Furniture electric push rod control circuit
By using micro switch control relays in furniture electric push rod control circuit, combining transistors and children's lock switches, the problem of micro switches withstand excessive current damage is solved, and the dual improvement of circuit safety and cost is achieved.
Patent Information
- Application Number
- CN202323482423.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-20
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2033-12-20
AI Technical Summary
In the existing furniture electric push rod control circuit, the micro switches bear the risk of damage caused by excessive current, which is particularly prominent in products with heavy loads.
The relay is controlled by a micro switch, so that the motor operating current does not flow through the micro switch, and a transistor and a child lock switch are introduced into the circuit to amplify the control signal and increase safety, while a parallel DC motor is used to increase thrust.
Reduces the risk of damage to micro switches, simplifies circuit structure, reduces costs, and improves product safety.
Smart Images
Figure CN222215558U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of electric push rod control, and in particular to a furniture electric push rod control circuit. Background Art
[0002] The angle adjustment and lifting functions of existing furniture products are mostly achieved by extending and contracting electric push rods, and the rotation of the motor inside the electric push rod is often driven by a hand controller or a controller. The hand controller has a simple circuit and low cost. The internal core component is a micro switch, which conducts the voltage across the motor to achieve power supply and rotation of the motor. However, this method will cause current to flow through the micro switch itself, which has certain requirements on the current carrying capacity of the micro switch. When the load is heavier, the power required by the electric push rod is relatively high, which will generate a relatively large current and pose a risk of damage to the micro switch. Utility Model Content
[0003] The utility model aims to provide a control circuit for an electric push rod of furniture, which controls a relay through a micro switch, and controls a motor through the relay, so that the working current of the motor will not flow through the micro switch.
[0004] To achieve the above purpose, the technical solution of the utility model is:
[0005] A furniture electric push rod control circuit, the circuit comprising: an external power supply, a DC motor, micro switches W2, W3, relays K1, K2, transistors Q1, Q2;
[0006] The common end of the relay K1 is connected to the positive pole of the DC motor, the common end of the relay K2 is connected to the negative pole of the DC motor, the normally closed ends of the relays K1 and K2 are both connected to GND, the normally open ends of the relays K1 and K2 are both connected to the positive pole of the external power supply, one end of the coil of the relay K1 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W2 through the transistor Q1, one end of the coil of the relay K2 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W3 through the transistor Q2, and the active ends of the micro switches W2 and W3 are both connected to the external power supply.
[0007] The micro switch is used to control the closing of the relay so that the motor operating current does not flow through the micro switch, reducing the risk of damage to the micro switch.
[0008] Preferably, the transistors Q1 and Q2 are both NPN transistors, the collector of the transistor Q1 is connected to the coil of the relay K1, and the collector of the transistor Q2 is connected to the coil of the relay K2;
[0009] The emitters of the transistors Q1 and Q2 are both connected to GND, the base of the transistor Q1 is connected to the fixed end of the micro switch W2, and the base of the transistor Q2 is connected to the fixed end of the micro switch W3.
[0010] By directly adding transistors between the micro switch and the relay, on the one hand, the control signal can be amplified to drive the relay, and on the other hand, the adverse effect of the reverse electromotive force generated by the relay during operation on the control circuit can be reduced.
[0011] Preferably, the active ends of the micro switches W2 and W3 include a normally open end and a normally closed end, the normally closed ends of the micro switches W2 and W3 are both connected to GND, and the normally open ends of the micro switches W2 and W3 are both connected to the external power supply.
[0012] By grounding the normally closed end of the micro switch, the safety of the circuit device can be further increased.
[0013] Preferably, a child lock switch W1 is also connected between the external power supply and the normally open ends of the micro switches W2 and W3.
[0014] By adding a child lock switch, special tools are needed to press the switch during use, and then it can be controlled by the micro switch, which can prevent it from being touched and pressed by children.
[0015] Preferably, the DC motor includes a DC motor M1 and a DC motor M2, and the DC motor M1 and the DC motor M2 are connected in parallel.
[0016] By having two motors working simultaneously, the thrust of the push rod can be increased, which can cope with more usage scenarios with relatively large loads.
[0017] Preferably, a varistor ZNR1 is connected in parallel at both ends of the DC motor.
[0018] The varistor can be used to reduce the electromotive force generated when the motor is in motion, thereby reducing the impact of the transient voltage generated when the motor's motion state switches on the circuit.
[0019] Preferably, a first resistor R1 is connected in series between the base of the transistor Q1 and the micro switch W2.
[0020] Through the first resistor R1 , during the switching process of the micro switch, the base level of the transistor Q1 can be normally stabilized at a low level to reduce the risk of damage to the transistor Q1 due to excessive current.
