TWI385406B - Motherboard testing apparatus - Google Patents

Description

Motherboard test device

The invention relates to a motherboard testing device, in particular to a motherboard testing device capable of performing a loop switch test on a computer motherboard.

In the process of verifying the quality of the computer by the computer manufacturer, the DC Power on/off test of the computer motherboard, that is, the DC switch test is an important verification project. The test method is that the tester manually presses the computer power button periodically to make the computer main board power on, and the essence of manually pressing the computer power button is to give the input and output controller on the computer motherboard a low level signal, and let go. After the computer power button is pressed, the input/output controller is set back to a high level, thereby completing the computer booting. After the computer is turned on, the test program is executed. When the computer is turned on for a certain period of time, the tester manually operates the computer to softly shut down. When the computer is turned off for a while, press the power button of the computer again, and then cycle the operation of the switch machine until the number of tests reaches a predetermined number of times and then stop the test. In order to complete this test, it takes a lot of manpower and increases production costs.

In view of the above, it is necessary to provide a low-cost motherboard test device that can automatically perform a loop switch test on a computer motherboard.

A motherboard testing device includes: a pulse signal generating circuit, comprising: an input end and an output end, the input end receiving a standby voltage signal, and generating a pulse signal at the output end; a first control circuit, The method includes a first transistor, a second transistor, a third transistor, a field transistor, a diode, a first resistor, a second resistor, a third resistor, and a first capacitor. a base of the first transistor is connected to an output end of the pulse signal generating circuit, a collector of the first transistor is connected to a base of the second transistor, and an emitter of the first transistor is grounded, the second The collector of the transistor is connected to an input/output controller on a computer motherboard, the emitter of the second transistor is connected to the collector of the third transistor, and the emitter of the third transistor is grounded, the third transistor The base is connected to the drain of the field effect transistor, and receives the standby voltage signal through the second resistor. The source of the field effect transistor is grounded, and the gate of the field effect transistor is grounded through the first capacitor and transmitted through The third resistor is connected to the cathode of the diode The anode of the diode receives the system voltage signal of the motherboard, and the first control circuit outputs a first control signal to the input/output controller, and the input/output controller controls the first control signal after receiving the low level. The computer is powered on; and a second control circuit includes a first input end, a second input end, and an output end, the first input end receives the standby voltage signal, and the second input end receives the system voltage signal, The output end of the second control circuit is connected to the gate of the field effect transistor, and after the soft shutdown, the second control circuit outputs a second control signal to the first control circuit, so that the first control circuit receives the low After the pulse signal of the level, it can be turned on again.

Compared with the prior art, the motherboard testing device can manually control the power on and off of the computer to be tested without the test personnel, and control the high and low level signals output by the first control circuit to the input and output controller through the pulse signal. The motherboard performs automatic loop switch test, which is simple in circuit, low in cost and easy to implement.

Referring to FIG. 1, a preferred embodiment of the motherboard testing apparatus of the present invention includes a pulse signal generating circuit 10, a first control circuit 20, and a second control circuit 30.

The pulse signal generating circuit 10 includes a 555 timer U1, two resistors R6 and R7, and two capacitors C3 and C4. The 555 timer U1 includes a power terminal 11, a low trigger terminal 12, and a clear terminal 13. A control terminal 14, a high trigger terminal 15, a discharge terminal 16, an output terminal 17, and a ground terminal 18. The power terminal 11 is connected to the clear terminal 13 and connected to a 5V_STBY voltage of a computer motherboard to be tested. The low trigger terminal 12 is connected to the high trigger terminal 15 and grounded via the capacitor C3, and connected to the 5V_STBY through the resistors R6 and R7. The voltage is connected to the connection node between the resistors R6 and R7, and the control terminal 14 is grounded through the capacitor C4.

