Electromagnetic lock control circuit

Abstract

The application provides an electromagnetic lock control circuit and relates to the technical field of electromagnetic locks. The circuit comprises a power supply, a switching module, a driving module and a timing charge-discharge module. In the application, when the driving module single-chip microcomputer signal end receives a single-chip microcomputer driving signal, the driving module controls the charging or discharging of the timing charge-discharge module within a preset time, controls the conduction and disconnection of the switching module, and provides a pulse signal within a preset time for the electromagnetic lock. The application can ensure that the electromagnetic lock works under pulse conditions within a certain time, no longer depends on the time requirement of the pulse generated by the single-chip microcomputer, and improves the reliability of the equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic lock, in particular to an electromagnetic lock control circuit. BACKGROUND

[0002] The electromagnetic lock is a principle of generating electricity by using magnetism. When the current passes through the silicon steel sheet, the electromagnetic lock will generate strong suction to tightly attract the adsorption iron plate to achieve the effect of locking the door. At present, the electromagnetic lock is widely used in various application scenarios such as express delivery cabinet, supermarket storage cabinet, electric bicycle battery exchange cabinet, etc. Taking the electric bicycle battery exchange cabinet as an example, due to the convenience and speed of electric bicycle travel, the market has expanded rapidly, and at the same time, the charging safety problem has been a pain point in the industry. Recently, mainstream enterprises have placed equipment outdoors through battery (exchange, rental) cabinet to reduce the risk of charging to personal safety. The battery exchange cabinet is configured with multiple cabins (boxes) to meet the demand of charging multiple batteries at the same time, and the management of charging batteries belongs to a specific person, so an electromagnetic lock must be configured. The working principle of the locking device is that the manual pushing mechanical structure is locked, and the mechanical structure is unlocked by controlling the magnetic field generated by the electromagnet.

[0003] The unlocking power supply requirement of the electromagnetic lock is a pulse within a certain time, such as a pulse within 1s. The general practice of existing products on the market is to use a single-chip microcomputer to generate a 1s pulse, which drives the electromagnetic lock to unlock after passing through a driving circuit. The circuit diagram is shown in Figure 1

[0004] The electromagnetic lock control circuit relies on the stability and reliability of software and single-chip microcomputers. Once a long driving pulse is generated, the electromagnetic lock will be burned out, thereby reducing the reliability of the equipment. SUMMARY

[0005] (I) Technical problems to be solved

[0006] In view of the defects of the prior art, the present application provides an electromagnetic lock control circuit, which solves the technical problem that the existing electromagnetic lock control circuit relies on the stability and reliability of software and single-chip microcomputers, resulting in low reliability of the equipment.

[0007] (II) Technical solutions

[0008] In order to achieve the above purpose, the present application is realized by the following technical solutions:

[0009] The present application provides an electromagnetic lock control circuit, which comprises a power supply, a switch module, a driving module and a timing charge and discharge module, wherein,

[0010] ​The switch module comprises a first connection end, a second connection end and a third connection end, wherein the third connection end is a control end, the first connection end of the switch module is connected with a power supply, and the second connection end of the switch module is connected with a first end of an electromagnetic lock, and a second end of the electromagnetic lock is grounded;

[0011] The timing charge-discharge module comprises a first terminal, a second terminal and a third terminal, wherein the first terminal of the timing charge-discharge module is connected on a common end of the switch module and the power supply, and the second terminal is connected with the control end of the switch module;

[0012] The drive module comprises a single-chip microcomputer signal end, a first end and a second end, wherein the first end of the drive module is connected with the third terminal of the timing charge-discharge module, and the second end is grounded.

[0013] When the single-chip microcomputer signal end of the drive module receives a single-chip microcomputer driving signal, the preset time of the timing charge-discharge module is controlled through the drive module, the switch module is controlled to be turned on or turned off, and a pulse signal within the preset time is provided for the electromagnetic lock.

[0014] Preferably, the timing charge-discharge module comprises a first resistor, a second resistor, an energy storage capacitor and a first diode.

