| 摘要 |
PURPOSE:To stably drive by a sole power source by providing a series circuit of a diode and a capacitor between the source and the drain of an MOS FET connected between a DC power source and a load, and driving the gate by a transistor provided separately. CONSTITUTION:A control circuit 50 which has an MOS FET Q1, transistors (TR) Q2, C1, resistor R and D1 is connected between a DC power source VB1 and a load 60 which has a resistor RL, a capacitor C2, a coil L and a diode D2. In the circuit 50, C1 is connected between the emitter 14 of the TR Q2 and the source 10 of the FET Q1, and D1 is connected between the emitter 14 and the source 12. The resistor R is connected between the gate 18 and the source 10. A control pulse 22 of the prescribed repetition frequency is inputted to the base 20 of the TR Q2, and stable and highly efficient MOS FET power source circuit can be formed by varying the pulse width of the pulse 22 in response to the state of a load 60. |