The first control circuit 20 includes three transistors T1, T2, T3, a field effect transistor Q1, a diode D1, five resistors R1, R2, R3, R4, R5 and two capacitors C1, C2. The base of the transistor T1 is connected to the output terminal 17 of the 555 timer U1 through a resistor R4. The collector of the transistor T1 is connected to the base of the transistor T2, and the emitter of the transistor T1 is grounded. The collector of the transistor T2 is connected to an input/output controller on a computer motherboard. The collector of the transistor T2 is grounded via a capacitor C2, and is connected to the 5V_STBY voltage through a resistor R5. The emitter of the transistor T2 is the same as the transistor. The collectors of T3 are connected. The emitter of the transistor T3 is grounded, and the base of the transistor T3 is connected to the drain of the field effect transistor Q1, and is connected to the 5V_STBY voltage through the second resistor R2. The source of the field effect transistor Q1 is grounded. The gate of the field effect transistor Q1 is grounded via a capacitor C1 and connected to the cathode of the diode D1 through a resistor R3. The anode of the diode D1 is connected to the motherboard. 5V_SYS voltage.

The second control circuit 30 includes a comparator U2, a transistor T4, and four resistors R8, R9, R10, and R11. The non-inverting input terminal of the comparator U2 is connected to the 5V_STBY voltage via a resistor R8, and is grounded through a resistor R9. The inverting input terminal of the comparator U2 is connected to the 5V_SYS voltage, and the output terminal of the comparator U2 is connected to the base of the transistor T4 through a resistor R10. The collector of the transistor T4 is connected to the field effect transistor Q1 through a resistor R11. The gate of the transistor T4 is grounded. Among them, the transistors T1, T2, T3, and T4 are all NPN type transistors, and the field effect transistor Q1 is an N-channel MOS type field effect transistor.

When testing the computer motherboard to be tested by using the motherboard test device of the present invention, first connect the power supply of the motherboard to the mains and close its switch, and the motherboard to be tested outputs the 5V_STBY voltage. The 5V_STBY voltage charges the capacitor C3 through the resistor R6 and the resistor R7. Before the voltage on the capacitor C3 is charged to two-thirds of the 5V_STBY voltage, the output terminal 17 of the 555 timer U1 always outputs a high level signal. When the voltage on the capacitor C3 is charged to two-thirds of the 5V_STBY voltage, the capacitor C3 is discharged through the resistor R7 to the discharge terminal 16 of the 555 timer U1, and the output terminal 17 of the 555 timer U1 outputs a low level. . The capacitor C3 is continuously charged and discharged to generate a pulse wave signal at the output end 17 of the 555 timer U1. When the output terminal 17 of the 555 timer U1 outputs a low level, at this time, since the 5V_SYS voltage has not been output, the gate of the field effect transistor Q1 is turned off at a low level, and the base of the transistor T3 is extremely high and turned on. The base of the transistor T1 is extremely low-cut, so that the base of the transistor T2 is extremely high and turned on, and the set of the transistor T2 is extremely low, which is equivalent to the tester manually pressing the power button. When the input/output controller receives the low level signal, the system voltages of each group are output so that the main body of the test board is powered, and the 5V_SYS voltage is charged to the capacitor C1 through the diode D1 and the resistor R3, and the voltage on the capacitor C1 is charged to the field. After the on-voltage of the transistor Q1 is turned on, the field effect transistor Q1 is turned on, so that the base of the transistor T3 is turned off at a low level, and the transistor T2 is also turned off. At this time, the tester has released the power button. This completes the automatic booting of the computer.

After the computer is turned on for a preset time, the input/output controller sends a shutdown signal to make the computer softly shut down. At this time, the 5V_SYS voltage is turned off, but the 5V_STBY voltage is still output. The output terminal of the comparator U2 outputs a high level such that the transistor T4 is turned on, and the capacitor C1 is discharged through the resistor R11. When the voltage on the capacitor C1 is placed to the cutoff voltage of the field effect transistor Q1, the field effect transistor Q1 is turned off again, and the transistor T3 is turned on again. When the output terminal 17 of the 555 timer U1 outputs a low level again, the transistor T2 can also be turned on again, and the computer can be turned on again. Therefore, the high-low pulse signal continuously outputted by the output terminal 17 of the 555 timer U1 realizes the loop switch test of the motherboard to be tested.