[0015] The first end of the first resistor, the first end of the second resistor and the negative electrode of the first diode are all connected on a common end of the switch module and the power supply; the two ends of the energy storage capacitor are respectively connected with the control end of the switch module and the first end of the drive module; the second end of the first resistor and the positive electrode of the first diode are both connected on a common end of the energy storage capacitor and the switch module; the second end of the second resistor is connected on a common end of the energy storage capacitor and the drive circuit; and the preset time is controlled by the charging time of the energy storage capacitor.

[0016] Preferably, the drive module comprises an NPN-type triode, a first bias resistor and a second bias resistor.

[0017] The first end of the first bias resistor is connected with a pin of the single-chip microcomputer, the second end of the first bias resistor is connected with the base of the NPN-type triode, the first end of the second bias resistor is connected on a common end of the first bias resistor and the NPN-type triode, the second end of the second bias resistor is connected with the emitter of the NPN-type triode, and the two ends are grounded in common; and the collector of the NPN-type triode is connected with the third terminal of the timing charge-discharge module.

[0018] Preferably, the drive module comprises an N-channel field effect transistor, a first bias resistor and a second bias resistor.

[0019] The first end of the first bias resistor is connected to the pin of the single-chip microcomputer, the second end of the first bias resistor is connected to the gate of the N-channel field effect tube, the first end of the second bias resistor is connected to the common end of the first bias resistor and the N-channel field effect tube, the second end of the second bias resistor is connected to the source of the N-channel field effect tube and is grounded in common, and the drain of the N-channel field effect tube is connected to the third terminal of the timing charge-discharge module.

[0020] Preferably, the switch module comprises a P-channel field effect tube, the source of which is connected to the power supply, the drain of which is connected to the first end of the electromagnetic lock, and the gate of which is connected to the second terminal of the timing charge-discharge module.

[0021] Preferably, the circuit further comprises a protection module, the first end of which is grounded, and the second end of which is connected to the common end of the switch module and the electromagnetic lock, wherein the protection module is a one-way conduction circuit from the first end to the second end.

[0022] Preferably, the protection module comprises a freewheeling diode or a voltage stabilizing diode or a transient diode.

[0023] When the protection module uses the voltage stabilizing diode or the transient diode, the voltage stabilizing value of the voltage stabilizing diode or the transient diode is greater than the voltage of the power supply.

[0024] Preferably, the circuit further comprises a fifth resistor, a sixth resistor and an LED in sequence, wherein the two ends of the fifth resistor are connected to the first connection end and the second connection end of the switch module respectively, and the negative electrode of the LED is grounded.

[0025] (Three) beneficial effects

[0026] The present application provides an electromagnetic lock control circuit. Compared with the prior art, the present application has the following beneficial effects:

[0027] In the present application, when the single-chip microcomputer signal end of the driving module receives the single-chip microcomputer driving signal, the driving module controls the charging or discharging of the timing charge-discharge module within a certain time, controls the conduction and disconnection of the switch module, and provides the electromagnetic lock with a pulse signal within a certain time. The present application can ensure that the electromagnetic lock works under pulse conditions within a certain time, and no longer depends on the time requirement of the pulse generated by the single-chip microcomputer, thereby improving the reliability of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0029] Figure 1 Circuit diagram of the control circuit of the existing electromagnetic lock;

[0030] Figure 2 Block diagram of the control circuit of the electromagnetic lock in an embodiment;

[0031] Figure 3 Block diagram of the control circuit of the electromagnetic lock including the protection module in an embodiment;

[0032] Figure 4 Specific circuit diagram of the timing charge-discharge module in an embodiment;

[0033] Figure 5 Circuit diagram of the control circuit of the electromagnetic lock in an embodiment;

[0034] Figure 6 Circuit diagram of the control circuit of the electromagnetic lock including the circuit open, drive indication circuit in an embodiment;

[0035] Figure 7 Schematic diagram of the model and parameter value of each component in an embodiment;

[0036] Figure 8 Circuit diagram of the control circuit of the electromagnetic lock in another embodiment. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0038] The embodiments of the present application provide an electromagnetic lock control circuit, which solves the technical problem that the stability and reliability of the existing electromagnetic lock control circuit depend on software and single-chip microcomputer, resulting in low reliability of the equipment, and ensures that the electromagnetic lock works under the pulse condition within a certain time, thereby improving the reliability of the equipment.

[0039] In order to better understand the above technical solutions, the above technical solutions will be described in detail in combination with the drawings of the specification and specific embodiments.