[0021] Preferably, a second resistor R2 is connected in series between the base of the transistor Q2 and the micro switch W3.
[0022] Through the first resistor R2, during the switching process of the micro switch, the base level of the transistor Q2 can be normally stabilized at a low level to reduce the risk of damage to the transistor Q2 due to excessive current.
[0023] Compared with the prior art, the beneficial effects of the utility model are: the motor is driven by directly controlling the closing and closing of the relay through the microswitch, and under the action of the transistor, the current of the electric push rod passes through the relay instead of the microswitch, thereby reducing the possibility of damage to the microswitch due to overcurrent; in addition, by directly controlling the closing of the relay through the microswitch, there is no need to use a chip for driving, making the circuit simpler and the cost lower; in addition, the child lock switch can reduce accidental touch by children, thereby increasing the safety of the product to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is the control circuit schematic diagram of the utility model;
[0025] Figure 2 It is a schematic diagram of the product push rod control provided in the embodiment of the present application;
[0026] Figure 3 This is a circuit wiring diagram of the push rod control provided in the embodiment of the present application. DETAILED DESCRIPTION
[0027] This embodiment provides a furniture electric push rod control circuit, see Figure 1 , including an external power supply, a DC motor, micro switches W2, W3, relays K1, K2, and transistors Q1, Q2.
[0028] Among them, the common end of relay K1 is connected to the positive pole of the DC motor, the common end of relay K2 is connected to the negative pole of the DC motor, the normally closed ends of relays K1 and K2 are connected to GND, the normally open ends of relays K1 and K2 are connected to the positive pole of the external power supply, one end of the coil of relay K1 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W2 through the transistor Q1. One end of the coil of relay K2 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W3 through the transistor Q2. The active ends of the micro switches W2 and W3 are both connected to the external power supply.
[0029] Furthermore, both transistors Q1 and Q2 are NPN transistors, the collector of transistor Q1 is connected to the coil of relay K1, and the collector of transistor Q2 is connected to the coil of relay K2.
[0030] The emitters of transistors Q1 and Q2 are both connected to GND, the base of transistor Q1 is connected to the fixed end of micro switch W2, and the base of transistor Q2 is connected to the fixed end of micro switch W3.
[0031] Furthermore, the active ends of the micro switches W2 and W3 include a normally open end and a normally closed end. The normally closed ends of the micro switches W2 and W3 are both connected to GND, and the normally open ends of the micro switches W2 and W3 are both connected to an external power supply.
[0032] Furthermore, a child lock switch W1 is connected between the external power supply and the normally open ends of the micro switches W2 and W3.
[0033] Furthermore, the DC motor includes a DC motor M1 and a DC motor M2, and the DC motor M1 and the DC motor M2 are connected in parallel.
[0034] Furthermore, a varistor ZNR1 is connected in parallel at both ends of the DC motor.
[0035] Furthermore, a first resistor R1 is connected in series between the base of the transistor Q1 and the micro switch W2.
[0036] Furthermore, a second resistor R2 is connected in series between the base of the transistor Q2 and the micro switch W3.
[0037] The working principle of the utility model is as follows:
[0038] Take the push rod drive of the bed frame as an example, see Figure 2 , use the hand controller to control the left and right electric push rods to open and lift the bed frame. The space inside the bed box can be used for storage. After the items are placed, the hand controller can also be used to control the left and right electric push rods to retract and lay the bed frame flat.
[0039] See also Figure 3 The hand controller controls the two micro switches W2 and W3 and a child lock switch W1 to control the closing and disconnection of relays K1 and K2 in the control box, thereby driving the electric push rod. The electric push rod uses a DC motor inside, which can be driven to rotate forward and reverse by switching the positive and negative voltages of the DC motor. The two electric push rods are in parallel and rise and fall at the same time.
[0040] When facing products with heavier loads, greater thrust is often required, so two electric push rods are used to increase the overall thrust. However, the current of the two electric push rods when working can easily exceed the current that the hand controller can withstand. Therefore, relays are used for indirect drive, and the motor current only flows through the relay to ensure that the micro switch and related wiring harness on the hand controller will not be damaged due to overcurrent.
[0041] Specifically, see Figure 1 , micro switches W2, W3 and relays K1, K2 can all be regarded as single-pole double-throw switches, including a fixed end (common end), represented by contact 1, and an active end. The active end can be divided into a normally closed end and a normally open end, represented by contact 2 and contact 3 respectively. The child lock switch W1 can be regarded as a single-pole single-throw switch.
