Latch switch circuit
By using thyristors in the latch switch circuit, the problem of adding power paths and starting button safety hazards in the prior art self-locking circuit is solved, and the self-holding function of the relay is realized, reducing costs and improving safety.
Patent Information
- Application Number
- CN202411702463.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-18
AI Technical Summary
In the prior art, when implementing a self-locking circuit, it is necessary to add a power path, resulting in an increase in the cost of the relay. After a long period of use, the start button may be damaged, which poses a safety hazard.
By setting a thyristor in the latch switch circuit, using its control characteristics, the state of the circuit can be maintained even if the first switch and the second switch are not continuously turned on, and the self-holding of the relay can be achieved.
Reduces development costs, improves operator safety, and can still work effectively when used in low voltage environments, avoiding complex programming of digital logic chips or microprocessors.
Smart Images
Figure CN119650357A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a switch circuit, and in particular to a latch switch circuit. Background Art
[0002] When an operator starts or stops industrial electrical equipment, generally speaking, they use different buttons, one is a start button configured to start the operation of the industrial electrical equipment, and the other is a stop button configured to stop the operation of the industrial electrical equipment.
[0003] In order to keep the circuit running after the start switch is pressed, the prior art uses a self-locking circuit. The self-locking circuit includes a start button, a stop button, a relay contact and a relay, wherein the relay contact is a normally open contact, the start button and the normally open contact of the relay are connected in parallel, and one of the contacts on the same side of the start button and the relay contact is connected in series with the stop button, while the other contact on the same side of the start button and the relay contact is connected in series with the relay. When the start button is pressed, the relay contact will close to achieve self-locking, so that when the operator releases the start button, power can still be provided to the relay through the closed relay contact without the operator having to continue pressing the start button.
[0004] However, the prior art requires an additional power path for the self-locking circuit to achieve self-locking by setting the relay contacts, which increases the cost of the relay. In addition, the start button is usually directly connected to a 220-volt strong current in the self-locking circuit. After the start button is set for a long time, if the start button is damaged, there may be a safety hazard.
[0005] In addition, the prior art also has a power switch control in a weak current circuit controller, which is mainly implemented in a dedicated digital logic chip or a microcontroller in a program manner.
[0006] However, the method of power switch control using a low-current circuit controller is not only more complicated in circuit, but also requires providing a specific 5V or 3.3V voltage to the digital logic chip or microcontroller. This will increase the cost. In addition, the anti-interference performance will not be very good when working in an industrial field environment (such as: CMOS type digital logic chip), and it is easy to malfunction due to interference. Summary of the invention
[0007] In view of the above-mentioned deficiencies in the prior art, the main purpose of the present application is to provide a latching switch circuit, which, through the setting of thyristors, can make the state of the relay in the circuit self-maintained, thereby improving the safety of operators and significantly reducing development costs.
[0008] In order to achieve the above purpose, the main technical means adopted by this application is to make the latch switch circuit include:
[0009] An input terminal configured to connect to a power source;
[0010] A first switch connected to the input terminal;
[0011] A second switch connected to the input terminal;
[0012] A first current-controlled switch, comprising a first control end, a first controlled end, and a second controlled end, wherein the first control end is connected to the first switch, and the first controlled end is connected to the input end;
[0013] a relay connected to the second controlled end;
[0014] a second current-controlled switch having a second control end, a third controlled end and a fourth controlled end, wherein the second control end is connected to the input end, and the third controlled end is connected to the relay;
[0015] A common ground terminal is connected to the second switch and the fourth controlled terminal.
[0016] Preferably, when the first switch is turned on, the first control end receives the power supply from the input end through the first switch, the first control end controls the first controlled end and the second controlled end to be conductive with each other, and the relay receives the power supply through the first current control switch, so that the relay generates magnetic force according to the power supply.
[0017] Preferably, when the second switch is turned on, the second control terminal is connected to the common ground terminal through the second switch, the second control terminal controls the third controlled terminal and the fourth controlled terminal to be cut off from each other, and the relay stops providing the magnetic force.
[0018] Preferably, the latch switch circuit comprises:
[0019] The unidirectional conducting element is connected in parallel with the relay.
[0020] Preferably, the first current control switch includes a gate terminal, a first anode terminal and a first cathode terminal; the second current control switch includes a base terminal, a collector terminal and an emitter terminal; and the unidirectional conductive element includes a second anode terminal and a second cathode terminal.
