| 摘要 |
PURPOSE:To improve the utilizing efficiency of power supply by providing additionally a constant voltage circuit keeping a part of voltage of a focus circuit in constant in a deflection coil of a television camera. CONSTITUTION:When a power supply from a battery is applied between terminals 11 and 12 and a reference voltage is applied between terminals 10 and 13, a current flowing to a focus coil 1 flows so that a voltage generated across a resistor R1 is equal to a prescribed voltage determined by a current setting adjusting device 5 at all times. A DC/DC converter 6 detects a collector voltage of a transistor TR1, then a required voltage set at a voltage setting device 8 added by a voltage drop of the focus coil 1 is obtained from an output of the converter 6 at all times. Thus, when the operating voltage is dropped, the converter 6 is operated and the voltage of required minimum value is applied to the focus coil 1. |
