Abstract: A precision control device generally includes a current-limiting resistance, a voltage control unit, and a feedback voltage regulation unit. The current-limiting resistance has a grounded end and is serially connected to a DC load. The voltage control unit includes a microprocessor, an ADC, and a DAC. The feedback voltage regulation unit includes at least one operational amplifier and a transistor having a control input, a collector, and an emitter. The transistor is configured to operate at an unsaturated region, wherein the control input thereof receives a signal sent from an output terminal of the operational amplifier. The precision control device enables a power supply to smoothly adjust a predetermined output voltage set value for the DC load in response to a deviation of a voltage applied to the DC load. As such, the current flowing through the DC load and the current-limiting resistance can be regulated at a stable level.

Abstract: The problem of poor signal quality of biometric measurement is improved with a new headset construction. The new headset includes a sensor assembly that provides more stable and secure contact between the sensor electrodes and the scalp of the wearer of the headset. The sensor assembly includes a housing unit for the electrodes and has a flexible and collapsible wall portion, which flexes and deforms according to the strength and the location of the pressure applied to the electrodes to maximize the contact area between the scalp and the sensors.

Abstract: A precision control device generally comprises a current-limiting resistance, a voltage control unit, and a feedback voltage regulation unit. The current-limiting resistance has a grounded end and is serially connected to a DC load. The voltage control unit includes a microprocessor and a DAC. The feedback voltage regulation unit includes at least one operational amplifier and a transistor having a control input, a collector, and an emitter. The transistor is configured to operate at an unsaturated region, wherein the control input thereof receives a signal sent from an output terminal of the operational amplifier. The precision control device enables a power supply to smoothly adjust a predetermined output voltage set value for the DC load in response to a deviation of a voltage applied to the DC load. As such, the current flowing through the DC load and the current-limiting resistance can be regulated at a stable level.

Abstract: A sensor electrode device comprises a base and a plurality of flexible electrodes. The flexible electrodes protrude from one side of the base, detecting at least one physiological signal and sending out the physiological signal via the base. The flexible electrodes can expel hairs to directly contact the skin, whereby hairs would not hinder the sensor electrode device from detecting physiological signals. Further, the tips of the flexible electrodes bend under pressure to increase the area contacting the skin and improve the ability to detect physiological signals.