Abstract: A computer system on/off test apparatus includes a parameter setting and test control circuit, a test indicating circuit, a voltage converting circuit, and an on/off signal switch circuit. The parameter setting and test control circuit includes a micro control unit (MCU) to set a number of test times and control an on/off test of a motherboard. The test indicating circuit is operable to display the number set by the parameter setting and test control circuit, and display a successful number of test times of the on/off test. The voltage converting circuit is operable to convert a first voltage received from a first standby power connector to a second voltage. The on/off signal switch circuit is operable to switch the first and second voltages according the control by the MCU.

Abstract: A linear voltage regulator circuit includes first and second voltage input terminals to receive a first or second external voltage, a voltage output terminal, a voltage regulator unit, a voltage switch unit, and a voltage detecting unit. The voltage regulator unit selectively receives the first or second external voltage controlled by the voltage switch unit. The voltage detecting unit outputs a first control signal to control the voltage switch unit to output the first external voltage to the voltage regulator unit, in response to an output voltage of the voltage output terminal being less than or equal to a predetermined value. The voltage detecting unit outputs a second control signal to control the voltage switch unit to output the second external voltage to the voltage regulator unit in response to the output voltage being greater than the predetermined value.

Abstract: A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes an amplifier and a thermal diode. The detecting circuit detects temperature and outputs a voltage signal. The control circuit receives the voltage signal and controls the rotation rate of the fan according to the voltage signal.

Abstract: The lighting delay circuit can keep a light being on for a predetermined time then turn off the light. The circuit comprises a thermistor to sense temperature around the light when the light is on, an electronic switch controlled by the thermistor, and a relay controlled by the electronic switch to turn off the light when the electronic switch is turned on.

Abstract: A fan control circuit includes an integrated circuit (IC), a thermistor, and a transistor. A first input of the IC is connected to a fan power supply. A second input of the IC is connected to a stand-by power supply. A base of the transistor is grounded through the thermistor. An emitter of the transistor is connected to an output of the IC. A collector of the transistor is connected to a fan.

Abstract: The temperature control circuit, to keep a temperature of an enclosed space within a temperature range, comprises a cooling unit to keep the temperature of the enclosed space below a maximum temperature of the temperature range, a heating unit to keep the temperature of the enclosed space above the minimum temperature of the temperature range, and an indicating unit to indicate whether the temperature is within the temperature range.

Abstract: A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes a first amplifier, a second amplifier, and a thermistor. The control circuit includes a first terminal, a second terminal, and a third terminal. The detecting circuit detects temperature and outputs a voltage signal. The control circuit receives the voltage signal and controls the rotation rate of the fan according to the voltage signal.

Abstract: A circuit for controlling time sequence of an electronic device, the circuit comprises a delay unit to receive a first control signal, a first switch unit connected to the delay unit to receive the first control signal after a rising edge of the first control signal, a second switch unit to promptly receive the first control signal in response to a falling edge of the first control signal, and a voltage output unit connected to the first and second switch units. The voltage output unit is selectively controlled by the first or the second switch unit to output a second or a third control signal to turn on or off the electronic device.

Abstract: A protection circuit includes a switch and a transistor. A first end of the switch is connected to a power source. A second end of the switch is connected to an electronic device via a first resistor. A third end of the switch is connected to the power source via a second resistor. A base of the transistor is connected to the second of the transistor via a third resistor, and grounded via a fourth resistor. A collector of the transistor is connected to the power source. An emitter of the transistor is connected to the electronic device.

Abstract: A fan control system includes a linear adjustor, an input/output controller, and a temperature sensor. A first terminal of the linear adjustor is connected to a first power supply. A second terminal of the linear adjustor is connected to a fan and grounded via a first resistor and a second resistor in series. A third terminal of the linear adjustor is connected to a node between the first resistor and the second resistor. A first terminal of the input/output controller is connected to the third terminal of the linear adjustor via a third resistor. A second terminal of the input/output controller is connected to the temperature sensor.

