CN102736524A - Power switch - Google Patents

Abstract

A power switch used to control the on-off of electronic equipment and DC power. The power switch includes a switch key, a charging circuit, a control circuit, a trigger and a switch tube. After the charging circuit is connected in parallel with the control circuit, it is electrically connected with the DC power supply through the switch key. The trigger is connected between the control circuit and the switch tube. The switch tube includes a first pole electrically connected to the DC power supply, a second pole electrically connected to the electronic equipment and a control pole electrically connected to the trigger. The control pole controls the on-off of the first and second poles. When the switch key is turned on, the charging circuit charges. After the switch key is disconnected, the voltage charged by the charging circuit makes the control circuit work. If the voltage output from the control circuit to the trigger is greater than the trigger voltage of the trigger, the output signal of the trigger is reversed, and the on-off state of the switch tube Change; if the voltage output from the control circuit to the trigger is lower than the trigger voltage of the trigger, the output signal of the trigger remains unchanged, and the on-off state of the switch tube remains unchanged, so as to prevent misoperation by the user.

Description

switch

technical field

The invention relates to a switch, in particular to a power switch.

Background technique

The current electronic equipment (such as a computer) is generally provided with a power switch connected to an external power supply for connecting or disconnecting the external power supply and the power supply module of the electronic equipment to turn on or off the electronic equipment. However, if the user accidentally touches the power switch during operation, the electronic device will be turned on or off immediately, which brings great trouble to the user. For example, if the user does not want to start the electronic device, As a result, if the power switch is accidentally touched, the electronic device will be turned on, which will waste electric energy; if the electronic device is not intended to be turned off, but the power switch is accidentally touched, the electronic device will be turned off , causing some files to be lost without being saved.

Contents of the invention

In view of this, it is necessary to provide a power switch that prevents misoperation by users.

A power switch used to control the on-off of electronic equipment and DC power. The power switch includes a switch key, a charging circuit, a control circuit, a trigger and a switch tube. The charging circuit is electrically connected to the DC power supply through the switch key. The control circuit is connected in parallel with the charging circuit. The trigger is connected between the control circuit and the switch tube. The switch tube includes a first pole, a second pole and a control pole. The first pole is electrically connected to a DC power supply. The second pole is electrically connected with the electronic device. The control pole is electrically connected to the trigger, and is used to control the on-off of the first pole and the second pole. When the switch key is turned on, the charging circuit performs charging. After the switch key is disconnected, the voltage charged by the charging circuit makes the control circuit work. If the voltage output by the control circuit to the trigger is greater than the trigger voltage of the trigger, the trigger The output signal of the flip-flop is reversed, so that the on-off state of the switch tube is changed; if the voltage output by the control circuit to the flip-flop is less than the trigger voltage of the flip-flop, the output signal of the flip-flop remains unchanged , to keep the on-off state of the switch tube unchanged.

In the power switch of the present invention, after the power switch is turned on and then turned off, if the voltage output by the control circuit to the trigger is less than the trigger voltage of the trigger, the output signal of the trigger remains The on-off state of the switch tube remains unchanged, so that the user's misoperation can be effectively prevented.

Description of drawings

Fig. 1 is a functional block diagram of a power switch in a preferred embodiment of the present invention.

FIG. 2 is a circuit diagram of the power switch of FIG. 1 .

Description of main component symbols

switch 100 Electronic equipment 200 processor 210 timer 220 power button K first end K1 second end K2 ontology K3 charging circuit 20 charging capacitor C0 Charging resistor R0 Control circuit 30 diode D. first triode T1 second triode T2 third triode T3 The fourth triode T4 fifth triode T5 first resistor R1 Second resistor R2 third resistor R3 Fourth resistor R4 fifth resistor R5 Sixth resistor R6 Seventh resistor R7 Eighth resistor R8 Ninth resistance R9 Tenth resistor R10 turning tube 50 first pole 51 second pole 52 control pole 53 trigger 70 power pin VDD clock pin CP1 reset pin CD1 output pin Q Eleventh resistor R11 reset circuit 80 Sixth triode T6 Twelfth resistor R12 Thirteenth resistance R13 Fourteenth resistance R14 Fifteenth resistor R15 DC power supply Vcc

