| 摘要 |
PURPOSE:To correct the time of delay and operate a primer with a correct time accuracy, by a method wherein a priming circuit is provided with a voltage limiting element, such as a Zener diode, and the element is switched into the intercepting condition to generate a priming signal when a terminal voltage has become lower than a predetermined value. CONSTITUTION:When the supply of energy from a blaster 1 is finished and a voltage impressed between the input terminals P1, P2 of a priming circuit 3 becomes lower than the Zener voltage of a Zener diode 12, the Zener diode is brought into an intercepted condition. A transistor 21 is conducted, the resetting condition of counting operation is released and a counting circuit 5 counts a set value, then, an igniting signal is outputted to a switching circuit 7 and the accumulated energy of a capacitor 2 is discharged into a resistor 6 whereby a primer is detonated. When the Zener voltage is set at 2V, a time delay from a reference time may be reduced to 10mS or less even when a drifting electrostatic capacity is high. |
