CN219918904U - Touch switch control circuit - Google Patents

Abstract

The utility model belongs to the technical field of switch control, and relates to a touch switch control circuit, which comprises: the capacitor charging circuit is connected with the resistor charging circuit, the triode conducting circuit, the capacitor discharging circuit and the resistor charging circuit through the switch S2; the switch is used for opening and closing the light touch switch control circuit, the resistor charging circuit is used for charging when the switch is closed, the triode conducting circuit is used for conducting a triode when the switch is opened, the capacitor charging circuit is used for charging a capacitor when the triode conducting circuit conducts the triode, and the capacitor discharging circuit is used for discharging the capacitor when the switch is opened. The switch control can be realized by adopting fewer components, the materials are fewer, the cost performance is high, and the switch control is safe and reliable.

Description

Touch switch control circuit

Technical Field

The utility model relates to the technical field of switch control, in particular to a touch switch control circuit.

Background

The tact switch is an electronic switch and belongs to the class of electronic components. In the electric automatic control circuit, a certain operation force is manually applied to the operation direction of the switch to realize the closing and the connection of the circuit, and the circuit is disconnected when the pressure is removed. In short, the switch which can be turned on instantaneously by slightly pressing down is simply provided.

At present, the existing switch is generally controlled by a singlechip, and the economic cost of the whole product is higher due to the addition of the singlechip. However, there is a general need to control the cost of some electronic products, and there is a need for a switch control circuit that is safe and reliable to use and has low cost.

Disclosure of Invention

The utility model aims to solve the technical problems that the existing switch is generally controlled by a singlechip, and the singlechip is added, so that the economic cost of the whole product is higher, and aiming at the defects in the prior art, the utility model provides a light touch switch control circuit which comprises:

the capacitor charging circuit is connected with the resistor charging circuit, the triode conducting circuit, the capacitor discharging circuit and the resistor charging circuit through the switch S2; the switch is used for opening and closing the light touch switch control circuit, the resistor charging circuit is used for charging when the switch is closed, the triode conducting circuit is used for conducting a triode when the switch is opened, the capacitor charging circuit is used for charging a capacitor when the triode conducting circuit conducts the triode, and the capacitor discharging circuit is used for discharging the capacitor when the switch is opened.

Preferably, the switch S2 is a tact switch.

Preferably, the resistance charging circuit includes: resistor R8, resistor R6 and capacitor C4 are connected in series in this order.

Preferably, the triode conduction circuit comprises: one end of the capacitor C4 is connected with one end of the switch S2, and the other end of the switch S2 is respectively connected with one end of the capacitor C3 and the base B of the triode Q4.

Preferably, the capacitor charging circuit includes: the base B of transistor Q3 is connected to the collector of transistor Q4.

Preferably, the capacitive discharge circuit includes: one end of the capacitor C4 is connected with the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected with the collector electrode of the triode Q4.

Preferably, the capacitance C4 has a larger capacitance than the capacitance C3.

Preferably, the transistor Q3 is a PNP transistor.

Preferably, the triode Q4 is an NPN triode.

Preferably, the triode Q3 is any one of 2N3906, BCW70, 3DG120C, S8550, 3CK3F, BC 557.

The light touch switch control circuit has the following beneficial effects: the switch S2, the resistor charging circuit, the triode conducting circuit, the capacitor charging circuit and the capacitor discharging circuit which are electrically connected are adopted; the switch is used for opening and closing the light touch switch control circuit, the resistor charging circuit is used for charging when the switch is closed, the triode conducting circuit is used for conducting a triode when the switch is opened, the capacitor charging circuit is used for charging a capacitor when the triode conducting circuit conducts the triode, and the capacitor discharging circuit is used for discharging the capacitor when the switch is opened; the switch control can be realized by adopting fewer components, the materials are fewer, the cost performance is high, and the switch control is safe and reliable.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art. The utility model will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of a touch switch control circuit according to the present utility model;

