Small current driving system based on relay control and lifting device

Abstract

The application relates to the field of electronic technology, in particular to a small-current driving system based on relay control and a lifting device, which comprises a first control switch for controlling motor reverse rotation, a first control circuit for controlling the conduction of a loop where the first control switch is located, a second control circuit for controlling the conduction of a loop where a motor is located, a second control switch for controlling motor forward rotation, a third control circuit for controlling the conduction of a loop where the second control switch is located, and a fourth control circuit for controlling the conduction of a loop where the motor is located; the first control circuit is connected with a third control switch for controlling the conduction of the first control circuit; when the motor reverse rotation drives the push rod to move and triggers the third control switch, the motor stops rotating; the third control circuit is connected with a fourth control switch for controlling the conduction of the third control circuit; when the motor forward rotation drives the push rod to move and triggers the fourth control switch, the motor stops rotating. The application realizes the control of motor operation through a small-current control signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronics, and in particular to a small-current driving system based on relay control and a lifting device. BACKGROUND

[0002] Generally, a push rod has a certain stroke distance, in order to stop the push rod when it reaches the limit position, facilitate stable control of the push rod stroke distance, and prevent the push rod from being damaged due to exceeding the stroke distance. In the prior art, the push rod is directly controlled, and a travel switch is used to turn on and off the motor line to realize push rod stroke control. However, because the motor normally operates with a large current of several amperes, directly turning on and off the motor line will greatly affect the service life of the travel switch and reduce the service life of the travel switch. SUMMARY

[0003] To solve the above problems, the present application provides a small-current driving system based on relay control and a lifting device.

[0004] The small-current driving system based on relay control comprises a first control switch for controlling the reverse rotation of a motor, a first control circuit connected with the first control switch and used for controlling the conduction of a loop in which the first control switch is located, a second control circuit connected with the first control circuit and used for controlling the conduction of a loop in which the motor is located, a second control switch for controlling the forward rotation of the motor, a third control circuit connected with the second control switch and used for controlling the conduction of a loop in which the second control switch is located, and a fourth control circuit connected with the third control circuit and used for controlling the conduction of a loop in which the motor is located. The first control circuit is connected with a third control switch used for controlling the conduction of the first control circuit through a small-current signal. When the motor reversely rotates to drive the push rod to trigger the third control switch, the motor stops rotating. The third control circuit is connected with a fourth control switch used for controlling the conduction of the third control circuit through a small-current signal. When the motor forwardly rotates to drive the push rod to trigger the fourth control switch, the motor stops rotating.

[0005] Preferably, the first control circuit comprises a transistor Q1, a diode D3, and a resistor R1. The base of the transistor Q1 is connected with one end of the resistor R1, the collector of the transistor Q1 is connected with the second control circuit, the emitter of the transistor Q1 is connected with the positive electrode of the diode D3, the other end of the resistor R1 is connected with a common ground GND, and the negative electrode of the diode D3 is connected with the first control switch.

[0006] Preferably, the second control circuit includes a relay KA1 and a diode D1, one end of the winding of the relay KA1 is connected to the first power supply terminal VCC, and the other end is connected to the first control circuit, the common contact of the relay KA1 is connected to the negative pole of the motor, the normally closed contact of the relay KA1 is connected to the common ground GND and the fourth control circuit, the normally open contact of the relay KA1 is connected to the first power supply terminal VCC and the fourth control circuit, the positive pole of the diode D1 is connected to the first control circuit, and the negative pole of the diode D1 is connected to the first power supply terminal VCC.

[0007] Preferably, the third control circuit includes a transistor Q2, a diode D4, and resistors R2 and R3. The base of the transistor Q2 is connected to one end of the resistors R2 and R3, the collector of the transistor Q2 is connected to the fourth control circuit, the emitter of the transistor Q2 is connected to the positive electrode of the diode D4, the other end of the resistor R2 is connected to the common ground GND, the other end of the resistor R3 is connected to the second power supply terminal IDET1, and the cathode of the diode D4 is connected to the second control switch.

