Abstract: An alarm clock includes a microcontroller, a display unit, an audio output unit, ten numeric keys and a functional key. Upon determining that a long-press operation is performed on one of the numeric keys that corresponds to a weekly alarm setting, the microcontroller performs a weekly alarm setting procedure for the corresponding weekly alarm setting. In the weekly alarm setting procedure, the microcontroller sets an alarm time based on some numeric keys that are pressed in a time-setting stage, and sets an alarm day based on at least one numeric key and the functional key that are pressed in a day-setting stage. Then, the microcontroller displays the alarm, time and the alarm day on the display unit.

Abstract: A switch mode power supply includes a PWM controller, a voltage converter, an output detector and a communicator. The PWM controller is to receive an actuation signal, and generates a PWM signal based on the actuation signal. The voltage converter is to receive the PWM signal and an external voltage, and converts, based on the PWM signal, the external voltage into first and second output voltages. The output detector is to receive the first and second output voltages, and generates an enable signal based on a target voltage value and a magnitude difference between the first and second output voltages. The communicator is to receive the enable signal, and generates the actuation signal corresponding to the enable signal.

Abstract: A switch mode power supply includes a PWM controller, a voltage converter, an output detector and a communicator. The PWM controller is to receive an actuation signal, and generates a PWM signal based on the actuation signal. The voltage converter is to receive the PWM signal and an external voltage, and converts, based on the PWM signal, the external voltage into first and second output voltages. The output detector is to receive the first and second output voltages, and generates an enable signal based on a target voltage value and a magnitude difference between the first and second output voltages. The communicator is to receive the enable signal, and generates the actuation signal corresponding to the enable signal.

Abstract: A charge and power supply circuit includes: a first switch coupled between a first node and a positive terminal of a battery; a second switch coupled between a USB connector and one of the first node and a second node; a third switch coupled to a load in series between the first and second nodes; and a control unit controlling the switches. In a USB charge mode, an input voltage from the USB connector is permitted to charge the battery via the conducting first and second switches. In a battery supply mode, the battery is permitted to supply a battery voltage to the load via the conducting first and third switches. In a USB supply mode, the input voltage is permitted to be supplied to the load via the conducting second and third switches.

Abstract: A charge and power supply circuit includes: a first switch coupled between a first node and a positive terminal of a battery; a second switch coupled between a USB connector and one of the first node and a second node; a third switch coupled to a load in series between the first and second nodes; and a control unit controlling the switches. In a USB charge mode, an input voltage from the USB connector is permitted to charge the battery via the conducting first and second switches. In a battery supply mode, the battery is permitted to supply a battery voltage to the load via the conducting first and third switches. In a USB supply mode, the input voltage is permitted to be supplied to the load via the conducting second and third switches.

Abstract: A voltage stabilizer receives a direct-current (DC) input voltage, and includes four resistors, two transistors, and a diode that cooperatively provide a stable DC output voltage. The voltage stabilizer is configured such that the diode does not directly receive the DC input voltage and does not conduct all the time, so as to reduce power consumption.

Abstract: A power conversion device includes a switched-mode power supply (SMPS), a photocoupler and a controller. The SMPS receives a pulse width modulation (PWM) signal from the controller to generate a DC output voltage related to a DC input voltage. The photocoupler generates a reference voltage signal based on the DC output voltage. The controller adjusts at least one of a duty cycle or a frequency of the PWM signal based on the reference voltage signal.

Abstract: A driving circuit of electrostatic adhesion board, using a DC power source to drive an electrostatic adhesion board, comprising: a N-channel MOS power transistor having characteristics of high current and low On-resistance; a transformer having a primary winding and a secondary winding, the primary winding connected between the power supply voltage node of the DC power source and the drain node of the power transistor, accepting the potential difference between power supply voltage node of the DC power source and the power transistor as a primary voltage, the secondary winding outputting a secondary voltage which is already transformed; a voltage multiplier having an input side coupled to the secondary winding of the transformer, accepting the secondary voltage as its input voltage, then enlarging and coupling as its output voltage to the electrostatic adhesion board; a main controller connected between the power supply voltage node and a ground node of the DC power source, having a control node connected to

Abstract: A voltage stabilizer receives a direct-current (DC) input voltage, and includes four resistors, two transistors, and a diode that cooperatively provide a stable DC output voltage. The voltage stabilizer is configured such that the diode does not directly receive the DC input voltage and does not conduct all the time, so as to reduce power consumption.