CN216252683U

CN216252683U - Electronic switch

Info

Publication number: CN216252683U
Application number: CN202121496780.5U
Authority: CN
Inventors: 李明; 沈丽萍; 方华磊; 孙盼; 申明宇
Original assignee: Hangzhou Santan Medical Technology Co Ltd
Current assignee: Hangzhou Santan Medical Technology Co Ltd
Priority date: 2021-07-02
Filing date: 2021-07-02
Publication date: 2022-04-08
Anticipated expiration: 2031-07-02

Abstract

The utility model relates to an electronic switch which comprises an electronic switch circuit (A), a starting circuit (B), a light touch key (K1), a key detection circuit (C), a power supply holding circuit (D) and a single chip microcomputer (U1), wherein the light touch key (K1) comprises a first pin (1) and a second pin (2), the electronic switch circuit (A) is connected to the first pin (1), the starting circuit (B) is connected to the second pin (2), the key detection circuit (C) is respectively connected with the second pin (2) and the single chip microcomputer (U1), and the power supply holding circuit (D) is respectively connected with the electronic switch circuit (A) and the single chip microcomputer (U1). The electronic switch of the utility model combines the power switch and the function key into a whole, and can solve the problem of power consumption still existing in the shutdown state in the prior art.

Description

Electronic switch

Technical Field

The utility model relates to the technical field of electronics, in particular to a brain switch.

Background

In a low-voltage direct-current circuit, a power switch is used for controlling an input power supply of the circuit, a functional key is used for selecting or adjusting the circuit, the two keys respectively play their roles, but in some simple application occasions, such as products with extremely small volume and product application related to appearance limitation, only one key is provided, and the key is generally required to have the function of combining the power switch and the functional key into a whole.

At present, a key in the prior art has a practical mechanical switch as a power switch, all current of a circuit in the design is equalized to a contact of the mechanical switch, the contact can be burnt by electric arc generated in the switching process, and the repeated switching has great influence on the service life of the mechanical switch.

In the prior art, a self-locking circuit consisting of a light touch switch and a triode circuit is used, which can only realize the switching of a power supply and does not have the function of combining a power supply switch and a functional key into a whole.

In the prior art, a circuit design combining a power switch and a function key into a whole is adopted, and a singlechip is used for detecting the level change of the key to control the power switch, the power switch and the function switch. In the design, even when the computer is turned off, the singlechip circuit of the circuit board needs to be powered all the time, and the state of the key can be identified only when the singlechip works all the time, so that the computer always consumes power in the design and is not suitable for occasions with harsh standby functions or battery power supply occasions.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an electronic switch, which solves the problem of power consumption when a power switch and a function key are combined into a whole in the prior art.

In order to achieve the above object, the present invention provides an electronic switch, which includes an electronic switch circuit, a start circuit, a touch button, a button detection circuit, a power holding circuit and a single chip microcomputer, wherein the touch button includes a first pin and a second pin, the electronic switch circuit is connected to the first pin, the start circuit is connected to the second pin, the button detection circuit is respectively connected to the second pin and the single chip microcomputer, and the power holding circuit is respectively connected to the electronic switch circuit and the single chip microcomputer.

According to one aspect of the utility model, the electronic switching circuit comprises a PNP transistor, a second resistor, an NPN transistor, and a fourth resistor;

the emitter of the PNP triode is connected to the input end of a power supply, the collector of the PNP triode is connected to the output end of the power supply, and the base of the PNP triode is connected to the collector of the NPN triode through the second resistor;

and an emitter of the NPN triode is grounded, and a base of the NPN triode is grounded through a fourth resistor and is simultaneously connected to the first pin of the light touch key.

According to one aspect of the utility model, the start-up circuit comprises a first resistor and a first diode, wherein one end of the first resistor is connected to the power input end, the other end of the first resistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the second pin of the light touch key.