[0008] Preferably, the fourth control circuit includes a relay KA2 and a diode D2, one end of the winding of the relay KA2 is connected to the first power supply terminal VCC, and the other end is connected to the third control circuit, the common contact of the relay KA2 is connected to the positive pole of the motor, the normally closed contact of the relay KA2 is connected to the common ground GND, the normally open contact of the relay KA1 is connected to the first power supply terminal VCC, the positive pole of the diode D2 is connected to the third control circuit, and the negative pole of the diode D2 is connected to the first power supply terminal VCC.

[0009] Preferably, the third control switch is a normally closed control switch K3, and the fourth control switch is a normally open control switch K4. One end of the normally closed control switch K3 is connected to the first control circuit, and the other end of the normally closed control switch K3 is connected to the second power supply terminal IDET1. One end of the normally open control switch K4 is connected to the third control circuit, and the other end of the normally open control switch K4 is connected to the common ground GND.

[0010] Preferably, the third control circuit includes a transistor Q2', a diode D4', and a resistor R2', the base of the transistor Q2' is connected to one end of the resistor R2', the collector of the transistor Q2' is connected to the fourth control circuit, the emitter of the transistor Q2' is connected to the anode of the diode D4', the other end of the resistor R2' is connected to the common ground GND, and the cathode of the diode D4' is connected to the second control switch.

[0011] Preferably, the third control switch is a normally closed control switch K3', the fourth control switch is a normally closed control switch K4', one end of the normally closed control switch K3' is connected to the first control circuit, and the other end of the normally closed control switch K3' is connected to the second power supply terminal IDET1, one end of the normally closed control switch K4' is connected to the third control circuit, and the other end of the normally closed control switch K4' is connected to the second power supply terminal IDET1.

[0012] Preferably, it also includes an overcurrent protection circuit, the input end of the overcurrent protection circuit is connected to the first control switch and the second control switch, and the output end of the overcurrent protection circuit is the second power supply end IDET1; the overcurrent protection circuit includes diodes D10, D11, D12, D13, D14, resistors R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, transistor Q11, capacitors C3, C4, a voltage comparator U1 and a gain amplifier U2, the emitter of the transistor Q11 is connected to the third power supply end VCC2, and the base of the transistor Q11 is connected to The collector of transistor Q11 is connected to one end of resistor R19 and one end of resistor R20, the other end of the resistor R19 is connected to the third power supply terminal VCC2, the collector of transistor Q11 is connected to one end of resistor R21 and one end of resistor R23, the other end of resistor R20 is connected to the anode of diode D10, the cathode of diode D10 is connected to the anode of diode D11 and the anode of diode D12, the cathode of diode D11 is connected to the rising switch, the cathode of diode D12 is connected to the falling switch, the other end of resistor R21 is connected to one end of resistor R22 and one end of resistor R24, the other end of resistor R22 is connected to the non-inverting input terminal of voltage comparator U1, the positive input terminal of voltage comparator U1 and the negative input terminal of diode D12. One end of the capacitor C3, the anode of the diode D13 and one end of the resistor R15, the other end of the capacitor C3 is connected to the second common ground GND, the other end of the resistor R24 ​​is connected to the second common ground GND, the other end of the resistor R23 is connected to the inverting input terminal of the voltage comparator U1, one end of the resistor R28 and one end of the capacitor C4, the other end of the resistor R25 is connected to the output terminal of the voltage comparator U1 and one end of the resistor R26, the cathode of the diode D13 is connected to the anode of the diode D14, the cathode of the diode D14 is connected to the output terminal of the voltage comparator U1, and the other end of the resistor R26 is connected to one end of the resistor R27 and the current detection terminal The other end of the resistor R27 is connected to the second common ground GND, the other end of the resistor R28 is connected to the output end of the gain amplifier U2, one end of the resistor R29 and one end of the resistor R30, the other end of the capacitor C4 is connected to the other end of the resistor R29, the other end of the resistor R30 and one end of the resistor R31, the other end of the resistor R31 is connected to the inverting input end of the gain amplifier U2 and one end of the resistor R32, the other end of the resistor R32 is connected to the second common ground GND, the non-inverting input end of the gain amplifier U2 is connected to the first common ground GND1 and one end of the resistor R33, and the other end of the resistor R33 is connected to the second common ground GND.