[0040] The embodiments of the present application provide an electromagnetic lock control circuit, which solves the technical problem that the stability and reliability of the existing electromagnetic lock control circuit depend on software and single-chip microcomputer, resulting in low reliability of the equipment, and ensures that the electromagnetic lock works under the pulse condition within a certain time, thereby improving the reliability of the equipment. Figure 2 The electromagnetic lock control circuit provided by the embodiments of the present application has the advantages that the electromagnetic lock control circuit is stable and reliable, and the reliability of the equipment is improved.

[0041] The switch module comprises a first connection end, a second connection end and a third connection end, wherein the third connection end is a control end, the first connection end of the switch module is connected with a power supply, and the second connection end of the switch module is connected with a first end of an electromagnetic lock, and a second end of the electromagnetic lock is grounded.

[0042] The timing charge-discharge module comprises a first terminal, a second terminal and a third terminal, wherein the first terminal of the timing charge-discharge module is connected on a common terminal of the switch module and the power supply, and the second terminal is connected with the control end of the switch module.

[0043] The drive module comprises a single-chip microcomputer signal end, a first end and a second end, wherein the first end of the drive module is connected with the third terminal of the timing charge-discharge module, and the second end is grounded.

[0044] When the single-chip microcomputer signal end of the drive module receives a single-chip microcomputer driving signal, the preset time of the timing charge-discharge module is controlled through the drive module, the switch module is controlled to be turned on or turned off, and a pulse signal within the preset time is provided for the electromagnetic lock.

[0045] The embodiment of the present application can ensure that the electromagnetic lock works under the pulse condition within the preset time, and no longer depends on the time requirement of the pulse generated by the single-chip microcomputer, thereby improving the reliability of the equipment.

[0046] In an embodiment, since the electromagnetic lock is internally a coil, the current thereof cannot be abruptly changed, and a protection module is arranged to avoid voltage peak, and the structural diagram of the circuit is as shown in Figure 3 In the specific implementation process, a freewheeling diode is generally selected as the protection module.

[0047] Figure 4 A specific circuit diagram of a timing charge-discharge module of an electromagnetic lock control circuit is given, and in the circuit diagram, the timing charge-discharge module comprises a first resistor R1, a second resistor R2, an energy storage capacitor C1 and a first diode D1. Wherein, the first end of the first resistor R1, the first end of the second resistor R2 and the negative electrode of the first diode D1 are all connected on a common terminal of a switch module and a power supply; the two ends of the energy storage capacitor C1 are respectively connected with a control end of the switch module and a first end of a drive module; the second end of the first resistor R1 and the positive electrode of the first diode D1 are both connected on a common terminal of the energy storage capacitor C1 and the switch module; and the second end of the second resistor R2 is connected on a common terminal of the energy storage capacitor C1 and a drive circuit.

[0048] Figure 5 A circuit diagram of an electromagnetic lock control circuit is given, and in the circuit diagram, the circuit of the timing charge-discharge module and Figure 4Consistent, consistent connection. The drive module includes a triode Q1 (the implementation of the NPN type triode), the first bias resistor R3 and the second bias resistor R4. The switch module includes a P-channel field effect transistor Q2. Among them, the first end of the bias resistor R3 is connected to the pin of the single-chip microcomputer, the second end of the bias resistor R3 is connected to the base of the triode Q1, the first end of the bias resistor R4 is connected to the common terminal of the bias resistor R3 and the triode Q1, and the second end of the bias resistor R4 is connected to the emitter of the triode Q1 and is commonly grounded. The collector of the triode Q1 is connected to the gate of the field effect transistor Q2 through the energy storage capacitor C1. The source of the field effect transistor Q2 is connected to the power supply, and the drain of the field effect transistor Q2 is connected to the first end of the electromagnetic lock.

[0049] Figure 5 In the present application, VCC is the power supply for driving the electromagnetic lock, generally 12VDC. JP1 is connected to the terminals of the electromagnetic lock driving coil. The single-chip microcomputer driving signal is an unlock signal generated by the embedded single-chip microcomputer or other master control unit.

