Abstract: A safe electric power regulating circuit is connected between a power supply and a voltage boost/buck circuit to regulate the output voltage by the power supply to have a target voltage through the voltage boost/buck circuit. A switching device includes a switch unit, a first diode, and a first capacitor. The switch unit includes a first end, a second end, and a third end. The first end is connected to the power supply, and the second end is connected to the voltage boost/buck circuit. The switch unit is controlled to connect the third end to the first end or the second end. The first diode has an anode connected to the first end of the switch unit. The first capacitor has one end connected to the third end of the switch unit and the other end connected to circuit ground.

Abstract: A capacitive touch sensing device by detecting induced electric field includes a differential amplifier, a resistor and a signal judgment circuit. The differential amplifier is electrically connected to a touch sensor. The resistor is electrically connected to a first input end and a second input end of the differential amplifier. The signal judgment circuit is electrically connected to an output end of the differential amplifier. As the touch sensor receives an induced electric field signal, the induced electric field signal is amplified by the differential amplifier and the signal judgment circuit determines whether the amplified induced electric field signal is a touch input.

Abstract: A minute impedance variation detection device includes a differential amplifier, first and second impedances, a sensing electrode and a signal source. The differential amplifier has first and second input ends and an output end. The first impedance is connected to the first input end. The second impedance is connected to the second input end. The sensing electrode is connected to the second input end for sensing a touch and thus receiving a touch signal. The signal source is connected to the first impedance and the second impedance for providing an input signal inputted to the first impedance and the second impedance. The first impedance has an impedance value close to that of the second impedance. The differential amplifier is based on the input signal and the touch signal to differentially amplify the touch signal.

Abstract: A minute impedance variation detection device includes a differential amplifier, first and second impedances, a sensing electrode and a signal source. The differential amplifier has first and second input ends and an output end. The first impedance is connected to the first input end. The second impedance is connected to the second input end. The sensing electrode is connected to the second input end for sensing a touch and thus receiving a touch signal. The signal source is connected to the first impedance and the second impedance for providing an input signal inputted to the first impedance and the second impedance. The first impedance has an impedance value close to that of the second impedance. The differential amplifier is based on the input signal and the touch signal to differentially amplify the touch signal.