| 摘要 |
PURPOSE:To provide a driving circuit where useless current consumption is suppressed and a driving current is increased and also various kinds of switching circuits using the driving circuit by newly providing the circuit as a current limiting means. CONSTITUTION:When a transistor 3 is turned on, a DC power source 1 charges a capacitor 10 with a diode 5, the forward voltage of the diode 5 is applied to the transistor 4 as the reverse bias voltage and the transistor 4 is off-controlled. When the transistor 4 is off-controlled, only a resistor 13 permits the current to flow. When the transistor 3 is off-controlled, the current in the resistor 13 is almost enlarged by the magnification of the current amplification rate by the transistor 4. The synthesized resistance value is almost the value obtained by dividing the value of the resistor 13 by the current amplification rate. Therefore, the current is permitted to flow in the circuit consisting of the diode 5, the transistor 4 and the resistor 13, which is generated as the current limiting means, more easily when the transistor 3 is off than when it is on. |
