| 摘要 |
PROBLEM TO BE SOLVED: To provide a full-bridge drive circuit which is small-sized, simple, and unexpensive, and does not need any special circuit component for driving switching elements. SOLUTION: Series-connected transistors Q1, Q3 and Q2, Q4 are connected in parallel, and diodes D1, D2 are connected between the transistors Q1, Q3 and between the transistors Q2, Q4 respectively. Both ends of the primary winding a1 of an output transistor T1 are connected between the transistor Q1 and the diode D1 and between the transistor Q2 and the diode D2 to form a bridge circuit. Along with it, a transistor drive circuit 10 for on/off controlling the transistors Q3, Q4 alternately is provided. Detecting current flowing in a resistor r1, the transistor Q1 is turned off when the transistor Q3 is turned on, and detecting current flowing in a resistor r2, the transistor Q2 is turned off when the transistor Q4 is turned on. |
