TW201530302A - Circuit of on/off switch test - Google Patents

Abstract

A circuit of on/off switch test is utilized to test on /off switch of a main board. The circuit of on/off switch test includes first to fifth electronic switches, first to sixth resistors, first and second capacitor, and first and second diodes. Connected or not of the first and second electronic switches manage power on of the main board. Connected or not of the third to fifth electronic switches manage power off of the main board.

Description

Switching machine test circuit

The invention relates to a switch test circuit.

The conventional computer DC switch test usually requires the test engineer to manually press the power button of the computer to power on and off to verify the quality and reliability of the computer, which requires a lot of manpower.

In view of the above, it is necessary to provide a switch test circuit to automatically test the on/off of the computer's motherboard.

A switch test circuit for testing a switchboard of a motherboard, the motherboard is also connected to a power supply, the power supply is used to supply power to the motherboard, and the test circuit of the switch is connected to the motherboard Between the boot signal output pin of the button and the output pin of the video graphics array connector on the motherboard, the boot signal output pin of the power button is connected to the control pin of the power supply, and the switch test circuit includes First to fifth electronic switches, first to sixth resistors, first and second capacitors, and first and second diodes, the first output pin of the power supply is transmitted through the first resistor and the first The control end of the electronic switch is connected to the control terminal of the first electronic switch, and the first end of the first electronic switch is connected to the second output pin of the power supply through the second resistor. The first end of the first electronic switch is connected to the control end of the second electronic switch, and the first end of the second electronic switch is connected to the boot of the power button An output pin, the second end of the second electronic switch is grounded, and a first output pin of the video graphics array connector on the motherboard is connected to an anode of the first diode, a cathode of the first diode Connecting the third electronic switch to the control end of the third electronic switch, the first end of the third electronic switch is connected to the first output pin of the power supply through the fourth resistor, and the second end of the third electronic switch Grounding, the first end of the third electronic switch is further connected to the control end of the fourth electronic switch through the second capacitor, and the control end of the fourth electronic switch is further connected to the first output of the power supply through the fifth resistor a pin, the first end of the fourth electronic switch is connected to the first output pin of the power supply through the sixth resistor, the second end of the fourth resistance switch is grounded, and the first end of the fourth electronic switch is further Connected to the control end of the fifth electronic switch, the first end of the fifth electronic switch is connected to the power-on signal output pin of the power-on button, the second end of the fifth electronic switch is grounded, and the control end of the fifth electronic switch is further Connect the first An anode of the diode, a cathode of the second diode is connected to a cathode of the first diode; and when the control ends of the first to fifth electronic switches receive a high level signal, the first to fifth electrons The first end and the second end of the switch are respectively turned on. When the control ends of the first to fifth electronic switches receive the low level signal, the first ends and the second ends of the first to fifth electronic switches are disconnected.

The switch test circuit controls whether the motherboard is powered on by using the first and second electronic switches, and controls whether the motherboard is turned off by using the third to fifth electronic switches, so that the loop is reciprocated to simulate the host. The board is switched on and off to reduce manpower requirements.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a circuit diagram of a preferred embodiment of a switch test circuit of the present invention.

Please refer to FIG. 1 , the switch test circuit 100 of the present invention is used for performing a switch test on a motherboard 10 , and the switch test circuit 100 is connected to the boot signal output pin P of the boot button 20 on the motherboard 10 and the host. Between the output pins P3 of the board's Video Graphics Array (VGA) connector 40.

The motherboard 10 is also connected to a power supply 30 for powering the motherboard 10. The power-on signal output pin P of the power-on button 20 is connected to the control pin B of the power supply 30, and the ground pin GND of the power-on button 20 is grounded. When the power supply 30 is connected to the mains, the output pin A2 of the power supply 30 outputs a 5V_STBY power supply. When the power-on button 20 is pressed, the power-on signal output pin P of the power-on button 20 outputs a momentary low-level signal to the control pin B of the power supply 30, and the output pin A1 of the power supply 30 A 5V_SYS power supply is output and power is supplied to the motherboard 10, and the motherboard 10 is powered on. When the power-on button 20 is pressed for more than the low-level shutdown requirement of the motherboard 10 (4 seconds in this embodiment), the power-on signal output pin P of the power-on button 20 outputs a low power of 4 seconds. The signal signal is given to the control pin B of the power supply 30. The output pin A1 of the power supply 30 stops outputting the 5V_SYS power supply while stopping the power supply to the motherboard 10. The motherboard 10 is turned off.

The preferred embodiment of the switch test circuit 100 includes an electronic switch (in the present embodiment, field effect transistors Q1, Q4, Q5 and transistors Q2, Q3), resistors R1-R6, capacitors C1-C3, and two poles. Body D1, D2. The output pin A1 of the power supply 30 is connected to the gate of the field effect transistor Q1 through the resistor R1. The gate of the field effect transistor Q1 is also grounded through the capacitor C1. The drain of the field effect transistor Q1 The output pin A2 of the power supply 30 is connected through the resistor R2, and the source of the field effect transistor Q1 is grounded. The drain of the field effect transistor Q1 is grounded through the capacitor C2 and connected to the base of the transistor Q2. The base of the transistor Q2 is connected to the start signal output pin P of the power button 20, and the transistor Q2 is shot. Extremely grounded.