FIG. 2 is a circuit diagram of a resistor charging circuit in a tact switch control circuit of the present utility model;

FIG. 3 is a circuit diagram of a triode switch-on circuit in a tact switch control circuit according to the present utility model;

FIG. 4 is a circuit diagram of a capacitor charging circuit in a tact switch control circuit of the present utility model;

fig. 5 is a circuit diagram of a capacitor discharge circuit in a tact switch control circuit of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present utility model, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

Please refer to fig. 1, which is a schematic diagram of a touch switch control circuit according to the present utility model. As shown in fig. 1, in the touch switch control circuit provided in the first embodiment of the present utility model, at least: the capacitor charging circuit 40 and the capacitor discharging circuit 50 are electrically connected through a switch S2, a resistor charging circuit 20, a triode conducting circuit 30, and a capacitor charging circuit 40; the switch S2 is used for turning on and off the light touch switch control circuit, the resistor charging circuit 20 is used for charging when the switch is turned off, the triode conduction circuit 30 is used for conducting the triode when the switch is turned on, the capacitor charging circuit 40 is used for charging the capacitor when the triode conduction circuit conducts the triode, and the capacitor discharging circuit 50 is used for discharging the capacitor when the switch is turned off.

In some alternative implementations, the switch S2 is a tact switch. The touch switch can be understood as a light touch switch which can control the on-off of the switch, namely, the switch is turned on by light pressing, and is turned off by releasing. The tact type switch may include a sealed direct plug-in tact type switch, an LED high insulation resistance type tact type switch, an ultra-long life flat tact type switch, a short stroke patch type tact type switch, a lateral operation type direct plug-in tact type switch, a double-acting key single pole double throw type tact type switch, an equilateral standard type tact type switch, etc. The sealed direct-insert type light touch switch adopts a sealing structure, and the pins are direct-insert type light touch switches, so the sealed direct-insert type light touch switch is sealed. The dustproof and waterproof capabilities are very strong. The LED high insulation resistance type light touch switch is provided with a light emitting diode and the insulation resistance of the light emitting diode is more than 1000MΩ, so the light emitting diode high insulation resistance type light touch switch is provided. The service life of the ultra-long-life flat type light touch switch is as high as 100 ten thousand times, and the actuating mechanism is standard flat type, so that the ultra-long-life flat type light touch switch is provided. The contacts of the high-voltage power supply are made of stainless steel silver plating materials, so that the on-resistance is reduced, and the on-reliability is greatly enhanced. The short-stroke patch type tact switch is characterized in that the stroke of an actuating mechanism is only 0.15+/-0.05mm, and the pins are patch type, so that the short-stroke patch type tact switch is provided. Its short stroke also determines its high service life of 20 tens of thousands of times. The lateral operation type direct-insertion type light touch switch is characterized in that an actuating mechanism is arranged on the side face, and pins are direct-insertion type, so that the lateral operation type direct-insertion type light touch switch is adopted. And two of the four pins play roles of fixing and grounding, and the other two pins are contact on-off terminals. The double-acting key single-pole double-throw type tact switch has double actuating mechanism and contacts are single-pole double-throw, so that it is double-acting key single-pole double-throw type. Its insulation resistance is up to 1000mΩ. The surface shape of the equilateral standard type tact switch is square, and the actuating mechanism is arranged on the standard type of the top surface, so the equilateral standard type tact switch is adopted. There are many kinds of such tact switches, such as: 6.0 x 6.0, 12.0 x 12.0, 6.2 x 6.2, 5.2 x 5.2, 4.9 x 4.9, 7.2 x 7.2, etc., and they are both patch (SMD) and Direct Insert (DIP). The pin of the equilateral standard type touch switch is a patch type touch switch, and the height of the equilateral standard type touch switch is only 0.8mm, so the equilateral standard type touch switch is an ultrathin type patch type touch switch. Its ultra-thin nature determines its suitability for high density mounting.