[0021] Preferably, the latch switch circuit further comprises:
[0022] a first impedance element, arranged between the input end and the first switch, and between the input end and the second switch;
[0023] The second impedance element is arranged between the first impedance element and the second switch.
[0024] Preferably, the impedance value of the first impedance element is smaller than the impedance value of the second impedance element.
[0025] Preferably, the latch switch circuit further comprises:
[0026] The third impedance component is arranged between the gate terminal and the second cathode terminal.
[0027] Preferably, the first pin of the first impedance element is connected to the input end, and the first switch, the second switch and the first pin of the second impedance element are respectively connected to the second pin of the first impedance element; the gate terminal is connected to the second pin of the first switch and the first pin of the third impedance element; the first anode terminal is connected to the input end and the first pin of the first impedance element; the first pin of the relay is connected to the first cathode terminal, the second cathode terminal and the second pin of the third impedance element; the base terminal is connected to the second pin of the second impedance element, the collector terminal is connected to the second pin of the relay and the second anode terminal, and the emitter terminal is connected to the common ground terminal.
[0028] Through the above structure, by setting a thyristor in the latch switch circuit of the present application, through the control characteristics of the thyristor, even if the first switch and the second switch have passed the previous circuit state and the first switch and the second switch are not continuously turned on, the circuit state can still be maintained. In this way, it can be used in a low-voltage environment while maintaining the circuit state, thereby improving the safety of the operator, and the self-maintaining function can be achieved without the need to design a complex program through a digital logic chip or a microprocessor, which greatly reduces the development cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0030] Figure 1 is a block diagram of the latch switch circuit of the present application.
[0031] Figure 2 It is a block diagram of a specific embodiment of the latch switch circuit of the present application. DETAILED DESCRIPTION
[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0033] Figure 1 is a block diagram of the latch switch circuit of the present application. Figure 1 As shown, the latch switch circuit 10 of the present application includes an input terminal Input, a first switch 12, a second switch 13, a first current control switch 14, a relay 15, a second current control switch 16 and a common ground terminal G. The input terminal Input is configured to be connected to a power supply. The first switch 12 and the second switch 13 are connected to the input terminal Input. The first current control switch 14 has a first control terminal 141, a first controlled terminal 142 and a second controlled terminal 143, the first control terminal 141 is connected to the first switch 12, and the first controlled terminal 142 is connected to the input terminal Input. The relay 15 is connected to the second controlled terminal 143. The second current control switch 16 has a second control terminal 161, a third controlled terminal 162 and a fourth controlled terminal 163. The second control terminal 161 is connected to the input terminal Input, and the second controlled terminal 162 is connected to the relay 15. The common ground terminal G is connected to the second switch 13 and the fourth controlled terminal 163.
[0034] In detail, when the first switch 12 and the second switch 13 are not turned on, the second control end 161 of the second current control switch 16 receives power from the input end Input, so that the second current control switch 16 is controlled to be turned on. Then, when the first switch 12 is turned on in response to the operation of the operator (such as pressing), the first control end 141 receives power from the input end Input through the first switch 12. When the first control end 141 receives power, the first controlled end 142 and the second controlled end 143 are connected to each other corresponding to the control of the first control end 141, so that the power can be continuously transmitted to the relay 15 through the first current control switch 14. After the relay 15 receives the power, the relay 15 can generate magnetic force according to the power. At this time, since the first current control switch 14 has been turned on, even if the operator turns off the first switch 12 (such as not pressing), it will not change the relay 15 to continue to provide magnetic force.
[0035] When the operator wants to stop the relay 15 from outputting magnetic force, the operator controls (e.g., presses) the second switch 13 to turn on. Then, after the second switch 13 is turned on, the second control end 161 of the second current control switch 16 is connected to the common ground end G through the second switch 13 to control the third controlled end 162 and the fourth controlled end 163 to be cut off from each other. Specifically, when the second control end 161 of the second current control switch 16 receives a low potential (e.g., zero potential) from the common ground end G through the second switch 13, the third controlled end 162 and the fourth controlled end 163 are cut off (i.e., not conducting). At this time, the power received by the third controlled end 162 of the second current control switch 16 from the relay 15 will be cut off between the third controlled end 162 and the fourth controlled end 163, and the power cannot flow through the second current control switch 16, so that the relay 15 cannot form a loop with the common ground end G, resulting in the first current control switch 14 being cut off. In this way, the relay 15 will stop providing magnetic force.
