Abstract: A power supply for a computer includes a transformer, a rectifier, a pulse width modulation (PWM) controller, a relay, a power switch, and a battery. The PWM controller includes a voltage terminal and a pulse terminal. The relay includes a switch and an inductance coil. An alternating current (AC) power supply is connected to a primary inductance coil of the transformer via the rectifier. A secondary inductance coil of the transformer provides a standby voltage. A positive voltage terminal of the rectifier is connected to the pulse terminal of the PWM controller via the primary inductance coil of the transformer. The switch is connected between the positive voltage terminal of the rectifier and the voltage terminal of the PWM controller. The inductance coil and the power switch are connected in series between the battery and ground. The power switch is controlled by powering on or off the computer.

Abstract: A power supply for a computer includes a transformer, a rectifier, a pulse width modulation (PWM) controller, a relay, a power switch, and a battery. The PWM controller includes a voltage terminal and a pulse terminal. The relay includes a switch and an inductance coil. An alternating current (AC) power supply is connected to a primary inductance coil of the transformer via the rectifier. A secondary inductance coil of the transformer provides a standby voltage. A positive voltage terminal of the rectifier is connected to the pulse terminal of the PWM controller via the primary inductance coil of the transformer. The switch is connected between the positive voltage terminal of the rectifier and the voltage terminal of the PWM controller. The inductance coil and the power switch are connected in series between the battery and ground. The power switch is controlled by powering on or off the computer.

Abstract: A testing circuit for an interface includes a load feeding circuit and a voltage testing circuit. The load feeding circuit includes a resistance-regulating unit, a first comparator, a pass element, and a capacitor. The resistance-regulating unit is connected to a positive input of the first comparator. A negative input of the first comparator is connected to the capacitor and a first terminal of the pass element. An output of the first comparator is connected to a second terminal of the pass element. A third terminal of the pass element is connected to the interface. The voltage testing circuit includes a second comparator and a display member connected to the second comparator. The voltage of the interface and a reference voltage are input to inputs of the second comparator, and the second comparator outputs a signal to control the display member to display a comparison result.

Abstract: A testing circuit for an interface includes a load feeding circuit and a voltage testing circuit. The load feeding circuit includes a resistance-regulating unit, a first comparator, a pass element, and a capacitor. The resistance-regulating unit is connected to a positive input of the first comparator. A negative input of the first comparator is connected to the capacitor and a first terminal of the pass element. An output of the first comparator is connected to a second terminal of the pass element. A third terminal of the pass element is connected to the interface. The voltage testing circuit includes a second comparator and a display member connected to the second comparator. The voltage of the interface and a reference voltage are input to inputs of the second comparator, and the second comparator outputs a signal to control the display member to display a comparison result.