into electrical signal, since optical signal is unidirectional transmission, it can block the electrical contact between converted electrical signal and input access control signal IN, but does not cut off the signal transmission between the two signals, thereby realizing the purpose of isolating access control signal IN and switch control signal.

[0042] Further, Figure 2 It is the structure diagram of the optoelectronic coupler 111 provided by the embodiment of the utility model, as Figure 2 Indicated, the optoelectronic coupler 111 includes light-emitting diode D1 and photoelectric triode SW1, wherein:

[0043] The anode of the light-emitting diode D1 is used as the first end of the optoelectronic coupler 111, and the cathode of the light-emitting diode D1 is used as the second end of the optoelectronic coupler 111;

[0044] The collector of the photoelectric triode SW1 is used as the third end of the optoelectronic coupler 111, and the emitter of the photoelectric triode SW1 is used as the fourth end of the optoelectronic coupler 111;

[0045] The access control signal IN is used to control the light-emitting state of the light-emitting diode D1, and the photoelectric triode SW1 is used to generate switch control signal based on the light-emitting state of the light-emitting diode D1.

[0046] Specifically, in Figure 2The photoelectric coupler 111 is shown, after the face recognition obtains the access permission, that is, when the door needs to be opened, the access control signal IN input to the anode of the light emitting diode D1 of the access control 300 is a low level signal, at this time, the cathode of the light emitting diode D1 is connected to the reference ground GND in the ground end 200, that is, the voltage difference between the two ends of the light emitting diode D1 is small, so that the light emitting diode D1 is in an off state, that is, the light emitting diode D1 does not emit light. The phototriode SW1 in the photoelectric coupler 111 is a photosensitive device, and the on-off state of the phototriode SW1 depends on whether the light signal is received. The phototriode SW1 is in an off state when no light signal of the light emitting diode D1 is received. Since the switch circuit 120 is connected to the first power supply VCC, the opening voltage of the switch circuit 120 is high by default. At this time, the emitter of the phototriode SW1 is connected to the signal ground BGND in the ground end 200, which cannot pull down the opening voltage of the switch circuit 120, so that the switch control signal input to the switch circuit 120 is a high level signal, that is, the opening voltage of the switch circuit 120 still remains high. At this time, the opening voltage depends on the output voltage of the first power supply VCC.

[0047] When the access permission is not obtained in the face recognition, that is, when the door needs to be closed, the access control signal IN input to the anode of the light emitting diode D1 of the access control 300 is a high level signal, at this time, the voltage difference between the two ends of the light emitting diode D1 is large, the light emitting diode D1 is turned on and starts to emit light, that is, the light emitting diode D1 converts the access control signal IN into a light signal. After the light emitting diode D1 emits light, the light signal is transmitted to the phototriode SW1, and the phototriode SW1 is in a conductive state. At this time, the signal ground BGND connected to the emitter of the phototriode SW1 pulls down the opening voltage of the switch circuit 120, that is, so that the switch control signal input to the switch circuit 120 is a low level signal.

[0048] Further, Figure 3 It is a structure diagram of the transformer coil 112 provided by the embodiment of the utility model, as shown in Figure 3 The transformer coil 112 includes a primary coil and a secondary coil, wherein:

[0049] The first end of the primary coil is the first end of the transformer coil 112, the second end of the primary coil is the second end of the transformer coil 112, the first end of the secondary coil is the third end of the transformer coil 112, and the second end of the secondary coil is the fourth end of the transformer coil 112.

[0050] Specifically, the transformer coil 112 works based on electromagnetic induction phenomenon, in the transformer coil 112, the primary coil and the secondary coil are wound on the same core, when alternating current passes through the primary coil, a changing magnetic field is generated in the core, and the changing magnetic field induces an electromotive force in the secondary coil, thereby generating a current on the secondary coil side, since there is a magnetic coupling between the primary coil and the secondary coil without direct electrical connection, therefore, the transformer coil 112 can realize the isolation between the access control signal IN and the switch control signal.

[0051] Further, the switch circuit 120 comprises a current-limiting resistor R and a switch sub-circuit 121, wherein:

[0052] The first end of the current-limiting resistor R is connected to the first end of the switch sub-circuit 121, and the current-limiting resistor R is connected to the first power supply VCC as the first end of the switch circuit 120;

[0053] The second end of the switch sub-circuit 121 is connected to the door lock power supply 130, and the third end of the switch sub-circuit 121 is connected to the motor M.

[0054] Further, the switch sub-circuit 121 comprises a MOS tube Q1 and a MOS tube Q2, wherein:

[0055] The gate of the MOS tube Q1 is connected to the gate of the MOS tube Q2, and the drain of the MOS tube Q1 is connected to the source of the MOS tube Q2 as the second end of the switch sub-circuit 121, and the source of the MOS tube Q1 is connected to the source of the MOS tube Q2 as the third end of the switch sub-circuit 121; the type of the MOS tube Q1 is the same as that of the MOS tube.