[0036] In some embodiments, the latch switch circuit 10 includes a unidirectional conductive element 17. The unidirectional conductive element 17 is connected in parallel with the relay 15. By setting the unidirectional conductive element 17, when the second switch 13 is turned on, the second current control switch 16 is turned off, and the current flowing through the relay 15 can be continued through the unidirectional conductive element 17 to prevent the relay 15 from generating self-inductive high voltage.
[0037] In order to more clearly illustrate the connection relationship between the various components of the present application, the endpoints connecting each component to other components are respectively described as a first pin and a second pin. The first pin can be used as the inflow end of the power supply of each component, and the second pin can be used as the outflow end of the power supply of each component.
[0038] Figure 2 is a block diagram of a specific embodiment of the latch switch circuit of the present application. Figure 1 and Figure 2 As shown, the first control terminal 141 corresponds to the gate terminal Gate, the first controlled terminal 142 corresponds to the first anode terminal A1, and the second controlled terminal 143 corresponds to the first cathode terminal K1. The second control terminal 161 corresponds to the base terminal B, the third controlled terminal 162 corresponds to the collector terminal C, and the fourth controlled terminal 163 corresponds to the emitter terminal E, and the unidirectional conductive element 17 includes a second anode terminal A2 and a second cathode terminal K2.
[0039] like Figure 2 As shown, in some embodiments, the latch switch circuit 10 further includes a first impedance element R1 and a second impedance element R2. The first impedance element R1 is disposed between the input terminal Input and the first switch 12 and between the input terminal Input and the second switch 13. The second impedance element R2 is disposed between the first impedance element 112 and the second switch 13.
[0040] In some embodiments, the impedance value of the first impedance element 112 is smaller than the impedance value of the second impedance element 113 .
[0041] In some embodiments, the latch switch circuit 10 further includes a third impedance element 18. The third impedance element 18 is disposed between the gate terminal Gate of the first current control switch 14 and the second cathode terminal K2 of the unidirectional conductive element 17. By disposing the third impedance element 17, the interference signal is bypassed, and the anti-interference performance of the latch switch circuit 10 can be improved, thereby preventing various interference signals such as electrostatic induction or electromagnetic induction of operators or external environments from triggering the gate terminal Gate and causing erroneous conduction.
[0042] In detail, the first pin of the first impedance element R1 is connected to the input terminal Input, and the first pins of the first switch 12, the second switch 13 and the second impedance element R2 are respectively connected to the second pin of the first impedance element R1. The gate terminal Gate of the first current control switch 14 is connected to the second pin of the first switch 12 and the first pin of the third impedance element R3. The first anode terminal A1 of the first current control switch 14 is connected to the input terminal Input and the first pin of the first impedance element R1. The first pin of the relay 15 is connected to the first cathode terminal K1 of the first current control switch 14, the second cathode terminal K2 of the unidirectional conductive element 17 and the second pin of the third impedance element R3. The base terminal B of the second current control switch 16 is connected to the second pin of the second impedance element R2, the collector terminal C of the second current control switch 16 is connected to the second pin of the relay 15 and the second anode terminal A2 of the unidirectional conductive element 17, and the emitter terminal E of the second current control switch 16 is connected to the common ground terminal G.
[0043] When the input terminal Input of the latch switch circuit 10 of the present application is connected to the power supply Vcc, when the first switch 12 and the second switch 13 are in the cut-off state (i.e., not turned on or off), the current is transmitted to the base B of the second current control switch 16 through the first impedance component R1 and the second impedance component R3, and since the gate terminal Gate of the first current control switch 14 does not receive the control signal (i.e., does not receive the current), the first current control switch 14 is in the cut-off state (i.e., not turned on or off). At this time, the relay 15 cannot form a loop through the first current control switch 14, the second current control switch 16 and the common ground terminal G, so that the relay 15 has no current. When the first switch 12 is turned on, the gate terminal Gate of the first current control switch 14 obtains a control signal to control the conduction between the first anode terminal A1 and the first cathode terminal K1 of the first current control switch 14, and the current is transmitted to the base B of the second current control switch 16 through the first impedance component R1 and the second impedance component R3, and the conduction between the collector terminal C and the emitter terminal E of the second current control switch 16 is controlled. At this time, the relay 15 forms a loop through the first current control switch 14, the second current control switch 16 and the common ground terminal G, so that the current flows through the relay 15 and generates magnetic force, causing the relay 15 to be attracted. When the second switch 13 is turned on, the base B current of the second current control switch 16 is short-circuited to the common ground terminal G, and the collector terminal C and the emitter terminal E of the second current control switch 16 are controlled to be cut off, and the coil of the relay 15 is also powered off, thereby causing the first current control switch 14 to be powered off and cut off.