[0050] The initial state of the circuit: the single-chip microcomputer driving signal is low or high resistance state, after biasing through resistors R3 and R4, the collector c and the emitter e of Q1 are in the off state. The power supply reaches the two ends of C1 through R1 and R2 respectively, there is no current flow path, i.e. the potential of the two ends of C1 is equal. The source S and the gate G of Q2 are also equipotential, i.e. the source S and the drain D of Q2 are in the off state. The D end of Q2 has no output, and the electromagnetic lock is in the locked state.

[0051] When the driving pulse is high: when the single-chip microcomputer driving pulse output is high, Q1 is driven through R3 current limiting, Q1 C, E is turned on, i.e. C is low, the potential of the two ends of C1 cannot change abruptly (determined by the characteristics of the capacitor), the end connected to R1 of C1 is also low, and the S end of Q2 is the power supply voltage, i.e. a voltage difference is generated between the G and S ends of Q2 to drive the D and S ends to be conductive, and the electromagnetic lock is unlocked. During this period, VCC charges C1 through R1, and the potential of C1 increases, resulting in a decrease in the voltage difference between S and G of Q2, until the voltage difference is higher than the cutoff value (the P-type MOS drive value is negative voltage), and Q2 D, S is cut off. When the single-chip microcomputer driving pulse is continuously high, C1 has completed charging, and the electromagnetic lock driving output has decreased to 0V, at this time the high level has failed, and the electromagnetic lock driving time (i.e. the D, S conduction time of Q2, i.e. the preset time) is controlled by the charging time of C1. The time can be adjusted according to the driving requirements of the electromagnetic lock.

[0052] When the drive pulse is low: the continuous high level has become ineffective. If the microcontroller needs to unlock again at this time (i.e., output a high level), this circuit will not respond because C1 has finished charging. To meet the need for unlocking again, the microcontroller needs to output a low level before the next unlock. When the microcontroller outputs a low level, the collector (C) and emitter (E) of Q1 are cut off, and the discharge path of C1 is D1 and R2. After discharge, the circuit returns to its initial state. The discharge time is controlled by the values ​​of R2 and C1 and can be set as needed.

[0053] To clearly understand the circuit state, such as Figure 6 As shown, Figure 5 The circuit also includes an open-circuit and drive indicator circuit composed of R5, R6, and LED. When the electromagnetic lock is not connected or the electromagnetic lock is internally disconnected (open circuit), the power supply forms a loop through R5, R6, and LED, and the LED emits a weak light, indicating that the electromagnetic lock is not connected or the electromagnetic lock loop is open. When the electromagnetic lock is connected and the electromagnetic lock is not disconnected, the resistance of the electromagnetic lock coil is much smaller than the value of R6. The current through R5 mainly flows through the electromagnetic lock coil, and the voltage drop generated in the R6 and LED branch (equivalent to the two ends of the electromagnetic lock coil) is insufficient to drive the LED to light up. That is, when the electromagnetic lock is properly connected, the LED indicator is off. When properly connected, the drive circuit generates a high level, that is, the drain and source of Q2 are turned on, R5 is short-circuited, and the voltage of R6 and the LED branch is basically the power supply voltage, driving the LED to emit a strong light. At the same time, a protection module freewheeling diode D2 is set to avoid voltage spikes. The group of each component can be set as needed. For example, when using multiple compartments in a battery swapping cabinet for electric bicycles, the values ​​of each component can be set as follows. Figure 7 As shown. Meanwhile, the charging time of C1 was set to be approximately equal to the discharging time, i.e., 0.8s. The capacitance between the gate and source of Q2, and the capacitance between the collector and emitter of Q1, both affect the charging and discharging time of C1. In this example, the value of C1 was adjusted to 4uF based on experimental results.

[0054] It should be noted that the control circuit of this embodiment of the invention may also employ other connection methods or select other components, such as... Figure 8 As shown, D1 and D2 are Zener diodes. D2 can also be a transient diode. When D2 is selected as a Zener diode or a transient diode, its Zener voltage is greater than the power supply voltage. Q1 is an N-channel MOSFET.

[0055] In summary, compared with existing technologies, it has the following beneficial effects:

[0056] 1. In this embodiment of the invention, when the microcontroller signal terminal of the drive module receives a microcontroller drive signal, the drive module controls the charging or discharging of the timed charging and discharging module within a certain period of time, controlling the on and off of the switch module, thus providing a pulse signal for the electromagnetic lock within a certain period of time. This embodiment of the invention can ensure that the electromagnetic lock operates under pulse conditions within a certain period of time, no longer relying on the timing requirements of the pulses generated by the microcontroller, thereby improving the reliability of the equipment.

