| 摘要 |
PURPOSE:To improve remarkably the detection sensitivity by detecting directly a fault such as layer short-circuit of a high voltage coil of a flyback transformer from the voltage of the high voltage coil. CONSTITUTION:Resistors 14, VRF, VRS, 15 are formed by printing a pattern on a board 17 such as focus pack by the method of baking and the other terminal of a detection resistor 15 is connected to a reference potential. The lead 18 for extracting the detection voltage is connected to the detection resistor 15 and a detection voltage VD extracted by the said lead 18 is utilized to attain a desired safe operation. Thus, if a fault such as layer short-circuit takes lace in the high voltage coil 8, it is possible to detect the fluctuation (abnormality) of the high voltage output voltage EH with high sensitivity and the circuit safe operation is attained quickly and surely based on the result of detection. |