[0044] In some embodiments, the power source Vcc may be 5 volts, 12 volts, or 24 volts.
[0045] When the relay 15 is in the energized state, the switch of the external output circuit (not shown) is energized, so that the switch of the output circuit (not shown) is turned on; and when the relay 15 is in the non-energized state, the switch of the external output circuit (not shown) is not energized, so that the switch of the output circuit (not shown) is turned off.
[0046] In the above embodiment, the first switch 12 and the second switch 13 are push switches respectively; the first impedance element R1, the second impedance element R2 and the third impedance element R3 are resistors; the first current control switch 14 is a thyristor (Silicon Controlled Rectifier, SCR); the second current control switch 16 is a bipolar junction transistor (BJT); and the unidirectional conductive element 17 is a diode.
[0047] In summary, by setting a thyristor in the latch switch circuit 10 of the present application, through the control characteristics of the thyristor, even if the first switch 12 and the second switch 13 have passed the previous circuit state and the first switch 12 and the second switch 13 are not continuously turned on, the circuit state can still be maintained. In this way, the circuit state can be maintained and it can also be used in a low voltage environment, thereby improving the safety of the operator, and the self-maintaining function can be achieved without the need to design a complex program through a digital logic chip or a microprocessor, which greatly reduces the development cost.
[0048] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.
[0049] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present application and the claims, all of which belong to the scope of protection of the present application.
Claims
1. A latch switch circuit, characterized in that: The latch switch circuit comprises: An input terminal configured to connect to a power source; A first switch connected to the input end; A second switch connected to the input terminal; A first current-controlled switch, comprising a first control end, a first controlled end, and a second controlled end, wherein the first control end is connected to the first switch, and the first controlled end is connected to the input end; a relay connected to the second controlled end; a second current-controlled switch having a second control end, a third controlled end and a fourth controlled end, wherein the second control end is connected to the input end, and the third controlled end is connected to the relay; A common ground terminal is connected to the second switch and the fourth controlled terminal.
2. The latch switch circuit according to claim 1, wherein: When the first switch is turned on, the first control end receives the power supply from the input end through the first switch, the first control end controls the first controlled end and the second controlled end to be conductive with each other, and the relay receives the power supply through the first current control switch, so that the relay generates magnetic force according to the power supply.
3. The latch switch circuit according to claim 2, wherein: When the second switch is turned on, the second control terminal is connected to the common ground terminal through the second switch, the second control terminal controls the third controlled terminal and the fourth controlled terminal to be cut off from each other, and the relay stops providing the magnetic force.
4. The latch switch circuit according to claim 3, characterized in that: The latch switch circuit comprises: The unidirectional conducting element is connected in parallel with the relay.
5. The latch switch circuit according to claim 4, wherein: The first current control switch includes a gate terminal, a first anode terminal and a first cathode terminal; the second current control switch includes a base terminal, a collector terminal and an emitter terminal; and the unidirectional conductive element includes a second anode terminal and a second cathode terminal.
6. The latch switch circuit according to claim 5, characterized in that: The latch switch circuit also includes: a first impedance element, arranged between the input end and the first switch, and between the input end and the second switch; The second impedance element is arranged between the first impedance element and the second switch.
7. The latch switch circuit according to claim 6, wherein: The impedance value of the first impedance element is smaller than the impedance value of the second impedance element.
8. The latch switch circuit according to claim 7, wherein: The latch switch circuit further comprises: The third impedance component is arranged between the gate terminal and the second cathode terminal.
9. The latch switch circuit according to claim 8, wherein: The first pin of the first impedance element is connected to the input terminal, and the first pins of the first switch, the second switch and the second impedance element are respectively connected to the second pin of the first impedance element; the gate terminal is connected to the second pin of the first switch and the first pin of the third impedance element; The first anode terminal is connected to the input terminal and the first pin of the first impedance element; The first pin of the relay is connected to the first cathode terminal, the second cathode terminal and the second pin of the third impedance element; The base terminal is connected to the second pin of the second impedance element, the collector terminal is connected to the second pin of the relay and the second anode terminal, and the emitter terminal is connected to the common ground terminal.