[0013] A lifting device comprises a lifting mechanism, wherein the lifting mechanism comprises a motor and a push rod connected to the motor, and further comprises a low-current drive system based on relay control connected to the lifting mechanism.

[0014] By using the present invention, the following effects can be achieved:

[0015] 1. The third control switch and the fourth control switch output a small current control signal to control the motor to stop, thereby realizing the control of the motor operation through the small current control signal;

[0016] 2. The motor stops by triggering the third control switch and the fourth control switch during the movement of the motor, which has high sensitivity, reduces the wear of the motor push rod, increases the service life of the push rod, and can reduce the cost of the push rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 is a circuit diagram of embodiment 1 of the present invention;

[0019] Figure 2 is a circuit schematic diagram of an overcurrent protection circuit in Embodiment 1 of the present invention;

[0020] Figure 3 is a circuit diagram of embodiment 2 of the present invention;

[0021] Figure 4 It is a structural diagram of embodiment 3 of the present invention.

[0022] Among them, 1-lifting mechanism; 2-small current drive system based on relay control. DETAILED DESCRIPTION

[0023] The technical solutions of the present invention are further described below in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments.

[0024] Example 1

[0025] The present invention proposes a low current drive system based on relay control, such as Figure 1As shown, it includes a first control switch for controlling the reversal of the motor, a first control circuit connected to the first control switch for controlling the conduction of the circuit where the first control switch is located, and a second control circuit connected to the first control circuit for controlling the conduction of the circuit where the motor is located. It also includes a second control switch for controlling the forward rotation of the motor, a third control circuit connected to the second control switch for controlling the conduction of the circuit where the second control switch is located, and a fourth control circuit connected to the third control circuit for controlling the conduction of the circuit where the motor is located. The first control circuit is connected to the third control switch for controlling the conduction of the first control circuit through a small current signal. When the reverse rotation of the motor drives the push rod to move and trigger the third control switch, the motor stops rotating. The third control circuit is connected to the fourth control switch for controlling the conduction of the third control circuit through a small current signal. When the forward rotation of the motor drives the push rod to move and trigger the fourth control switch, the motor stops rotating.

[0026] The third control switch and the fourth control switch output a small current control signal to control the motor to stop, thereby achieving control of the motor operation through the small current control signal.

[0027] The first control circuit includes a transistor Q1, a diode D3, and a resistor R1. The base of the transistor Q1 is connected to one end of the resistor R1, the collector of the transistor Q1 is connected to the second control circuit, the emitter of the transistor Q1 is connected to the anode of the diode D3, the other end of the resistor R1 is connected to the common ground GND, and the cathode of the diode D3 is connected to the first control switch.

[0028] The second control circuit includes a relay KA1 and a diode D1. One end of the winding of the relay KA1 is connected to the first power supply terminal VCC, and the other end is connected to the first control circuit. The common contact of the relay KA1 is connected to the negative pole of the motor. The normally closed contact of the relay KA1 is connected to the common ground GND and the fourth control circuit. The normally open contact of the relay KA1 is connected to the first power supply terminal VCC and the fourth control circuit. The positive pole of the diode D1 is connected to the first control circuit, and the negative pole of the diode D1 is connected to the first power supply terminal VCC.