[0057] 2. When the microcontroller drive pulse in this embodiment of the invention is continuously high, C1 has completed charging, and the electromagnetic lock drive output has dropped to 0V. At this time, the high level is invalid. The electromagnetic lock drive time (i.e., the D and S conduction time of Q2) is controlled by the charging time of C1. The time can be adjusted according to the drive requirements of the electromagnetic lock by adjusting the values ​​of R1 and C1. This avoids the situation where the microcontroller program gets stuck in an infinite loop, causing the electromagnetic lock drive signal to continuously output a high level.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electromagnetic lock control circuit, characterized in that, It includes a power supply, a switching module, a drive module, and a timed charge / discharge module, among which, The switch module includes a first connection terminal, a second connection terminal, and a third connection terminal, wherein the third connection terminal is a control terminal, the first connection terminal of the switch module is connected to the power supply, the second connection terminal of the switch module is connected to the first terminal of the electromagnetic lock, and the second terminal of the electromagnetic lock is grounded. The timed charge / discharge module includes a first terminal, a second terminal, and a third terminal. The first terminal of the timed charge / discharge module is connected to the common terminal of the switch module and the power supply, and the second terminal is connected to the control terminal of the switch module. The driving module includes a microcontroller signal terminal, a first terminal, and a second terminal. The first terminal of the driving module is connected to the third terminal of the timing charge and discharge module, and the second terminal is grounded. When the microcontroller signal terminal of the drive module receives the microcontroller drive signal, the drive module controls the charging or discharging of the timed charging and discharging module within a preset time, controls the conduction and disconnection of the switch module, and provides the electromagnetic lock with a pulse signal within a preset time. The timing charge / discharge module includes: a first resistor, a second resistor, an energy storage capacitor, and a first diode; The first end of the first resistor, the first end of the second resistor, and the negative terminal of the first diode are all connected to the common terminal of the switching module and the power supply; the two ends of the energy storage capacitor are respectively connected to the control terminal of the switching module and the first end of the drive module; the second end of the first resistor and the positive terminal of the first diode are both connected to the common terminal of the energy storage capacitor and the switching module; the second end of the second resistor is connected to the common terminal of the energy storage capacitor and the drive circuit. The preset time is controlled by the charging time of the energy storage capacitor; the values ​​of the first resistor and the energy storage capacitor are adjusted according to the driving requirements of the electromagnetic lock, thereby adjusting the preset time. The driving module includes an NPN transistor, a first bias resistor, and a second bias resistor. The first end of the first bias resistor is connected to the pin of the microcontroller, the second end of the first bias resistor is connected to the base of the NPN transistor, the first end of the second bias resistor is connected to the common terminal of the first bias resistor and the NPN transistor, the second end of the second bias resistor is connected to the emitter of the NPN transistor and is grounded together; the collector of the NPN transistor is connected to the third terminal of the timing charge and discharge module. Alternatively, the driving module includes an N-channel field-effect transistor, a first bias resistor, and a second bias resistor; The first end of the first bias resistor is connected to the pin of the microcontroller, the second end of the first bias resistor is connected to the gate of the N-channel field-effect transistor, the first end of the second bias resistor is connected to the common terminal of the first bias resistor and the N-channel field-effect transistor, the second end of the second bias resistor is connected to the source of the N-channel field-effect transistor and is grounded together; the drain of the N-channel field-effect transistor is connected to the third terminal of the timing charge-discharge module.

2. The electromagnetic lock control circuit as described in claim 1, characterized in that, The switching module includes a P-channel field-effect transistor, whose source is connected to the power supply, whose drain is connected to the first terminal of the electromagnetic lock, and whose gate is connected to the second terminal of the timed charge-discharge module.

3. The electromagnetic lock control circuit as described in claim 1, characterized in that, The circuit further includes: a fifth resistor, a sixth resistor, and an LED in sequence, wherein the two ends of the fifth resistor are connected to the first connection terminal and the second connection terminal of the switch module, respectively, and the negative terminal of the LED is grounded.

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