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

Detailed ways

1 and 2 are a power switch 100 provided by an embodiment of the present invention, which is used to control the electrical connection or disconnection of an electronic device 200 with a DC power supply Vcc. The electronic device 200 includes a processor 210 and a timer 220 electrically connected to each other. The power switch 100 includes a switch key K, a charging circuit 20 , a control circuit 30 , a switch tube 50 , a trigger 70 and a reset circuit 80 . The charging circuit 20 is electrically connected to the DC power supply Vcc through the switch key K. The control circuit 30 is electrically connected to the charging circuit 20 . The trigger 70 is connected between the control circuit 30 and the switch tube 50 .

The switch key K includes a first end K1, a second end K2 and a body K3. The body K3 is used to electrically connect the first end K1 to the second end K2. The first end K1 is electrically connected to the charging circuit 20 , and the second end K2 is electrically connected to the DC power supply Vcc.

The charging circuit 20 includes a diode D, a first resistor R1, a charging capacitor C0 and a charging resistor R0. One end of the charging capacitor C0 is electrically connected to the DC power supply Vcc through the first resistor R1, the diode D and the switch key K in sequence, and the other end is grounded. Wherein, the anode of the diode D is electrically connected to the switch key K, and the cathode of the diode D is electrically connected to the first resistor R1. The charging resistor R0 is connected in parallel with the charging capacitor C0. When the switch key K is closed, the charging capacitor C0 is electrically connected to the DC power supply Vcc for charging. In this embodiment, the capacitance value of the charging capacitor C0 is 106KF, and the resistance value of the charging resistor R0 is 1MΩ.

The control circuit 30 includes a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and A capacitor C1 to ground.

In this embodiment, the first triode T1, the second triode T2, the third triode T3, the fourth triode T4, and the fifth triode T5 are all NPN type triodes. When no bias voltage is applied, the NPN transistor is cut off; when a relatively large bias voltage is applied to the base, so that the voltage difference between the base and the emitter is above 0.7 V, the The NPN transistor is turned on.

The base of the first triode T1 is grounded through the second resistor R2 and the charging resistor R0 sequentially. The collector of the first triode T1 is electrically connected to the DC power supply Vcc, and the emitter of the first triode T1 is electrically connected to the collector of the third triode T3.

The base of the second transistor T2 is electrically connected to the first terminal K1 of the switch key K through the third resistor R3. The collector of the second transistor T2 is electrically connected to the DC power supply Vcc through the fourth resistor R4, and the emitter of the second transistor T2 is grounded.

The base of the third transistor T3 is electrically connected to the collector of the second transistor T2, and the emitter of the third transistor T3 is electrically connected to the base of the fourth transistor T4. connect. The emitter of the third transistor T3 is also grounded through the fifth resistor R5. The ground capacitor C1 is connected in parallel with the fifth resistor R5.

The collector of the fourth transistor T4 is electrically connected to the DC power supply Vcc through the sixth resistor R6, and is electrically connected to the base of the fifth transistor T5 through the seventh resistor R7. The emitter of the fourth transistor T4 is grounded through the eighth resistor R8.

The base of the fifth transistor T5 is also grounded through the ninth resistor R9. The collector of the fifth transistor T5 is electrically connected to the DC power supply Vcc through the tenth resistor R10, and the emitter of the fifth transistor T5 is connected to the emitter of the fourth transistor T4. electrical connection.

In this embodiment, the resistance of the first resistor R1 is 220KΩ, the resistance of the second resistor R2 is 220KΩ, the resistance of the third resistor R3 is 220KΩ, and the resistance of the fourth resistor R4 value is 47KΩ, the resistance value of the fifth resistor is 1KΩ, the resistance value of the sixth resistor R6 is 124KΩ, the resistance value of the seventh resistor R7 is 750KΩ, and the resistance value of the eighth resistor R8 is 22KΩ , the resistance value of the ninth resistor R9 is 374KΩ, the resistance value of the tenth resistor R10 is 220KΩ, and the capacitance value of the grounding capacitor C1 is 103KF.