[0056] The MOS tube Q1 and the MOS tube Q2 in the switch sub-circuit 121 can be N-type MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-oxide semiconductor field effect transistor). The switch control signal generated by the isolating device 110 acts on the gates of the MOS tube Q1 and the MOS tube Q2.

[0057] For example, Figure 4 is a structural diagram of the access switch control circuit provided by the embodiment of the utility model, as Figure 4 As shown in the drawing, taking the isolating device 110 as the photoelectric coupler 111 as an example, when the door needs to be opened, the switch control signal generated by the photoelectric triode SW1 is a high-level signal, that is, the gates of the MOS tube Q1 and the MOS tube Q2 are all high-level signals, so that the gate-source voltage Vgs1 of the MOS tube Q1 is greater than the gate-source threshold voltage Vgs1th , and the gate-source voltage Vgs2 of the MOS tube Q2 is also greater than the gate-source threshold voltage Vgs2 th , and the gate-source voltage Vgs2 of the MOS tube Q2 is also greater than the gate-source threshold voltage Vgs2

[0058] When the door needs to be closed, the switch control signal generated by the phototriode SW1 is a low-level signal, that is, the gate of the MOS tube Q1 and the gate of the MOS tube Q2 are both low-level signals, so that the gate-source voltage Vgs1 of the MOS tube Q1 is less than the gate-source threshold voltage Vgs1 th , and the gate-source voltage Vgs2 of the MOS tube Q2 is also less than the gate-source threshold voltage Vgs2 th , and the gate-source voltage Vgs2 of the MOS tube Q2 is also less than the gate-source threshold voltage Vgs2

[0059] Further, the door lock power supply 130 comprises a direct current source or an alternating current source.

[0060] It should be noted that the supply voltage of the door lock power supply 130 is lower than the output voltage of the first power supply VCC, and the voltage difference between the output voltage of the first power supply VCC and the supply voltage of the door lock power supply 130 is greater than the gate-source threshold voltage of the MOS tube Q1 and the MOS tube Q2 in the switch sub-circuit 121.

[0061] The access control switch control circuit provided by the embodiment of the utility model can be applied to direct current application scenarios and alternating current application scenarios, and has a wide application range.

[0062] Further, as shown in Figure 4 , the source and the drain of the MOS tube Q1 are connected in parallel with a first parasitic diode, the source and the drain of the MOS tube Q2 are connected in parallel with a second parasitic diode, and the conduction direction of the first parasitic diode is opposite to the conduction direction of the second parasitic diode.

[0063] Specifically, when the door lock power supply 130 is an alternating current source, the door lock power supply 130 outputs a bidirectional current, which results in that half of the period cannot completely close the door. Taking the door lock power supply 130 outputting a forward current as an example, that is, the door lock power supply 130 outputs a counterclockwise current, if the conduction direction of the first parasitic diode of the MOS tube Q1 is the same as the conduction direction of the second parasitic diode of the MOS tube Q2, and both are the direction from the MOS tube Q1 to the MOS tube Q2, when the door needs to be closed, even if the MOS tube Q1 and the MOS tube Q2 are both in the off state, the forward current output by the door lock power supply 130 still supplies power to the motor M through the first parasitic diode and the second parasitic diode, and the MOS tube Q1 and the MOS tube Q2 cannot realize the closing of the door. Therefore, the MOS tube Q1 and the MOS tube Q2 are designed in a back-to-back manner, that is, the conduction direction of the first parasitic diode of the MOS tube Q1 is different from the conduction direction of the second parasitic diode of the MOS tube Q2, when the door needs to be closed, after the MOS tube Q1 and the MOS tube Q2 are both controlled to be in the off state, the first parasitic diode or the second parasitic diode with the conduction direction different from the direction of the forward current output by the door lock power supply 130 blocks the forward current flowing to the motor M, so that the motor M is powered off. The working principle when the door lock power supply 130 outputs a reverse current is similar to the above, which will not be described herein again.

[0064] In the embodiment of the utility model, through the design of the back-to-back double MOS tubes, the problem that a single MOS tube cannot support an alternating current application scenario can be solved.

[0065] Further, the access control switch control circuit further includes a TVS (Transient Voltage Suppressor, transient voltage suppression diode) D2, which is connected in parallel across the motor M.

[0066] Specifically, in the embodiment of the utility model, since the motor M is an inductive load, transient peak energy is generated during switching. The TVS D2 is an overvoltage protection device with bidirectional voltage stabilization and bidirectional negative resistance characteristics. After the motor M generates transient peak energy, the TVS D2 connected in parallel across the motor M can quickly break down the Zener, change from a high resistance state to a low resistance state, shunt and embed the transient peak energy, suppress the transient peak energy, protect the front-end circuit from the impact of the transient peak energy, and ensure the reliability of the front-end circuit.

