| 摘要 |
A power factor improving circuit comprising a control circuit (20) for receiving an output voltage from a voltage detection terminal (a) and turning a switching element Q1 on/off based on the output voltage, detecting/holding means (23, 24) for detecting an abnormality upon occurrence thereof in the power factor improving circuit, stopping the switching element, holding the stopped state and outputting a holding signal, an abnormal operation signal outputting means (30) for outputting a voltage not lower than a specified level, as an abnormal operation signal, to the voltage detection terminal (a) based on the holding signal from the detecting/holding means (23, 24), and an abnormality signal detecting means (40) for detecting the voltage not lower than the specified level at the voltage detection terminal (a) based on the abnormal operation signal from the abnormal operation signal outputting means (30) and outputting an abnormality signal to a load circuit (10). |