[0029] The third control circuit includes a transistor Q2, a diode D4, and resistors R2 and R3. The base of the transistor Q2 is connected to one end of the resistors R2 and R3, the collector of the transistor Q2 is connected to the fourth control circuit, the emitter of the transistor Q2 is connected to the anode of the diode D4, the other end of the resistor R2 is connected to the common ground GND, the other end of the resistor R3 is connected to the second power supply terminal IDET1, and the cathode of the diode D4 is connected to the second control switch.

[0030] The fourth control circuit includes a relay KA2 and a diode D2. One end of the winding of the relay KA2 is connected to the first power supply terminal VCC, and the other end is connected to the third control circuit. The common contact of the relay KA2 is connected to the positive pole of the motor, the normally closed contact of the relay KA2 is connected to the common ground GND, the normally open contact of the relay KA1 is connected to the first power supply terminal VCC, the positive pole of the diode D2 is connected to the third control circuit, and the negative pole of the diode D2 is connected to the first power supply terminal VCC.

[0031] The third control switch is a normally closed control switch K3, and the fourth control switch is a normally open control switch K4. One end of the normally closed control switch K3 is connected to the first control circuit, and the other end of the normally closed control switch K3 is connected to the second power supply terminal IDET1. One end of the normally open control switch K4 is connected to the third control circuit, and the other end of the normally open control switch K4 is connected to the common ground GND.

[0032] Initially, the circuit has a first power supply terminal, VCC, and a voltage across the motor, GND. The motor does not rotate, and the push rod does not move. The first and second control switches, K1 and K2, serve as the motor's reverse and forward rotation buttons. When pressed, the first control switch, K1, is at a low level, while the second power supply terminal, IDET1, is high. The normally closed control switch, K3, is normally closed, causing the SW1 signal to output a high level, turning on transistor Q1. Relay KA1 then begins to conduct, closing the relay. This creates a power loop across the motor, causing the motor to reverse and the push rod to descend. When the push rod reaches the lower limit switch, the normally closed control switch, K3, is triggered to open, disconnecting transistor Q1 through resistor R1. The circuit returns to its initial state, the voltage across the motor reaches GND, the motor stops rotating, and the push rod stops moving.

[0033] When the second control switch K2 is pressed, it is at a low level, the second power supply terminal IDET1 is at a high level, the normally closed control switch K4 is normally open, and the SW2 signal outputs a low level, so the transistor Q2 can be turned on, and then the relay KA2 starts to be turned on, and the relay KA2 starts to be attracted. At this time, a power supply circuit is formed at both ends of the motor, causing the motor to rotate forward and the push rod to rise. When the push rod rises to the upper limit switch, the normally closed control switch K4 is triggered to close it, and the SW2 signal is directly pulled down to the common ground GND, thereby disconnecting the transistor Q2, and the circuit returns to its initial state. The voltage at both ends of the motor is GND, the motor stops rotating, and the push rod stops moving.

[0034] The above-mentioned SW1 signal and SW2 signal are small current signals that can control the conduction and disconnection of transistors Q1 and Q2, thereby achieving control of motor stoppage, which is safer and more reliable than directly disconnecting the motor line in the existing technology.

[0035] The motor is stopped by triggering the third control switch and the fourth control switch during the movement of the motor, which has high sensitivity, reduces the wear of the motor push rod, increases the service life of the push rod, and can reduce the cost of the push rod.

[0036] As a further option of this embodiment, the system further includes an overcurrent protection circuit, the input end of the overcurrent protection circuit is connected to the first control switch and the second control switch, and the output end of the overcurrent protection circuit is the second power supply end IDET1.

