| 摘要 |
PURPOSE:To detect the overcurrent of a main output correctly, by detecting the load current of the main output indirectly as an overcurrent detecting signal. CONSTITUTION:A DC stabilized power source is provided with a primary side switching circuit 1, a main transformer 3, a rectification smoothing circuit 4 (main output), a rectification smoothing stabilizing circuit 5 (auxiliary output) and a stabilized control circuit 7 while the overcurrent detecting circuit of the same power source is formed by a primary current detecting circuit 2, the current detecting circuit 6 of the auxiliary output, a current correcting and comparing circuit 8 and a current detecting and comparing circuit 9. A power source input is supplied to the input terminal T1 and is delivered from a main output terminal T2 and an auxiliary output terminal T3 after stabilization. The current correcting and comparing circuit 8 operates the primary side switching circuit 1 to interrupt the power source input through the stabilized control circuit 7 when these detecting currents I1, I2 have exceeded a preset value of current. Further, the rectification smoothing stabilization circuit 5 is operated when the current 12 has exceeded the set value, whereby the power source output (auxiliary output) may be interrupted.
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