| 摘要 |
PURPOSE:To reduce the size, the weight and the cost by employing a circuit for controlling a power source formed on a chip with an output voltage controller and an AC signal generator to obtain a DC voltage. CONSTITUTION:A power source 101 of an electronic device has a circuit 100 for controlling a power source and a switching circuit 102 to obtain the desired voltage or constant-current output from a DC input voltage. In this case, a pulse-width modulation (PWM) controllers 105 and an AC voltage output unit 106 are provided in the circuit 100. Further, the both circuits are composed as integrated circuits (e.g., monolithic integrated circuits). Thus, the circuit 100 operates the circuit 102 by DC constant voltage output by a PWM control signal 103 output from the controller 105, and an AC output voltage 104 is output by an AC voltage output unit 106. The power source 101 is reduced in size and cost. |