[0042] When the child lock switch W1 is disconnected, if the micro switches W2 and W3 are both in the disconnected state, that is, their contacts 1 and 2 are connected, at this time, the base of the transistor Q1 is connected to GND through the first resistor R1 and the micro switch W2. Similarly, the base of the transistor Q2 is connected to GND through the second resistor R2 and the micro switch W3.
[0043] If the micro switches W2 and W3 are both closed, that is, their contacts 1 and 3 are connected, because the child lock switch W1 is not closed, the bases of the transistors Q1 and Q2 are both suspended, and the base level of the transistors is normally stabilized at a low level.
[0044] At the same time, because W1 is not closed, transistors Q1 and Q2 are in the cut-off state because no current passes through them. At this time, relays K1 and K2 are in the disconnected state, that is, contacts 1 and 2 of relays K1 and K2 are connected, so the positive and negative poles of DC motors M1 and M2 are connected to GND, that is, when the child lock W1 is in the disconnected state, the motors are in the stopped state.
[0045] When the child lock switch W1 is closed, the micro switch W2 is closed, and W3 is disconnected, that is, the contacts 1 and 3 of the micro switch W2 are connected, and the contacts 1 and 2 of the micro switch W3 are connected, then the base of the transistor Q1 is connected to the external power supply through the first resistor R1, so there is a voltage difference between the base and the emitter of the transistor Q1, and the transistor Q1 is turned on. At this time, the relay K1 will be attracted, causing the contacts 1 and 3 of the relay K1 to be connected. At this time, the positive pole of the motor is connected to the external power supply through the relay K1; and the transistor Q2 is still in the cut-off state, that is, the negative pole of the DC motor is connected to GND through the relay K2, so the DC motor rotates forward, the electric push rod opens, and the bed frame rises.
[0046] Similarly, when the microswitch W3 is closed and W2 is disconnected, the transistor Q1 is in the cut-off state, and the positive pole of the motor is connected to GND through the relay K1; the transistor Q2 is turned on, and the relay K2 is energized, causing the contacts 1 and 3 of the relay K2 to be connected, that is, the negative pole of the motor is connected to the external power supply through the relay K2, so the motor reverses, the electric push rod contracts, and the bed frame descends.
[0047] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the principles of the present application should be included in the protection scope of the present application.
Claims
1. A furniture electric push rod control circuit, characterized in that: The circuit includes an external power supply, a DC motor, micro switches W2, W3, relays K1, K2, and transistors Q1, Q2; The common end of the relay K1 is connected to the positive pole of the DC motor, the common end of the relay K2 is connected to the negative pole of the DC motor, the normally closed ends of the relays K1 and K2 are both connected to GND, the normally open ends of the relays K1 and K2 are both connected to the positive pole of the external power supply, one end of the coil of the relay K1 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W2 through the transistor Q1, one end of the coil of the relay K2 is connected to the positive pole of the external power supply, and the other end is connected to the fixed end of the micro switch W3 through the transistor Q2, and the active ends of the micro switches W2 and W3 are both connected to the external power supply.
2. A furniture electric push rod control circuit according to claim 1, characterized in that: The transistors Q1 and Q2 are both NPN transistors, the collector of the transistor Q1 is connected to the coil of the relay K1, and the collector of the transistor Q2 is connected to the coil of the relay K2; The emitters of the transistors Q1 and Q2 are both connected to GND, the base of the transistor Q1 is connected to the fixed end of the micro switch W2, and the base of the transistor Q2 is connected to the fixed end of the micro switch W3.
3. A furniture electric push rod control circuit according to claim 1, characterized in that: The active ends of the micro switches W2 and W3 include a normally open end and a normally closed end. The normally closed ends of the micro switches W2 and W3 are both connected to GND, and the normally open ends of the micro switches W2 and W3 are both connected to the external power supply.
4. A furniture electric push rod control circuit according to claim 3, characterized in that: A child lock switch W1 is also connected between the external power supply and the normally open ends of the micro switches W2 and W3.
5. A furniture electric push rod control circuit according to claim 1, characterized in that: The DC motor includes a DC motor M1 and a DC motor M2, and the DC motor M1 and the DC motor M2 are connected in parallel.
6. A furniture electric push rod control circuit according to claim 1, characterized in that: A varistor ZNR1 is also connected in parallel at both ends of the DC motor.
7. A furniture electric push rod control circuit according to claim 1, characterized in that: A first resistor R1 is connected in series between the base of the transistor Q1 and the micro switch W2.
8. The electric push rod control circuit for furniture according to claim 1, characterized in that: A second resistor R2 is connected in series between the base of the transistor Q2 and the micro switch W3.