Abstract: A wireless rechargeable electronic device includes a body and a replaceable battery pack. The body includes a wireless charging control circuit. The replaceable battery pack includes a battery cell and a wireless charging induced circuit. The wireless charging induced circuit is adapted for generating an induced current, and the induced current is transmitted to the battery cell after passing through the wireless charging control circuit.

Abstract: A charging method and a charging system are introduced for controlling a charging current by a PWM method. A charging IC is controlled to supply the charging current to a battery, and a control unit is used to generate a PWM signal with a duty cycle, and a filter unit is used to convert the PWM signal into a voltage signal to be supplied to the charging IC, and the control unit determines whether a current of a battery detected by the battery status detection unit reaches a regular current, so that a PWM signal with a duty cycle greater than the previous duty cycle by a default increased cycle is provided if the detected current has not reached the regular current. Thus, the feature of the PWM signal is used to set the charging current according to the capacity of the battery automatically.

Abstract: A charging method and a charging system are introduced for controlling a charging current by a PWM method. A charging IC is controlled to supply the charging current to a battery, and a control unit is used to generate a PWM signal with a duty cycle, and a filter unit is used to convert the PWM signal into a voltage signal to be supplied to the charging IC, and the control unit determines whether a current of a battery detected by the battery status detection unit reaches a regular current, so that a PWM signal with a duty cycle greater than the previous duty cycle by a default increased cycle is provided if the detected current has not reached the regular current. Thus, the feature of the PWM signal is used to set the charging current according to the capacity of the battery automatically.

Abstract: An EMI-resistant circuit board assembly includes a plurality of circuit boards arranged in a stack and a metal shielding frame respectively sandwiched in between each two adjacent circuit boards. One of the circuit boards has at least one high-speed device producing high-frequency noises to the ambient, which result in EMI effect. The metal shielding frame is electrically connected to the ground potential of the circuit boards and shields the high-speed device on the circuit board to guide the high-frequency noises to the ground potential.

Abstract: An EMI-resistant circuit board assembly includes a plurality of circuit boards arranged in a stack and a metal shielding frame respectively sandwiched in between each two adjacent circuit boards. One of the circuit boards has at least one high-speed device producing high-frequency noises to the ambient, which result in EMI effect. The metal shielding frame is electrically connected to the ground potential of the circuit boards and shields the high-speed device on the circuit board to guide the high-frequency noises to the ground potential.