The switch tube 50 includes a first pole 51 , a second pole 52 and a control pole 53 . The first pole 51 is electrically connected to the DC power supply Vcc, and the second pole 52 is electrically connected to the electronic device 200 . The control pole 53 is electrically connected to the trigger 70 for controlling the on-off of the first pole 51 and the second pole 52 . In this embodiment, the switch transistor is a P-channel field effect transistor, wherein the first pole 51 is a drain, the second pole 52 is a source, and the control pole 53 is a gate. The P-channel switch has a low-level turn-on characteristic. When the control pole 53 is at a low level "0", the P-channel switch is turned on, so that the first pole 51 and the first pole 51 are connected to each other. The second pole 52 is connected; when the control pole 53 is at a high level “1”, the P-channel switch is turned off, so that the first pole 51 is disconnected from the second pole 52 .

。所述电源引脚VDD与所述直流电源Vcc电连接。所述时钟引脚CP1与所述第五三极管T5的集电极电连接。所述复位引脚CD1与所述复位电路80电连接。所述反向输出引脚

通过所述第十一电阻R11与所述开关管50的控制极53电连接。所述第十一电阻R11主要起到分压的作用，使得所述开关管50的控制极53的电压降低，保护所述开关管50不会因电压太高而损坏。所述反向输出引脚

的电平始终与所述输出引脚Q的电平相反，并随着所述输出引脚Q的电平的变化而变化。在本实施方式中，所述触发器70的触发电压为4V，也就是说当所述控制电路30给所述时钟引脚CP1输入一个大于4V的电压时，所述触发器70发出一个触发信号，使所述输出引脚Q的电平反向，使所述开关管50的通断状态改变。当所述控制电路30给所述时钟引脚CP1输入一个小于4V的电压时，所述触发器70不会发出一个触发信号，所述输出引脚Q的电平维持不变，使所述开关管50的通断状态维持不变。在本实施方式中，所述触发器70的型号为4013D。 The flip-flop 70 is used to control the switch tube 50 to be turned on or off according to the signal of the control circuit 30 . The flip-flop 70 includes a power supply pin VDD, a clock pin CP1, a reset pin CD1, an output pin Q and an inverted output pin

. The power supply pin VDD is electrically connected to the DC power supply Vcc. The clock pin CP1 is electrically connected to the collector of the fifth transistor T5. The reset pin CD1 is electrically connected to the reset circuit 80 . The inverting output pin

It is electrically connected to the control electrode 53 of the switch tube 50 through the eleventh resistor R11. The eleventh resistor R11 mainly functions as a voltage divider to reduce the voltage of the control electrode 53 of the switch tube 50 and protect the switch tube 50 from being damaged due to too high voltage. The inverting output pin

The level of is always opposite to the level of the output pin Q, and changes as the level of the output pin Q changes. In this embodiment, the trigger voltage of the flip-flop 70 is 4V, that is to say, when the control circuit 30 inputs a voltage greater than 4V to the clock pin CP1, the flip-flop 70 sends a trigger signal , inverting the level of the output pin Q to change the on-off state of the switch tube 50 . When the control circuit 30 inputs a voltage less than 4V to the clock pin CP1, the flip-flop 70 will not send a trigger signal, and the level of the output pin Q remains unchanged, so that the switch The on-off state of the tube 50 remains unchanged. In this embodiment, the model of the trigger 70 is 4013D.

The reset circuit 80 is used to initialize the flip-flop 70 so that when the flip-flop 70 is in an initial state, the first pole 51 of the switch tube 50 is disconnected from the second pole 52 . The reset circuit 80 includes a sixth transistor T6, a twelfth resistor R12 and a thirteenth resistor R13. The base of the sixth transistor T6 is electrically connected to the DC power supply Vcc through the twelfth resistor R12. The collector of the sixth transistor T6 is not only electrically connected to the DC power supply Vcc through the thirteenth resistor R13 , but also electrically connected to the reset pin CD1 of the flip-flop 70 . The emitter of the sixth transistor T6 is grounded. In this embodiment, the resistance value of the twelfth resistor R12 is 39KΩ, and the resistance value of the thirteenth resistor R13 is 47KΩ. It can be understood that the DC power supply Vcc is provided by the power converter of the electronic device 200, and the power converter is electrically connected to an external power supply. When the power converter of the electronic device 200 is connected to the external AC power supply After being turned on, the reset circuit 80 immediately sends a reset signal to the flip-flop 70 .