[0067] The gate control switch control circuit provided by the utility model, after the gate control 300 generates the gate control signal IN, the isolation device 110 generates the switch control signal according to the gate control signal IN, the on-off state of the switch circuit 120 is controlled through the switch control signal, and then whether the motor M is powered by the power supply state of the door lock power supply 130 is controlled, the action of the motor M is controlled, and the locking state of the gate control 300 is controlled. In the utility model, the relay is replaced by the isolation device 110 and the switch circuit 120 and other electronic components, the mechanical attraction action in the relay is replaced by the electric signal between the isolation device and the switch circuit 120 to control the gate control 300 switch, the gate control 300 switch process is only controlled by the electric signal, and the electric signal is not influenced by the external force vibration and is changed, the relay is avoided from being touched by mistake due to the external force vibration, the problem that the door is abnormally opened due to the external force vibration is solved, and the safety risk of the gate control door opening process is greatly reduced.

[0068] The utility model embodiment further provides a kind of gate control device, including gate control and the gate control switch control circuit as described in any of the above.

[0069] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. An access switch control circuit, characterized in that: include: An isolation device, a switch circuit, a first power supply, a door lock power supply, and a motor, wherein: The isolation device is connected to the access control, the ground terminal and the switch circuit, the switch circuit is connected to the first power supply, the door lock power supply and the motor, the door lock power supply is also connected to the motor, and the motor is also connected to the access control; The access control is used to generate an access control signal; the isolation device is used to generate a switch control signal based on the access control signal; the switch control signal is used to control the on-off state of the switch circuit; the on-off state of the switch circuit is used to control the power supply state of the door lock power supply to power the motor; the power supply state of the motor is used to control the locking state of the access control.

2. The access switch control circuit according to claim 1, characterized in that: The isolation device includes a photocoupler or a transformer coil, wherein: The first end of the photoelectric coupler or the transformer coil is connected to the access control, the second end of the photoelectric coupler or the transformer coil is connected to the reference ground in the ground end, the third end of the photoelectric coupler or the transformer coil is connected to the first end of the switching circuit, and the fourth end of the photoelectric coupler or the transformer coil is connected to the signal ground in the ground end.

3. The access switch control circuit according to claim 2, characterized in that: The photoelectric coupler includes a light emitting diode and a phototransistor, wherein: The anode of the light emitting diode serves as the first end of the photoelectric coupler, and the cathode of the light emitting diode serves as the second end of the photoelectric coupler; The collector of the phototransistor serves as the third terminal of the photoelectric coupler, and the emitter of the phototransistor serves as the fourth terminal of the photoelectric coupler; The access control signal is used to control the light emitting state of the light emitting diode, and the phototransistor is used to generate a switch control signal based on the light emitting state of the light emitting diode.

4. The access switch control circuit according to claim 2, characterized in that: The transformer coil includes a primary coil and a secondary coil, wherein: The first end of the primary coil serves as the first end of the transformer coil, the second end of the primary coil serves as the second end of the transformer coil, the first end of the secondary coil serves as the third end of the transformer coil, and the second end of the secondary coil serves as the fourth end of the transformer coil.

5. The access switch control circuit according to any one of claims 1 to 4, characterized in that: The switch circuit includes a current limiting resistor and a switch subcircuit, wherein: The first end of the current-limiting resistor is connected to the first end of the switch sub-circuit and serves as the first end of the switch circuit, and the second end of the current-limiting resistor is connected to the first power supply; The second end of the switch subcircuit is connected to the door lock power supply, and the third end of the switch subcircuit is connected to the motor.

6. The access switch control circuit according to claim 5, characterized in that: The switch sub-circuit includes a MOS transistor Q1 and a MOS transistor Q2, wherein: The gate of the MOS transistor Q1 is connected to the gate of the MOS transistor Q2 and serves as the first end of the switch sub-circuit. The drain of the MOS transistor Q1 serves as the second end of the switch sub-circuit. The source of the MOS transistor Q1 is connected to the source of the MOS transistor Q2, and the drain of the MOS transistor Q2 serves as the third end of the switch sub-circuit. The type of the MOS transistor Q1 is the same as that of the MOS transistor.

7. The access switch control circuit according to claim 6, characterized in that: A first parasitic diode is connected in parallel between the source and drain of the MOS transistor Q1 , and a second parasitic diode is connected in parallel between the source and drain of the MOS transistor Q2 . The conduction direction of the first parasitic diode is opposite to that of the second parasitic diode.

8. The access switch control circuit according to any one of claims 1 to 4, characterized in that: A TVS is also included, and the TVS is connected in parallel to both ends of the motor.

9. The access switch control circuit according to any one of claims 1 to 4, characterized in that: The door lock power supply includes a DC source or an AC source.

10. An access control device, characterized in that: The invention comprises an access control system and an access switch control circuit as claimed in any one of claims 1 to 9.

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