According to one aspect of the utility model, the key detection circuit comprises a pull-up resistor, a supply voltage and a second diode, wherein one end of the pull-up resistor is connected to the supply voltage, and the other end of the pull-up resistor is connected to an anode of the second diode and a first I/O port of a single chip microcomputer at the same time, and is used for controlling the on and off of the NPN triode.

According to one aspect of the utility model, the power supply holding circuit comprises a third resistor, one end of the third resistor is connected to a base electrode of the NPN triode, and the other end of the third resistor is connected to the second I/O port of the single chip microcomputer, and the third resistor is used for controlling the conduction and the cut-off of the NPN triode.

The electronic switch of the utility model combines the power switch and the function keys into a whole, can control the holding circuit of the power supply to continue to be effective through the single chip microcomputer software, can set the effective pressing time of the keys, prevents interference or mistaken touch, and forms logical self-locking. The prior art uses hardware self-locking, and the effective time of the key cannot be set. Meanwhile, after the electronic switch is turned off, the power supply is completely cut off, and the standby power consumption is zero.

Drawings

Fig. 1 schematically shows a control circuit diagram of an electronic switch according to the utility model.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the utility model, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

The present invention is described in detail below with reference to the drawings and the specific embodiments, which are not repeated herein, but the embodiments of the present invention are not limited to the following embodiments.

As shown in fig. 1, the present invention provides an electronic switch, which includes an electronic switch circuit a, a start circuit B, a touch key K1, a key detection circuit C, a power holding circuit D, and a single chip microcomputer U1, where the touch key K1 includes a first pin 1 and a second pin 2, the electronic switch circuit a is connected to the first pin 1, the start circuit B is connected to the second pin 2, the key detection circuit C is respectively connected to the second pin 2 and the single chip microcomputer U1, and the power holding circuit D is respectively connected to the electronic switch circuit a and the single chip microcomputer U1.

Specifically, in the present invention, as shown in fig. 1, the electronic switch circuit a includes a PNP transistor Q1, a second resistor R2, an NPN transistor Q2, and a fourth resistor R4. The emitter of the PNP transistor Q1 is connected to the input terminal of the power supply, the collector is connected to the output terminal of the power supply, and the base is connected to the collector of the NPN transistor Q2 through the second resistor R2. The emitter of the NPN transistor Q2 is grounded, and the base is grounded through a fourth resistor R4 and connected to the first pin 1 of the light touch key K1.

The starting circuit B of the utility model comprises a first resistor R1 and a first diode D1, wherein one end of the first resistor R1 is connected to the power supply input end, the other end is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the second pin 2 of the light touch key K1.

The key detection circuit C comprises a pull-up resistor R5, a power supply voltage VCC and a second diode D2, wherein one end of the pull-up resistor R5 is connected to the power supply voltage VCC, and the other end of the pull-up resistor R3526 is connected to the anode of the second diode D2 and the first I/O port of the singlechip U1 and used for controlling the connection and disconnection of an NPN triode Q2.

The power supply holding circuit D comprises a third resistor R3, wherein one end of the third resistor R3 is connected to the base electrode of an NPN triode Q2, and the other end of the third resistor R3 is connected to a second I/O port of a single chip microcomputer U1 and used for controlling the conduction and the cut-off of the NPN triode Q2.

The electronic switch of the utility model has the following working procedures:

standby: the NPN triode Q2 is kept off under the action of the fourth resistor, the second resistor R2 has no current, the PNP triode Q1 is in an off state, the power supply does not output, and the power consumption of the circuit is zero.

Starting up: when the light touch key K1 is pressed, current flows through a first resistor R1 and a first diode D1 of the starting circuit, flows to the base of an NPN triode Q2 through the light touch key K1, the NPN triode Q2 is changed into a conducting state from an off state, a base current is provided for the PNP triode Q1 through a second resistor, the NPN triode Q2 is changed into the conducting state from the off state, the power supply is temporarily turned on, and the rear circuit starts to work. After the single chip microcomputer U1 is started, the second I/O port (I/O1 shown in figure 1) is output to high level by the time Ton set in a delayed mode, the base current of the NPN triode Q2 is maintained through the third resistor R3, the light touch key K1 is released, the electronic switch circuit is still kept in an open state, and the power supply is always kept on.