The control circuit 30 further includes a fourteenth resistor R14 and a fifteenth resistor R15. The first end K1 of the switch key K is also grounded through the fourteenth resistor R14 and the fifteenth resistor R15 . The input end of the timer 220 of the electronic device 200 is connected between the fourteenth resistor R14 and the fifteenth resistor R15 , and the output end is electrically connected to the processor 210 . The fourteenth resistor R14 and the fifteenth resistor R15 mainly function as a voltage divider, reducing the voltage at the input terminal of the timer 220 to a voltage (such as 3.3V) that the timer 220 can withstand. Since when the switch key K is turned on, the DC power supply Vcc is electrically connected to the timer 220 through the fourteenth resistor R14, and there will be current entering the timer 220 at this time, so the timer 220 can Calculate the time when the switch key K is turned on. The timer 220 internally stores a predetermined time value. The timer 220 can also compare the measured time with the predetermined time value, and transmit the comparison result to the processor 210, and the processor 210 executes corresponding functions according to the comparison result. For example, when the detected time is less than the predetermined time, the processor 210 executes other functions (such as locking the keypad), that is to say, the switch key K can be used as a function key at this time. When the detected time is greater than the predetermined time, the processor 210 executes a shutdown action. The predetermined time refers to the time required for the charging circuit 20 to be charged until the first transistor T1 is turned on when the switch key K is closed. In this embodiment, the resistance value of the fourteenth resistor R14 is 220KΩ, and the resistance value of the fifteenth resistor R15 is 74KΩ.

变成高电平“1”，使得所述开关管50的第一极51与第二极52断开，所述处理器210与所述直流电源Vcc断开。当所述控制电路30传递给所述时钟引脚CP1的电压大于所述触发器70的触发电压时，所述触发器70会产生一脉冲信号，使得所述输出引脚Q的电平反向，变成高电平“1”，所述反向输出引脚

的电平也随之反向，变成低电平“0”，使得所述开关管50的第一极51与第二极52导通。当所述时钟引脚CP1的电压小于所述触发器70内存储的门限电压时，所述触发器70不会产生一脉冲信号，所述输出引脚Q及所述反向输出引脚

的电平保持不变，也即所述反向输出引脚

仍然为高电平“1”，使得所述开关管50不导通。所述电源开关100包括以下四种工作状态： The working process of the power switch 100 is as follows: since the sixth transistor T6 is electrically connected to the DC power supply Vcc through the thirteenth resistor R13, the sixth transistor T6 is turned on, so that The reset terminal CD1 of the flip-flop 70 is grounded, the flip-flop 70 is reset, the output pin Q becomes low level "0", and the inverted output pin

becomes high level "1", so that the first pole 51 and the second pole 52 of the switching tube 50 are disconnected, and the processor 210 is disconnected from the DC power supply Vcc. When the voltage delivered by the control circuit 30 to the clock pin CP1 is greater than the trigger voltage of the flip-flop 70, the flip-flop 70 will generate a pulse signal, so that the level of the output pin Q is reversed, goes high to a “1”, the inverting output pin

The level of the switch tube 50 is also reversed and becomes a low level "0", so that the first pole 51 and the second pole 52 of the switch tube 50 are turned on. When the voltage of the clock pin CP1 is less than the threshold voltage stored in the flip-flop 70, the flip-flop 70 will not generate a pulse signal, the output pin Q and the inverted output pin

The level remains unchanged, that is, the inverted output pin

Still at high level "1", so that the switch tube 50 is not turned on. The power switch 100 includes the following four working states:

(1) When the switch key K is short-pressed and the hand is released, the charge in the charging circuit 20 is not enough to turn on the first triode T1, and then the first triode T1 is turned off. When the base voltage of the second transistor T2 is zero, the second transistor T2 is turned off. At this time, the base of the third transistor T3 is electrically connected to the DC power supply Vcc through the fourth resistor R4, and the emitter is grounded, so that the third transistor T3 is turned on; The base of the transistor T4 is grounded through the fifth resistor R5, and the fourth transistor T4 is turned off; the base of the fifth transistor T5 passes through the sixth resistor R6 and the seventh resistor R7 is electrically connected to the DC power supply Vcc, and the emitter is grounded, then the fifth triode T5 is turned on, and the voltage of the clock pin CP1 of the flip-flop 70 is Vcc*R8/[(R6+R7 )//R10+R8//R9], it is calculated that the voltage of the clock pin CP1 at this time is approximately equal to 0.76V, which is less than the trigger voltage of the flip-flop 70, so the flip-flop 70 does not act, making The switch tube 50 is not turned on, and the processor 210 is disconnected from the DC power supply Vcc.