[0037] like Figure 2As shown, the overcurrent protection circuit includes diodes D10, D11, D12, D13, D14, resistors R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, a transistor Q11, capacitors C3, C4, a voltage comparator U1, and a gain amplifier U2, an emitter of the transistor Q11 is connected to the third power supply terminal VCC2, a base of the transistor Q11 is connected to one end of the resistor R19 and one end of the resistor R20, the other end of the resistor R19 is connected to the third power supply terminal VCC2, a collector of the transistor Q11 is connected to one end of the resistor R21 and one end of the resistor R23, the other end of the resistor R20 is connected to the positive electrode of the diode D10, the negative electrode of the diode D10 is connected to the positive electrode of the diode D11 and the positive electrode of the diode D12, the negative electrode of the diode D11 is connected to the up switch, the negative electrode of the diode D12 is connected to the down switch, the other end of the resistor R21 is connected to one end of the resistor R22 and one end of the resistor R24, the other end of the resistor R22 is connected to the positive input terminal of the voltage comparator U1, one end of the capacitor C3, the positive electrode of the diode D13, and one end of the resistor R15, the other end of the capacitor C3 is connected to the second common ground GND, the other end of the resistor R24 is connected to the second common ground GND, the other end of the resistor R23 is connected to the inverting input terminal of the voltage comparator U1, one end of the resistor R28, and one end of the capacitor C4, the other end of the resistor R25 is connected to the output terminal of the voltage comparator U1 and one end of the resistor R26, the negative electrode of the diode D13 is connected to the positive electrode of the diode D14, the negative electrode of the diode D14 is connected to the output terminal of the voltage comparator U1, the other end of the resistor R26 is connected to one end of the resistor R27 and the current detection terminal, the other end of the resistor R27 is connected to the second common ground GND, the other end of the resistor R28 is connected to the output terminal of the gain amplifier U2, one end of the resistor R29, and one end of the resistor R30, the other end of the capacitor C4 is connected to the other end of the resistor R29, the other end of the resistor R30, and one end of the resistor R31, the other end of the resistor R31 is connected to the inverting input terminal of the gain amplifier U2 and one end of the resistor R32, the other end of the resistor R32 is connected to the second common ground GND, the positive input terminal of the gain amplifier U2 is connected to the first common ground GND1 and one end of the resistor R33, the other end of the resistor R33 is connected to the second common ground GND.

[0038] When the first control switch K1 is pressed, diodes D10, D11, and D12 prevent the first control switch K1 from being affected and debounce the key. Resistors R19 and R20 begin to divide the voltage, turning on transistor Q11 and generating a voltage VCC2-1. This activates the overcurrent protection circuit. The voltage is then divided and fed back through resistors R21, R22, R24, capacitor C3, resistor R25, and diodes D13 and D14 to form the positive-phase voltage for voltage comparator U1. This completes the motor circuit, and a motor current sampling voltage is generated at the first common ground GND1 by sampling resistor R33. After being amplified by gain amplifier comparator U2, the sampling voltage is compared with the positive-phase voltage of voltage comparator U1. The overcurrent protection voltage at current detection terminal IDET1 is high when the motor operating current is within the normal range and low when it exceeds the normal range. A low-level output stops the motor from operating, thus providing overcurrent protection. Similarly, when the second control switch K2 is pressed, the current detection terminal operates in the same manner and will not be further described.

[0039] Example 2

[0040] like Figure 3 As shown, the difference from the first embodiment is that the third control circuit includes a transistor Q2', a diode D4', and a resistor R2'. The base of the transistor Q2' is connected to one end of the resistor R2', the collector of the transistor Q2' is connected to the fourth control circuit, the emitter of the transistor Q2' is connected to the anode of the diode D4', the other end of the resistor R2' is connected to the common ground GND, and the cathode of the diode D4' is connected to the second control switch. The third control switch is a normally closed control switch K3', and the fourth control switch is a normally closed control switch K4'. One end of the normally closed control switch K3' is connected to the first control circuit, and the other end of the normally closed control switch K3' is connected to the second power supply terminal IDET1. One end of the normally closed control switch K4' is connected to the third control circuit, and the other end of the normally closed control switch K4' is connected to the second power supply terminal IDET1.

