CIRCUIT DEVICE FOR SUPPLYING AT LEAST ONE LOAD WITH POWER

摘要

PROBLEM TO BE SOLVED: To obtain a circuit device which can prevent a load from being damaged by an overvoltage by constituting a service voltage source so that the source may generate a service voltage which can selectively set a lower service voltage value than a reference voltage and a higher service voltage value than the reference voltage. SOLUTION: A first signal processor 1 is provided in a telecommunication exchange and electric power is supplied to at least one additional signal processor 10 from the exchange. The processor 10 is connected to a second line terminal formed of line terminals 8 and 9 and has a terminal 11. It is necessary to transmit communication signals to the terminal 11 from the terminal 2 or to the terminal 2 from the terminal 11 while electric power is supplied only from the location of the first signal processor 1 during the operation of a circuit device. A service voltage source 12 is set at a larger value than a reference voltage value by operating the first chopper switch 18 of a control circuit 19. When no identification signal exists, a change-over switch 63 supplies a service voltage having a smaller value than the reference voltage value from the service voltage source 12 by operating the control circuit 19.