(2) When the switch key K is long pressed and then released, so that the voltage charged by the charging circuit 20 can turn on the first triode T1; the base of the second triode T2 is connected to the When the DC power supply Vcc is disconnected, the second transistor T2 is turned off; the base of the third transistor T3 is electrically connected to the DC power supply Vcc through the fourth resistor R4, and the emitter is grounded. Then the third transistor T3 is turned on; the base of the fourth transistor T4 is electrically connected to the DC power supply Vcc through the first transistor T1 and the third transistor T3, If the emitter is grounded, the fourth triode T4 is turned on; at this time, the voltage of the fifth triode T5 is Vcc*R9/[R6+R8//(R7+R9)], which cannot reach When the turn-on voltage of the fifth triode T5 is reached, the fifth triode T5 is turned off, and at this time, the clock pin CP1 is electrically connected to the DC power supply Vcc through the tenth resistor R10, so that the Only when the voltage of the clock pin CP1 exceeds the threshold voltage stored in the flip-flop 70, the flip-flop 70 will generate a pulse signal, so that the level of the output pin Q is reversed, from low level to high level, the inverted output pin becomes low level, the switch tube 50 is turned on, the processor 210 is electrically connected to the DC power supply Vcc, and the electronic device 200 is turned on.

的电平反向，则所述开关管50的状态不变。 (3) When the electronic device 200 is in operation and the user short presses the switch key K, the whole process is similar to state (1), and the trigger 70 does not act, so the reverse output pin

If the level of the switching tube 50 is reversed, the state of the switching tube 50 remains unchanged.

(4) When the electronic device 200 is working, and the user presses the switch key K for a long time, the whole process is similar to state (2), and the trigger 70 sends a pulse signal, so that the reverse output leads foot If the level of the switching tube 50 is reversed, the state of the switching tube 50 changes, the switching tube is turned off, the electronic device 200 is disconnected from the DC power supply Vcc, and the electronic device 200 is turned off.

In the power switch of the present invention, after the power switch is turned on and then turned off, if the voltage output by the control circuit to the trigger is less than the trigger voltage of the trigger, the output signal of the trigger remains unchanged, the on-off state of the switch tube remains unchanged, thus effectively preventing the user from misoperation.

It can be understood that those skilled in the art can make various other corresponding changes and modifications according to the technical concept of the present invention, and all these changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (10)

