| 摘要 |
PURPOSE:To eliminate the need for a complicated sequence circuit and also to attain miniaturization and high reliability by allowing a logical integrated circuit to be operated normally at first by application of power to the circuit and turning on a large current drive element with a delay so as to drive an electromagnetic switch. CONSTITUTION:When power is applied to a power supply terminal 7, since the logical integrated circuit is operated normally at 3-3.5V, a circuit 1 is operated normally at first via a resistor 2. When a constant voltage diode 6 reaches a breakdown voltage or over, a drive current flows to a gate of the large current drive element 4 so as to turn on the element 4 and drive the electromagnetic switch 3. That is, until the circuit 1 reaches normal operation, the supply of drive current is blocked by the diode 6. In interrupting the power supply to the power supply terminal 7, the drive current flowing to the gate of the element 4 is stopped, the element 4 is turned off, the voltage applied to the circuit 1 is dropped after the electromagnetic switch 3 is opened and the circuit 1 becomes inoperative when the voltage becomes 3-3.5V or below. |