Abstract: An ignition circuit includes a system power supply, an ignition coil, a delay unit, a first switch unit, and a second switch unit. When the system power supply is powered on, the second switch unit is turned on, the ignition coil is powered on. After a delay time, the delay unit controls the first switch unit to be turned on, the second switch unit is turned off, the ignition coil is powered off. Therefore an ignition operation is accomplished.

Abstract: An overcurrent protection circuit connected between a voltage input and a voltage output of an electronic device to protect against excessive current is disclosed. The overcurrent protection circuit includes first to fifth resistors, a relay comprising a coil and a normally closed switch, a pnp transistor, and a break-over element. When a current between the voltage input and the voltage output is greater or equal to a rated current of the electronic device, the npn transistor is turned on, while the coil is powered on to control the switch to be opened, therefore the voltage output cannot output voltage, which can protect against excessive current damaging the electronic device.

Abstract: A voltage measuring circuit includes an under-voltage measuring circuit and an over-voltage measuring circuit. The under-voltage measuring circuit includes a first voltage comparator, a first zener diode, and a first light emitting diode. An inverting input of the first voltage comparator is connected to a cathode of the first zener diode. An output of the first voltage comparator is connected to a cathode of the first light emitting diode. The over-voltage measuring circuit includes a second voltage comparator, a second zener diode, and a second light emitting diode. A non-inverting input of the second voltage comparator is connected to the cathode of the second zener diode. An output of the second voltage comparator is connected to a cathode of the second light emitting diode.

Abstract: A system and method for testing a computer divide test programs in a test file into hardware test programs and software test programs. A test server selects one or more test programs from the divided test file according to test parameters of the computer. The test server generates a test command for testing test items of the computer. The computer executes the test command. The test server analyzes test results and stores analyzed results into a predefined storage path.

Abstract: An under-voltage warning circuit includes a Zener diode, a transistor, an annunciator, and a thyristor. When the power source is within a certain range, the annunciator does not work. When the voltage level of the power source V_in is lower than the predetermined value, the annunciator works to denote that the power source is under-voltage.

Abstract: A system and method for testing different computer types sets test parameters of each computer type of the computers, and sends a test command to each computer to control each computer to test each test signal of the computer. The system and method further receives test result data collected by the computer, and compares the test result data with preset standard test result to determine if the test result data is acceptable.

Abstract: A circuit for controlling a rotation speed of a fan of an electronic device according to a temperature of the electronic device. The circuit senses the temperature of the electronic device, and outputs a voltage changing with the sensed temperature. The rotation speed of the fan changes with the voltage. The circuit slows the rotation speed of the fan down when the sensed temperature of the electronic device is decreased.

Abstract: A power supply control circuit includes a first switch unit comprising an input terminal to receive a control signal, and a number of second switch units. The second switch units are each connected between an input power source and a power output terminal. The first switch unit controls the number of second switch units to be turned on in response to the control signal being in a first status, so as to control the number of power output terminals to output corresponding power sources. The first switch unit controls the number of second switch units to be turned off in response to the control signal being in a second status, so as to direct the power output terminals to not output the corresponding power sources.

Abstract: A memory voltage control circuit includes two slots, a control circuit, a voltage conversion circuit, and a switch circuit. The two slots are able to efficiently process different memory types. The control circuit receives memory identification signals from the two slots. The control circuit administers the output voltage of the voltage conversion circuit according to the memory identification signals. The memory identification signals determine whether the switch circuit is to be turned on or off. This will control whether the output voltage of the voltage conversion circuit will go to the first or the second slot.

Abstract: A CPU power control circuit includes a temperature detection circuit, a power supply circuit and a discharge circuit. The power supply circuit is connected to the temperature detection circuit, a CPU and the discharge circuit. The discharge circuit is connected to the temperature detection circuit and the CPU. The temperature detection circuit is connected to the CPU for detecting the temperature of the CPU. When the temperature of the CPU exceeds a predetermined range, the temperature detection circuit outputs a high temperature signal. The power supply circuit receives the high temperature signal, and stops working. The discharge circuit receives the high temperature signal, and discharges the power supply circuit so as to stop supplying power to the CPU.