[0041] The fourth control switch is set to a normally closed control switch K4 ′ and the corresponding circuit connection is changed, but its working principle is the same as that of the first embodiment, so it will not be described again.

[0042] Example 3

[0043] Real-time Example 3 proposes a lifting device, such as Figure 4 As shown, it includes a lifting mechanism 1, which includes a motor and a push rod connected to the motor, and also includes a low-current drive system 2 based on relay control as described in the above embodiment 1 or embodiment 2 connected to the lifting mechanism.

[0044] The lifting device can be a lifting table, a lifting chair or the like.

[0045] Those skilled in the art may make various modifications or additions to the described embodiments or replace them with similar methods without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A low current drive system based on relay control, characterized in that: The invention comprises a first control switch for controlling reverse rotation of the motor, a first control circuit connected to the first control switch for controlling conduction of a circuit in which the first control switch is located, and a second control circuit connected to the first control circuit for controlling conduction of a circuit in which the motor is located. The invention also comprises a second control switch for controlling forward rotation of the motor, a third control circuit connected to the second control switch for controlling conduction of a circuit in which the second control switch is located, and a fourth control circuit connected to the third control circuit for controlling conduction of a circuit in which the motor is located. The first control circuit is connected to the third control switch for controlling conduction of the first control circuit through a small current signal. When reverse rotation of the motor drives the push rod to move and trigger the third control switch, the motor stops rotating. The third control circuit is connected to the fourth control switch for controlling conduction of the third control circuit through a small current signal. When forward rotation of the motor drives the push rod to move and trigger the fourth control switch, the motor stops rotating. The device also includes an overcurrent protection circuit, wherein the input end of the overcurrent protection circuit is connected to the first control switch and the second control switch, and the output end of the overcurrent protection circuit is the second power supply end IDET1; the overcurrent protection circuit includes diodes D10, D11, D12, D13, D14, resistors R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, a transistor Q11, capacitors C3, C4, a voltage comparator U1 and a gain amplifier U2, the emitter of the transistor Q11 is connected to the third power supply end VCC2, and the base of the transistor Q11 is connected to the resistor One end of R19 and one end of resistor R20, the other end of the resistor R19 is connected to the third power supply terminal VCC2, the collector of transistor Q11 is connected to one end of resistor R21 and one end of resistor R23, the other end of the resistor R20 is connected to the anode of diode D10, the cathode of diode D10 is connected to the anode of diode D11 and the anode of diode D12, the cathode of diode D11 is connected to the rising switch, and the cathode of diode D12 is connected to the falling switch, the other end of the resistor R21 is connected to one end of resistor R22 and one end of resistor R24, and the other end of the resistor R22 is connected to the non-inverting input terminal of voltage comparator U1 and capacitor C 3, the anode of the diode D13 and one end of the resistor R25, the other end of the capacitor C3 is connected to the second common ground GND, the other end of the resistor R24 ​​is connected to the second common ground GND, the other end of the resistor R23 is connected to the inverting input terminal of the voltage comparator U1, one end of the resistor R28 and one end of the capacitor C4, the other end of the resistor R25 is connected to the output terminal of the voltage comparator U1 and one end of the resistor R26, the cathode of the diode D13 is connected to the anode of the diode D14, the cathode of the diode D14 is connected to the output terminal of the voltage comparator U1, the other end of the resistor R26 is connected to one end of the resistor R27 and the current detection terminal, The other end of the resistor R27 is connected to the second common ground GND, the other end of the resistor R28 is connected to the output end of the gain amplifier U2, one end of the resistor R29 and one end of the resistor R30, the other end of the capacitor C4 is connected to the other end of the resistor R29, the other end of the resistor R30 and one end of the resistor R31, the other end of the resistor R31 is connected to the inverting input end of the gain amplifier U2 and one end of the resistor R32, the other end of the resistor R32 is connected to the second common ground GND, the non-inverting input end of the gain amplifier U2 is connected to the first common ground GND1 and one end of the resistor R33, and the other end of the resistor R33 is connected to the second common ground GND.

