| 摘要 |
PROBLEM TO BE SOLVED: To prevent a component of a gate control circuit A connected to a gate from being burned by applying a drain voltage of a switching element Q to the gate when the drain and the gate of the element Q of a primary side of a switching power source is damaged due to a short circuit. SOLUTION: A cathode of a constant-voltage diode D is connected to the gate of the switching element Q of a primary side of the switching power source, and an anode of the diode D is connected to a source of the element Q. Thus, even when the drain and the gate of the element Q are short circuited, a large current flows to the diode D at a moment when the high voltage of the drain side is applied to the gate so that the diode D is damaged with the result that the drain and the gate of the element Q are short circuited. Accordingly, a fuse F can be melted without burning the component of the control circuit A connected to the gate of the element Q burned. COPYRIGHT: (C)2003,JPO
|
