| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems that the work of adjusting power supply voltage to the reference voltage by changing the value of resistance of semi fixed resistance takes too much time and that the structure becomes too complex in preparation of plural stages of power supply voltage. SOLUTION: In order to make a control means 12 detect the voltage of direct current power supply and to set a reference voltage part 13 to the desired reference voltage by changing the voltage of an interconnecting part 11a, the control voltage is produced and outputted to the interconnecting part 11a. Then the change of voltage at the interconnecting part 11a will be transmitted to the reference voltage part 13 through a resistant circuit and its voltage will be changed from the power supply voltage responding to the changed voltage at the interconnecting part 11a, and the voltage of the reference voltage part 13 will be automatically adjusted to the desired reference voltage. And therefore, it becomes possible to adjust the power supply voltage automatically with simple structure and to make the adjustment work of power supply voltage unnecessary. |
