Abstract: A computer power supply unit with output mode determining function includes a voltage difference amplification circuit, a comparison circuit, a linear voltage regulator circuit, a drive circuit and a clamp circuit. A diode is disposed between the first and second input ends of the voltage difference amplification circuit. According to whether the diode generates turn-on bias, the voltage difference amplification circuit outputs a first voltage level. According to the first voltage level and the value of the constant voltage, the comparison circuit outputs a second voltage level. According to the value of the second voltage level, the drive circuit drives or does not drive the clamp circuit so as to judge the output mode of the power supply unit.

Abstract: A power coupling device with detection and power adjustment function includes at least one detection unit, at least one switch unit, at least one coupling unit, at least one amplification unit, at least one comparison unit and at least one logic unit. The detection unit serves to receive a first operation power and a second operation power. The coupling unit serves to couple the first and second operation powers for a power output end to output a regulated output power. The comparison unit serves to compare to generate a first comparison result and a second comparison result. According to the first and second comparison results, the logic unit logically judges to generate a triggering signal for controlling the switch unit to turn on or turn off the switch unit so as to adjust the power of the regulated output power.

Abstract: An ATX dual-output power supply unit with buck detection compensation ability has a voltage compensation unit connected to a first motherboard and a second motherboard. The power supply unit includes a circuit buck detection unit, a switch buck detection unit, a summarizing unit and a gain-lag comparison unit. The circuit buck detection unit serves to detect the circuit voltage loss between the first and second motherboards to output a circuit loss signal. The switch buck detection unit serves to detect the switch voltage loss between the power supply unit and the first and second motherboards to output a switch loss signal. The summarizing unit serves to summarize the circuit loss signal and the switch loss signal to generate a total buck loss signal. According to the total buck loss signal, the gain-lag comparison unit drives the voltage compensation unit to perform voltage compensation.

Abstract: A fan rotation speed controlling device includes a first transistor, a second transistor, a third transistor, a fourth transistor, and at least one heat dissipation fan. The first transistor receives a pulse-width modulation (PWM) signal. The second transistor and the third transistor amplify the PWM signal. The fourth transistor receives the amplified PWM signal and changes its own working state according to the amplified PWM thereby controlling the magnitude of an output voltage. Consequently, the heat dissipation fan changes its rotation speed according to variation of the output voltage. The fan rotation speed controlling device is applicable to and can control the rotation speeds of a plurality of electrically connected fans which are of different specifications.

Abstract: A fan rotation speed controlling device includes a first transistor, a second transistor, a third transistor, a fourth transistor, and at least one heat dissipation fan. The first transistor receives a pulse-width modulation (PWM) signal. The second transistor and the third transistor amplify the PWM signal. The fourth transistor receives the amplified PWM signal and changes its own working state according to the amplified PWM thereby controlling the magnitude of an output voltage. Consequently, the heat dissipation fan changes its rotation speed according to variation of the output voltage. The fan rotation speed controlling device is applicable to and can control the rotation speeds of a plurality of electrically connected fans which are of different specifications.