摘要:
A test circuit includes two probes, a comparison circuit, a switch circuit, and an indication circuit. The probes are connected to an electronic component to be tested, and a low level signal is output if the electronic component is short-circuited. The comparison circuit outputs a comparison signal based on the shorting signal from the probes. The switch circuit outputs a switch signal based on the comparison signal from the comparison circuit. The indication circuit indicates that the electronic component is short-circuited or not short-circuited based on the switch signal fro m the switch circuit.
摘要:
An overvoltage protection circuit includes a power device for outputting a plurality of first powers, a plurality of VRMs for respectively receiving the plurality of first powers, a plurality of voltage dividing circuits, a reference power supply for outputting a reference voltage, and a comparison circuit having a comparator. Each VRM converts a corresponding first power to a regulated second power. The plurality of voltage dividing circuits respectively divides voltages of the second powers, each voltage dividing circuit outputs a divided voltage. The comparator compares a combination of the divided voltages with the reference voltage, and when an overvoltage occurs in at least one of the second powers, the comparator outputs a control signal via the output terminal to the power device to control the power device to shut down all of the first powers.
摘要:
A connection circuit for a digital visual interface (DVI) includes a platform controller hub (PCH), a DVI, a plurality of voltage dividing resistors, and a switch. The platform controller hub (PCH) includes a plurality of output contacts outputting a plurality of analog signals. The DVI includes a plurality of input contacts, and each input contact is connected to one of the output contacts to transmit the analog signals. The switch has one end connected to the output contacts, and another end grounded. The switch switches on when a power supply is applied to the switch and is switched off when the power supply is not applied to the switch.
摘要:
A circuit for clearing complementary metal oxide semiconductor (CMOS) information of a CMOS chip includes a battery, first to fifth resistors, first and second electronic switches, a switching unit, and first and second diodes. The circuit can clear information of the CMOS chip when one or more switches are activated.
摘要:
A fast-discharge circuit includes at least one power supply group, a switch circuit, and a power connector. Each power supply group includes a power supply unit, stabilizing capacitances, a diode, and a resistance. The power supply unit includes a positive output and a negative output. Anodes of the stabilizing capacitances and the diode are connected to the positive output of the power supply unit. Cathodes of the stabilizing capacitances are connected to the negative output. A cathode of the diode is also connected to the negative output through the resistance. The switch circuit includes a NMOS transistor. A drain of the NMOS transistor is electrically connected to the negative outputs of each power supply; a source of the NMOS transistor is grounded. The power connector includes a PS-ON pin electrically connected to a gate of the NMOS transistor.
摘要:
A power supply circuit is configured for simulating the maximum standard load currents for different kinds of USB ports, and each of the USB ports includes a power terminal; the load-testing circuit includes a voltage regulating circuit, a voltage dividing circuit, a first operational amplifier, a first transistor, and a current limiting resistor. The voltage regulating circuit is configured for supplying a reference voltage to the voltage dividing circuit. The reference voltage is divided by sub-circuits of the voltage dividing circuit. When the sub-circuit connected to the voltage regulating circuit and the first operational amplifier is changed, a current flows from the first transistor and the current limiting resistor is changed.
摘要:
A charging circuit includes a switch, a standby power supply, a first power supply, a second power supply, a universal serial bus (USB) port, and a power supply switching module with a first to a fourth terminals. According to the power states of a computer, the power supply switching module allows either a first power supply or a second standby power supply to provide a charging voltage for the USB port through controlling the switch.
摘要:
An indicator light control circuit for controlling a single indicator light to indicate a high or low link speed of a network connection includes a pulse signal generating circuit, a bias circuit having a digital potentiometer, and a controller. The pulse signal generating circuit generates a pulse signal. The digital potentiometer is electronically connected to the pulse signal generating circuit and the controller. The controller adjusts the effective resistance of the digital potentiometer connected to the pulse signal generating circuit according to different link speeds being experienced in the network connection, to adjust a duty cycle of the pulse signal, thereby changing the on-time and off-time of the indicator light.
摘要:
A protection circuit that protects a load charged by a power supply. The protection circuit includes a reference voltage set circuit, a sampling circuit, a switch, and a comparator. The reference voltage set circuit provides a reference voltage. The sampling circuit is electrically connected to the power supply and provides a sampling voltage based on a charge voltage output from the power supply to the load. The switch is electrically connected between the power supply and the load. The comparator includes a non-inverting input terminal electrically connected to the reference voltage set circuit, an inverting input terminal electrically connected to the sampling circuit, and an output terminal electrically connected to the switch. The comparator compares the sampling voltage with the reference voltage, and controls the switch to turn on or off according to the comparison.
摘要:
A power supply system for an air conditioner of a car includes a battery, an alternator, a detection circuit to detect whether the alternator is operating and outputting a detection signal according to the detection result, a processing unit to output a control signal according to the detection signal, and a switching circuit to connect either the battery or the alternator to the air conditioner.