| 摘要 |
PROBLEM TO BE SOLVED: To optimize comprehensive efficiency including a chopper smoothing circuit and a high-frequency generation circuit, substantially equalize negative electrode potentials of both circuits, and reduce noise failures by having a pressure-rise type chopper smoothing circuit at a front stage and a pressure-fall type chopper circuit at a back stage. SOLUTION: A chopper smoothing circuit 3 comprises a pressure-rise type chopper circuit 3a with an inductance L1 , a switching element Q1 , a diode D1 , and a condenser C1 , at a back stage of which the circuit 3 comprises a pressure- fall type chopper circuit 3b with a switching element Q2 , an inductor L2 , and a smoothing condenser C2 . Pressure is risen by the circuit 3a higher than an AC power voltage, and a voltage of the circuit 3a is pressure-fallen by the circuit 3b. An output voltage Vdc of the circuit 3 is set in the vicinity of a peak value from the effective value of the AC power voltage. A negative electrode G1 of a rectification circuit 2 and a negative electrode G2 of a high-frequency generation circuit 4 have the same potentials, and there are eliminated problems such as noise failure due to generation of a high-frequency voltage at the negative electrode G2 of the circuit 4 and unstable operation. |
