| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of a radiation fin to an electron circuit part for constituting a pressure up invertor circuit, by nearing electric power loss, in the pressure up invertor circuit at the time of 100V input, to electric power loss at the time of 200V input. SOLUTION: Detected output voltage; by an output voltage detection resistor 10 to which 200V is applied from a 200V power source, and an adjusting resistor 43 is connected in parallel; is compared with second reference voltage in a step-up control circuit 11 to control a step-up power MOSFET 7 from a resultant to increase the output voltage of a step-up invertor circuit 3 to a 350V degree. While when 100V, used in a 100V power source, is applied, rectification output at the time of 100V input is detected by an input voltage detection circuit 41, thereby to deenergize a step-up voltage switching relay 42, to open a relay contact 42a, to increase the output voltage of the circuit 3 to a 250V degree. Consequently, electric power loss at the time of 100V input in the circuit 3 can be restrained to a 20% degree of the electric power loss at the time of 200V input, thereby reducing the number of radiation fin of a step-up invertor part. |