The motherboard test device can automatically perform loopback switch test on the computer motherboard, and has the advantages of simple structure, strong practicability and low cost.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above-mentioned embodiments are only the specific embodiments of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

Pulse signal generation circuit. . . 10

First control circuit. . . 20

Second control circuit. . . 30

555 timer. . . U1

Comparators. . . U2

Crystal. . . T1~T4

Field effect transistor. . . Q1

Diode. . . D1

resistance. . . R1~R11

capacitance. . . C1~C4

1 is a circuit diagram of a preferred embodiment of a motherboard test apparatus of the present invention.

Pulse signal generation circuit. . . 10

First control circuit. . . 20

Second control circuit. . . 30

555 timer. . . U1

Comparators. . . U2

Crystal. . . T1~T4

Field effect transistor. . . Q1

Diode. . . D1

resistance. . . R1~R11

capacitance. . . C1~C4

Claims (7)

A motherboard testing device includes: a pulse signal generating circuit, comprising: an input end and an output end, the input end receiving a standby voltage signal, and generating a pulse signal at the output end; a first control circuit, The method includes a first transistor, a second transistor, a third transistor, a field transistor, a diode, a first resistor, a second resistor, a third resistor, and a first capacitor. a base of the first transistor is connected to an output end of the pulse signal generating circuit, a collector of the first transistor is connected to a base of the second transistor, and an emitter of the first transistor is grounded, the second The collector of the transistor is connected to an input/output controller on a computer motherboard, the emitter of the second transistor is connected to the collector of the third transistor, and the emitter of the third transistor is grounded, the third transistor The base is connected to the drain of the field effect transistor, and receives the standby voltage signal through the second resistor. The source of the field effect transistor is grounded, and the gate of the field effect transistor is grounded through the first capacitor and transmitted through The third resistor is connected to the cathode of the diode The anode of the diode receives the system voltage signal of the motherboard, and the first control circuit outputs a first control signal to the input/output controller, and the input/output controller controls the first control signal after receiving the low level. The computer is powered on; and a second control circuit includes a first input end, a second input end, and an output end, the first input end receives the standby voltage signal, and the second input end receives the system voltage signal, The output end of the second control circuit is connected to the gate of the field effect transistor, and after the soft shutdown, the second control circuit outputs a second control signal to the first control circuit, so that the first control circuit receives the low After the pulse signal of the level, it can be turned on again. The motherboard test apparatus of claim 1, wherein the first control circuit further includes a fourth resistor connected to the output end of the pulse signal generating circuit and the base of the first transistor. between. The motherboard test apparatus of claim 1, wherein the first control circuit further includes a fifth resistor and a second capacitor, and the collector of the second transistor receives the standby voltage signal via the fifth resistor. And grounded through the second capacitor. The motherboard testing device of claim 1, wherein the pulse signal generating circuit comprises a 555 timer, a sixth resistor, a seventh resistor, a third capacitor and a fourth capacitor, the 555 The timer includes a power terminal, a low trigger terminal, a clear terminal, a control terminal, a high trigger terminal, a discharge terminal and an output terminal, and the power terminal serves as an input end of the pulse signal generating circuit and a clear terminal. Connected, the low trigger end is connected to the high trigger end, grounded through the third capacitor, and receives the standby voltage signal through the sixth resistor and the seventh resistor, and the discharge end is connected to the connection node between the sixth resistor and the seventh resistor The control terminal is grounded through the fourth capacitor, and the output end of the 555 timer serves as an output end of the pulse signal generating circuit. The motherboard testing device of claim 4, wherein the second control circuit comprises a comparator, a fourth transistor, an eighth resistor, a ninth resistor, a tenth resistor, and a tenth a resistor, the non-inverting input of the comparator as the first input end of the second control circuit receives the standby voltage signal via the eighth resistor, and is grounded through the ninth resistor, and the inverting input of the comparator serves as the second control circuit a second input end, the output end of the comparator is connected to the base of the fourth transistor through a tenth resistor, and the collector of the fourth transistor is connected to the field through the eleventh resistor as an output end of the second control circuit The gate of the transistor, the emitter of the fourth transistor is grounded. The motherboard test apparatus of claim 5, wherein the first, second, third, and fourth transistors are all NPN type transistors. The motherboard test apparatus of claim 1, wherein the field effect transistor is an N-channel MOS type field effect transistor.