The output pin P3 of the VGA connector 40 is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the base of the transistor Q3 through the resistor R3. The base of the transistor Q3 is transmitted through the resistor R4. The output pin A1 of the power supply 30 is connected, and the emitter of the transistor Q3 is grounded. The base of the transistor Q3 is also connected to the gate of the field effect transistor Q4 through the capacitor C3. The gate of the field effect transistor Q4 is also connected to the output pin A1 of the power supply 30 through the resistor R5. The drain of the field effect transistor Q4 is connected to the output pin A1 of the power supply 30 through the resistor R6, and the source of the field effect transistor Q4 is grounded. The drain of the field effect transistor Q4 is also connected to the gate of the field effect transistor Q5. The drain of the field effect transistor Q5 is connected to the turn-on signal output pin P of the power-on button 20, and the field effect transistor Q5 The source is grounded. The gate of the field effect transistor Q5 is also connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the cathode of the diode D1. When the motherboard 10 is powered on, the output pin P3 of the VGA connector 40 outputs a short high level signal.

The working principle of the above-mentioned switch test circuit 100 will be described below:

In use, after the motherboard 10 is not powered on and the power supply 30 is connected to the mains, the output pin A2 of the power supply 30 continuously outputs a 5V_STBY power signal, and the base of the transistor Q2 is received from the power supply. The 5V_STBY power signal output from the output pin A2 of 30 is turned on. At this time, the base of the transistor Q2 outputs a low level signal. The control pin B of the power supply 30 receives the low level signal from the base of the transistor Q2 and turns on and outputs 5V_SYS power through its output pin A1. The gate of the field effect transistor Q1 receives the 5V_SYS power signal and is turned on. The base of the transistor Q2 receives the low level signal from the drain of the field effect transistor Q1 and is turned off, and the base of the transistor Q2 stops outputting. The low level signal, the control pin B of the power supply 30 receives the instantaneous low level signal from the base of the transistor Q2 to start supplying power to the motherboard 10, and the motherboard 10 is powered on.

After the motherboard 10 is powered on, the output pin P3 of the VGA connector 40 outputs a momentary high level signal. When the output pin P3 outputs a high level signal, the base of the transistor Q3 receives a high level signal and is turned on, and the output pin A1 of the power supply 30 starts to charge the capacitor C3 through the resistor R5. . The level signal of the gate of the field effect transistor Q4 is instantaneously changed from a high level to a low level, and then the drain and source of the field effect transistor Q4 are turned off, and the gate of the field effect transistor Q5 is turned off. The pole receives the 5V_SYS power signal from the output pin A1 of the power supply 30 to be turned on again, and the control pin B of the power supply 30 begins to receive a low level signal from the drain of the field effect transistor Q5. At the same time, the output pin A1 of the power supply 30 outputs a 5V_SYS power signal to the base of the transistor Q3 via the diode D2. Since the signal outputted by the output pin P3 of the VGA connector 40 is an instantaneous high level signal, when the signal outputted by the output pin P3 changes from a high level to a low level, the base of the transistor Q3 receives the received signal. The 5V_SYS power signal outputted by the output pin A1 of the power supply 30 causes the transistor Q3 to remain conductive.

When the capacitor C3 turns on the field effect transistor Q4 during charging, the gate of the field effect transistor Q5 receives a low level signal from the drain of the field effect transistor Q4, and the field effect is turned off. The drain of crystal Q5 stops outputting a low level signal. At the same time, the base of the transistor Q3 stops receiving the high level signal and turns off. The capacitance value of the capacitor C3 and the resistance value of the resistor R5 are set such that the time period from the off to the on time of the field effect transistor Q4 is 4 seconds, so that the control pin B of the power supply 30 receives a low level of 4 seconds. Signal, the output pin A1 of the power supply 30 stops outputting the 5V_SYS power supply and stops supplying power to the motherboard 10, and the motherboard 10 is turned off. The capacitor C3 is discharged through the resistor R5 to prepare for the next switch test.

After the motherboard 10 is turned off, the output pin A2 of the power supply 30 continuously outputs a 5V_STBY power signal. The capacitor C1 starts to discharge through the resistor R1, and the field effect transistor Q1 is turned on at this time. When the voltage of the capacitor C1 is less than the turn-on voltage of the field effect transistor Q1, the field effect transistor Q1 is turned off by conduction, and the base of the transistor Q2 receives the output of the output pin A2 from the power supply 30. The 5V_STBY power signal is turned on. Further, the base of the transistor Q2 outputs a low level signal to the power supply 30. The control pin B of the power supply 30 receives the low level signal and then turns on and outputs 5V_SYS power through the output pin A1. . The gate of the field effect transistor Q1 receives the 5V_SYS power signal and is turned on. The base of the transistor Q2 receives the low level signal from the drain of the field effect transistor Q1 and turns off, and the base of the transistor Q2 stops. The low level signal is output, and the control pin B of the power supply 30 receives the instantaneous low level signal from the base of the transistor Q2 to start supplying power to the motherboard 10. The motherboard 10 is turned on again.

