| 摘要 |
PURPOSE:To simplify a DC/DC converter circuit by adding a coil to an oscillation transformer, opening or shortcircuiting the circuit of the coil to turn ON or OFF the oscillation of the converter, thereby effectively operating it without error. CONSTITUTION:When a switch SW is opened, the impedance of a transistor Q5 exhibits the value near infinity, an oscillation is started by the starting operation of a closed circuit of a coil N1, a capacitor C3 and a transistor Q4, and the oscillation is maintained by the feedback of a voltage by the coil N1 and the feedback of a current by the coil N4. Since the impedance of the transistor Q5 becomes very small value when a switch SW is closed, the coil N4 of an oscillation transformer T2 is shortcircuited via an extremely small impedance. In this manner, the drive of the oscillation transistors Q1, Q2 of the converter is stopped, and the voltage between the output terminals 3 and 4 of the converter becomes zero. |