Referring to fig. 2, a circuit diagram of a resistor charging circuit 20 in a touch switch control circuit according to the present utility model is shown. As shown in fig. 2, the resistance charging circuit 20 includes: resistor R8, resistor R6 and capacitor C4 are connected in series in this order. In the touch switch control circuit, when the switch S2 is powered on in an initial state, the switch S2 is not pressed down and is in an off state, and the capacitor C4 is charged through the resistor R8 and the resistor R6.

Referring to fig. 3, a circuit diagram of a transistor turn-on circuit 30 in a touch switch control circuit according to the present utility model is shown. As shown in fig. 3, the transistor turn-on circuit 30 includes: one end of the capacitor C4 is connected with one end of the switch S2, and the other end of the switch S2 is respectively connected with one end of the capacitor C3 and the base B of the triode Q4. When the switch S2 is pressed, i.e. the switch S2 is in an open state, the capacitor C4 charges the capacitor C3, and the transistor Q4 is turned on.

Referring to fig. 4, a circuit diagram of a capacitor charging circuit 40 in the touch switch control circuit according to the present utility model is shown. As shown in fig. 4, the capacitor charging circuit 40 includes: the base B of transistor Q3 is connected to the collector of transistor Q4. After the triode Q4 is conducted, current passes through an emitter E and a base B of the triode Q3, a resistor R5 and a collector C and an emitter E of the triode Q4, so that the triode Q3 is conducted, voltage is output, and then the capacitor C3 is charged.

Please refer to fig. 5, which is a circuit diagram of a capacitor discharging circuit in the touch switch control circuit of the present utility model. As shown in fig. 5, the capacitive discharge circuit 50 includes: one end of the capacitor C4 is connected with the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected with the collector electrode of the triode Q4. After the switch S2 is released, the capacitor C4 discharges through the diode D2 and the collector C and emitter E of the transistor Q4, and the diode D2 functions to make the capacitor C4 discharge faster.

When the switch S2 key is pressed again, the capacitor C3 charges the capacitor C4 briefly, the voltage of the capacitor C3 is pulled down, the triode Q4 is cut off, and then the triode Q3 is also cut off. Returning to the following steps after releasing the S2 button of the switch: when the initial state is powered up and S2 is not pressed, the capacitor C4 is charged through the resistor R8 and the resistor R6.

The capacitance of capacitor C4 is greater than the capacitance of capacitor C3. The triode Q3 is a PNP triode. The triode Q3 is any one of 2N3906, BCW70, 3DG120C, S8550, 3CK3F, BC557, and other types with the same function may be selected, and in this embodiment, 2N3906 is selected. 2N3906 is mainly used for amplifying electric signals and is widely used in various amplifying circuits.

The triode Q4 is an NPN triode, and in this embodiment, 2N3904 is selected, and other models with the same function can be selected. 2N3904 is a three-terminal NPN BJT, which is made of silicon material and packaged by TO-92. In this type of transistor, most of the charge carriers are electrons, so they are always negatively charged. The state of the transistor can be changed from reverse bias to forward bias to turn on depending on the small voltage (e.g., 0.7V) at the base terminal.

Therefore, the touch switch control circuit can only comprise a PNP triode, an NPN triode, two capacitors C3 and C4 with different capacities, four resistors R5, R6, R7 and R8 and a switch S2, and has fewer adopted components and low cost, thus realizing switch control. The control process of the touch switch control circuit of the utility model is as follows:

firstly, the touch switch control circuit is in an initial state, is electrified, the switch S2 is not pressed down, the capacitor C4 is charged through the resistor R8 and the resistor R6 for a period of time, the voltage is close to the input voltage Vin, the triode Q3 is in a cut-off state, the voltage of the capacitor C3 is close to zero level, and the triode Q4 is in a cut-off state.