1. A power switch, used to control the on-off of electronic equipment and a DC power supply, the power switch includes a switch key, a control circuit, a trigger and a switch tube; the control circuit is electrically connected with the switch key and the trigger ; The switch tube includes a first pole, a second pole and a control pole, the first pole is electrically connected to a DC power supply, the second pole is electrically connected to the electronic device, and the control pole is connected to the trigger Electrically connected, used to control the on-off of the first pole and the second pole; the charging circuit is electrically connected to the DC power supply through the switch key; the control circuit is connected in parallel with the charging circuit; The trigger is connected between the control circuit and the switch tube; the switch tube includes a first pole, a second pole and a control pole; the first pole is electrically connected to a DC power supply; the second pole It is electrically connected with the electronic equipment; the control pole is electrically connected with the trigger, and is used to control the on-off of the first pole and the second pole; when the switch key is turned on, the charging circuit Charging; after the switch key is disconnected, the charging voltage of the charging circuit makes the control circuit work, if the voltage output by the control circuit to the trigger is greater than the trigger voltage of the trigger, the The output signal of the flip-flop is reversed to change the on-off state of the switch; if the voltage output by the control circuit to the flip-flop is less than the trigger voltage of the flip-flop, the output signal of the flip-flop remain unchanged, so that the on-off state of the switch tube remains unchanged. 2. The power switch according to claim 1, wherein the switch key comprises a body, a first end and a second end; the body is used to electrically connect the first end to the second end ; The first end is electrically connected to the control circuit, and the second end is electrically connected to the DC power supply. 3. The power switch according to claim 2, wherein the charging circuit comprises a charging capacitor and a charging resistor, one end of the charging capacitor is electrically connected to the DC power supply through the switch key, and the other end is Grounded; the charging resistor is connected in parallel with the charging capacitor. 4. The power switch according to claim 3, wherein the control circuit comprises a first triode, a second triode, a third triode, a fourth triode, and a fifth triode ; the base of the first triode is grounded sequentially through the second resistor and the charging resistor; the collector of the first triode is electrically connected to the DC power supply, and the first triode The emitter of the transistor is electrically connected to the collector of the third transistor; the base of the second transistor is electrically connected to the first end of the switch key through the third resistor; The collector of the transistor is electrically connected to the DC power supply through the fourth resistor, the emitter of the second triode is grounded; the base of the third triode is connected to the second triode The collector is electrically connected, the emitter of the third triode is electrically connected with the base of the fourth triode; the emitter of the third triode is grounded; the collector of the fourth triode The electrode is electrically connected to the DC power supply, and is electrically connected to the base of the fifth triode; the emitter of the fourth triode is grounded; the base of the fifth triode is grounded; the The collector of the fifth triode is electrically connected to the DC power supply, and the emitter of the fifth triode is electrically connected to the emitter of the fourth triode. 5. The power switch according to claim 4, wherein the charging circuit further comprises a first resistor and a diode; the anode of the diode is electrically connected to the DC power supply, and the first resistor is connected to the between the cathode of the diode and the charging capacitor; the control circuit also includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a Ten resistors and grounding capacitors, the second resistor is between the cathode of the diode and the base of the first triode, the third resistor is connected between the first end of the switch and the second Between the bases of the triodes, the fourth resistor is connected between the DC power supply and the bases of the second triodes, and the fifth resistor is connected to the emitter of the third triodes Between the pole and the ground, the grounding capacitor is connected in parallel with the fifth resistor, the sixth resistor is connected between the DC power supply and the collector of the fourth triode, and the seventh resistor is connected to Between the collector of the fourth triode and the base of the fifth triode, the eighth resistor is connected between the emitter of the fifth triode and the ground, and the ninth The resistor is connected between the base of the fifth triode and the ground, and the tenth resistor is connected between the collector of the fifth triode and the ground. 6. power switch as claimed in claim 4, is characterized in that, described flip-flop comprises clock pin, output pin, reverse output pin and reset pin; Described clock pin and described fifth three The collector of the pole tube is electrically connected, the level of the reverse output pin is always opposite to the level of the output pin, and changes with the change of the level of the output pin, the reverse The output pin is electrically connected to the control electrode of the switch tube through an eleventh resistor, and the power switch further includes a reset circuit, and the reset circuit is electrically connected to the reset pin. 7. The power switch according to claim 6, wherein the reset circuit comprises a power supply and a sixth triode, the base of the sixth triode is electrically connected to the DC power supply, and the set The electrode is electrically connected to the reset pin of the flip-flop, and the emitter is grounded. 8. The power switch according to claim 7, wherein the reset circuit further comprises a twelfth resistor and a thirteenth resistor; both ends of the twelfth resistor are respectively connected to the sixth three pole The base of the transistor is electrically connected to the DC power supply, and the two ends of the thirteenth resistor are respectively electrically connected to the collector of the sixth triode and the DC power supply. 9. The power switch according to claim 1, wherein the electronic device includes a timer and a processor electrically connected to each other, the switch key is also electrically connected to the timer, and the timer is used to detect Measure the time when the switch key is turned on, compare the obtained time with the predetermined time value stored inside the timer, and transmit the comparison result to the processor, and the processor, according to the comparison result, Execute the corresponding function. 10. The power switch according to claim 9, wherein the first end of the switch key is grounded through a fourteenth resistor and a fifteenth resistor, and the input end of the timer is connected to the first Between the fourteenth resistor and the fifteenth resistor, the output end of the timer is electrically connected to the processor.

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