2. The low current drive system based on relay control according to claim 1, characterized in that: The first control circuit includes a transistor Q1, a diode D3, and a resistor R1. The base of the transistor Q1 is connected to one end of the resistor R1, the collector of the transistor Q1 is connected to the second control circuit, the emitter of the transistor Q1 is connected to the anode of the diode D3, the other end of the resistor R1 is connected to the common ground GND, and the cathode of the diode D3 is connected to the first control switch.

3. The low current drive system based on relay control according to claim 1, characterized in that: The second control circuit includes a relay KA1 and a diode D1. One end of the winding of the relay KA1 is connected to the first power supply terminal VCC, and the other end is connected to the first control circuit. The common contact of the relay KA1 is connected to the negative pole of the motor. The normally closed contact of the relay KA1 is connected to the common ground GND and the fourth control circuit. The normally open contact of the relay KA1 is connected to the first power supply terminal VCC and the fourth control circuit. The positive pole of the diode D1 is connected to the first control circuit, and the negative pole of the diode D1 is connected to the first power supply terminal VCC.

4. The low current drive system based on relay control according to claim 1, characterized in that: The third control circuit includes a transistor Q2, a diode D4, and resistors R2 and R3. The base of the transistor Q2 is connected to one end of the resistors R2 and R3, the collector of the transistor Q2 is connected to the fourth control circuit, the emitter of the transistor Q2 is connected to the anode of the diode D4, the other end of the resistor R2 is connected to the common ground GND, the other end of the resistor R3 is connected to the second power supply terminal IDET1, and the cathode of the diode D4 is connected to the second control switch.

5. The low current drive system based on relay control according to claim 1, characterized in that: The fourth control circuit includes a relay KA2 and a diode D2. One end of the winding of the relay KA2 is connected to the first power supply terminal VCC, and the other end is connected to the third control circuit. The common contact of the relay KA2 is connected to the positive pole of the motor, the normally closed contact of the relay KA2 is connected to the common ground GND, the normally open contact of the relay KA1 is connected to the first power supply terminal VCC, the positive pole of the diode D2 is connected to the third control circuit, and the negative pole of the diode D2 is connected to the first power supply terminal VCC.

6. The low current drive system based on relay control according to any one of claims 1 to 5, characterized in that: The third control switch is a normally closed control switch K3, and the fourth control switch is a normally open control switch K4. One end of the normally closed control switch K3 is connected to the first control circuit, and the other end of the normally closed control switch K3 is connected to the second power supply terminal IDET1. One end of the normally open control switch K4 is connected to the third control circuit, and the other end of the normally open control switch K4 is connected to the common ground GND.

7. The low current drive system based on relay control according to claim 1, characterized in that: The third control circuit includes a transistor Q2', a diode D4', and a resistor R2'. The base of the transistor Q2' is connected to one end of the resistor R2', the collector of the transistor Q2' is connected to the fourth control circuit, the emitter of the transistor Q2' is connected to the anode of the diode D4', the other end of the resistor R2' is connected to the common ground GND, and the cathode of the diode D4' is connected to the second control switch.

8. The low current drive system based on relay control according to claim 7, characterized in that: The third control switch is a normally closed control switch K3', and the fourth control switch is a normally closed control switch K4'. One end of the normally closed control switch K3' is connected to the first control circuit, and the other end of the normally closed control switch K3' is connected to the second power supply terminal IDET1. One end of the normally closed control switch K4' is connected to the third control circuit, and the other end of the normally closed control switch K4' is connected to the second power supply terminal IDET1.

9. A lifting device, comprising a lifting mechanism, wherein the lifting mechanism comprises a motor and a push rod connected to the motor, wherein: It also includes a low-current drive system based on relay control as described in any one of claims 1 to 8 connected to the lifting mechanism.

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