Secondly, the switch S2 is pressed down, the capacity of the capacitor C4 is larger than that of the capacitor C3, the terminal voltage of the capacitor C4 cannot be suddenly changed, the capacitor C4 charges the capacitor C3, the triode Q4 is conducted by the larger bias current obtained by the triode Q4, the base potential of the triode Q3 is lowered due to the conduction of the triode Q4, the load is supplied with power by the conduction output voltage of the triode Q3, meanwhile, the capacitor C3 is charged, the triode Q4 obtains bias current from the output end through the resistor R7, and accordingly the triode Q4 is further conducted. After the transistor Q4 is turned on, the capacitor C4 discharges to near zero level through the transistor Q4, and is ready for the next key.

Then when the button of the switch S2 is released, the touch switch control circuit does not act.

When the switch S2 is pressed again, the capacitor C4 is close to zero in voltage, the capacitor C3 charges the capacitor C4 briefly, the instantaneous voltage is close to zero level, the triode Q4 is cut off because no bias current is obtained, the triode Q3 is cut off, no voltage is generated at the output end, and the cut-off tends to be further carried out.

After the switch S2 key is released, the capacitor C4 is charged through the resistor R8 and the resistor R6, and is ready for the next switch S2 key.

Through the design of the embodiment, the utility model has the beneficial effects that: the switch S2, the resistor charging circuit, the triode conducting circuit, the capacitor charging circuit and the capacitor discharging circuit which are electrically connected are adopted; the switch is used for opening and closing the light touch type switch control circuit, the resistor charging circuit is used for charging when the switch is closed, the triode conducting circuit is used for conducting the triode when the switch is opened, the capacitor charging circuit is used for charging the capacitor when the triode conducting circuit conducts the triode, and the capacitor discharging circuit is used for discharging the capacitor when the switch is opened; the switch control can be realized by adopting fewer components, the materials are fewer, the cost performance is high, and the switch control is safe and reliable.

While the utility model has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the utility model. In addition, many modifications may be made to adapt a particular situation to the teachings of the utility model without departing from its scope. Therefore, it is intended that the utility model not be limited to the particular embodiment disclosed, but that the utility model will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. A tact switch control circuit, comprising:

the capacitor charging circuit is connected with the resistor charging circuit, the triode conducting circuit, the capacitor discharging circuit and the resistor charging circuit through the switch S2; the switch is used for opening and closing the light touch switch control circuit, the resistor charging circuit is used for charging when the switch is closed, the triode conducting circuit is used for conducting a triode when the switch is opened, the capacitor charging circuit is used for charging a capacitor when the triode conducting circuit conducts the triode, and the capacitor discharging circuit is used for discharging the capacitor when the switch is opened.

2. The tact switch control circuit of claim 1, wherein the switch S2 is a tact switch.

3. The tact switch control circuit of claim 1, wherein the resistive charging circuit comprises: resistor R8, resistor R6 and capacitor C4 are connected in series in this order.

4. The tact switch control circuit of claim 3, wherein the triode switch-on circuit comprises: one end of the capacitor C4 is connected with one end of the switch S2, and the other end of the switch S2 is respectively connected with one end of the capacitor C3 and the base B of the triode Q4.

5. The tact switch control circuit of claim 4, wherein the capacitive charging circuit comprises: the base B of transistor Q3 is connected to the collector of transistor Q4.

6. The tact switch control circuit of claim 5, wherein the capacitive discharge circuit comprises: one end of the capacitor C4 is connected with the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected with the collector electrode of the triode Q4.

7. A tact switch control circuit according to claim 3, characterized in that the capacitance C4 has a larger capacitance than the capacitance C3.

8. The tact switch control circuit of claim 5, wherein the transistor Q3 is a PNP transistor.

9. The tact switch control circuit of claim 5, wherein the transistor Q4 is an NPN transistor.

10. The tact switch control circuit of claim 8, wherein the transistor Q3 is any one of 2N3906, BCW70, 3DG120C, S8550, 3CK3F, BC 557.