The operation state is as follows: pressing the touch key K1 will not affect the state of the power holding circuit, but the second resistor and the pull-up resistor R5 will change the first I/O port (I/O2 shown in fig. 1) of the single chip from high level to low level, and its voltage is as follows:

VL＝VD2+VQbe

VD2 is the tube voltage drop of the second diode D2, the silicon tube is about 0.6V, and the germanium tube is about 0.2V.

VQbe is the be voltage drop of NPN transistor Q2, which is about 0.4V at low current.

In summary, VL is about 0.6V-1.0V, and this voltage is recognized as low level by the singlechip, which can recognize this key as a function key.

Shutdown: when shutdown is needed, the light touch key K1 is pressed, the first I/O port (I/O2 shown in figure 1) of the single chip microcomputer recognizes that the level changes, the second I/O port (I/O1 shown in figure 1) is output to be low level, the base electrode of the NPN triode Q2 loses current input, the conduction is changed into cutoff, and the PNP triode Q1 is changed into cutoff accordingly. The electronic switch closes the power output, the whole circuit is completely powered off, and the power consumption is zero.

The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and it is apparent to those skilled in the art that various modifications and variations can be made in the present invention. For example, the PNP transistor Q1 in the circuit can be replaced by a P-channel fet or a relay, or the NPN transistor Q2 can be replaced by an N-channel fet, which are consistent with the concept of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The electronic switch is characterized by comprising an electronic switch circuit (A), a starting circuit (B), a light touch key (K1), a key detection circuit (C), a power supply holding circuit (D) and a single chip microcomputer (U1), wherein the light touch key (K1) comprises a first pin (1) and a second pin (2), the electronic switch circuit (A) is connected onto the first pin (1), the starting circuit (B) is connected onto the second pin (2), the key detection circuit (C) is respectively connected with the second pin (2) and the single chip microcomputer (U1), and the power supply holding circuit (D) is respectively connected with the electronic switch circuit (A) and the single chip microcomputer (U1).

2. The electronic switch of claim 1, wherein the electronic switch circuit (a) comprises a PNP transistor (Q1), a second resistor (R2), an NPN transistor (Q2), and a fourth resistor (R4);

the emitter of the PNP triode (Q1) is connected to the input end of the power supply, the collector of the PNP triode is connected to the output end of the power supply, and the base of the PNP triode is connected to the collector of the NPN triode (Q2) through the second resistor (R2);

the emitter of the NPN triode (Q2) is grounded, and the base of the NPN triode is grounded through a fourth resistor (R4) and is also connected to the first pin (1) of the light touch key (K1).

3. An electronic switch according to claim 2, characterised in that the start-up circuit (B) comprises a first resistor (R1) and a first diode (D1), the first resistor (R1) being connected at one end to the power supply input and at the other end to the anode of the first diode (D1), the cathode of the first diode (D1) being connected to the second pin (2) of the touch key (K1).

4. The electronic switch according to claim 3, wherein the key detection circuit (C) comprises a pull-up resistor (R5), a supply Voltage (VCC) and a second diode (D2), wherein one end of the pull-up resistor (R5) is connected to the supply Voltage (VCC), and the other end of the pull-up resistor is connected to the anode of the second diode (D2) and the first I/O port of the single chip microcomputer (U1) at the same time, and is used for controlling the on and off of the NPN transistor (Q2).

5. The electronic switch according to claim 4, characterized in that the power holding circuit (D) comprises a third resistor (R3), one end of the third resistor (R3) is connected to the base of an NPN transistor (Q2), and the other end is connected to the second I/O port of the single-chip microcomputer (U1) for controlling the on and off of the NPN transistor (Q2).