The switch test circuit 100 controls whether the motherboard 10 is powered on by using the field effect transistor Q1 or the transistor Q2, and controls whether the motherboard 10 is turned off by using the transistor Q3 or the field effect transistors Q4 and Q5. The reciprocating loop is thus performed to simulate the on/off operation of the motherboard 10 to test the on/off of the motherboard.

As can be seen from the above description, the field effect transistors Q1, Q4, Q5 and the transistors Q2, Q3 both function as electronic switches. In other embodiments, the field effect transistors Q1, Q4, Q5 and the transistor Q2 and Q3 can also be replaced by other electronic switches.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or variations in accordance with the spirit of the present invention. It should be covered by the following patent application.

100‧‧‧Switching machine test circuit

10‧‧‧ motherboard

20‧‧‧Power button

30‧‧‧Power supply

40‧‧‧ VGA connector

Q1, Q4, Q5‧‧‧ field effect transistor

Q2, Q3‧‧‧ transistor

R1-R6‧‧‧ resistance

C1-C3‧‧‧ capacitor

D1, D2‧‧‧ diode

no

100‧‧‧Switching machine test circuit

10‧‧‧ motherboard

20‧‧‧Power button

30‧‧‧Power supply

40‧‧‧ VGA connector

Q1, Q4, Q5‧‧‧ field effect transistor

Q2, Q3, ‧‧ ‧ transistors

R1-R6‧‧‧ resistance

C1-C3‧‧‧ capacitor

D1, D2‧‧‧ diode

Claims (6)

A switch test circuit for testing a switchboard of a motherboard, the motherboard is also connected to a power supply, the power supply is used to supply power to the motherboard, and the test circuit of the switch is connected to the motherboard Between the boot signal output pin of the button and the output pin of the video graphics array connector on the motherboard, the boot signal output pin of the power button is connected to the control pin of the power supply, and the switch test circuit includes First to fifth electronic switches, first to sixth resistors, first and second capacitors, and first and second diodes, the first output pin of the power supply is transmitted through the first resistor and the first The control end of the electronic switch is connected to the control terminal of the first electronic switch, and the first end of the first electronic switch is connected to the second output pin of the power supply through the second resistor. The first end of the first electronic switch is connected to the control end of the second electronic switch, and the first end of the second electronic switch is connected to the boot of the power button An output pin, the second end of the second electronic switch is grounded, and a first output pin of the video graphics array connector on the motherboard is connected to an anode of the first diode, a cathode of the first diode Connecting the third electronic switch to the control end of the third electronic switch, the first end of the third electronic switch is connected to the first output pin of the power supply through the fourth resistor, and the second end of the third electronic switch Grounding, the first end of the third electronic switch is further connected to the control end of the fourth electronic switch through the second capacitor, and the control end of the fourth electronic switch is further connected to the first output of the power supply through the fifth resistor a pin, the first end of the fourth electronic switch is connected to the first output pin of the power supply through the sixth resistor, the second end of the fourth resistance switch is grounded, and the first end of the fourth electronic switch is further Connected to the control end of the fifth electronic switch, the first end of the fifth electronic switch is connected to the power-on signal output pin of the power-on button, the second end of the fifth electronic switch is grounded, and the control end of the fifth electronic switch is further Connect the first An anode of the diode, a cathode of the second diode is connected to a cathode of the first diode; and when the control ends of the first to fifth electronic switches receive a high level signal, the first to fifth electrons The first end and the second end of the switch are respectively turned on. When the control ends of the first to fifth electronic switches receive the low level signal, the first ends and the second ends of the first to fifth electronic switches are disconnected. The switch test circuit of claim 1, further comprising a third capacitor, wherein the control end of the second electronic switch is grounded through the third capacitor. The switch test circuit of claim 1, wherein the capacitance value of the second capacitor and the resistance value of the fifth resistor cause the power supply to charge the second capacitor to be electrically connected to the fourth electronic switch. The time meets the low-level shutdown requirement of the motherboard. The switch test circuit of claim 3, wherein the fourth electronic switch is turned on for 4 seconds. The switch test circuit of claim 1, wherein the first, fourth and fifth electronic switches are N-channel field effect transistors, gates, drains and sources of the N-channel field effect transistors The poles respectively correspond to the control ends, the first ends and the second ends of the first, fourth and fifth electronic switches. The switch test circuit of claim 1, wherein the second and third electronic switches are NPN transistors, and the base, the emitter and the base of the NPN transistor correspond to the second and third electrons, respectively. The control end, the first end and the second end of the switch.