摘要 |
<p>An electronic delay detonator for igniting an ignition resistor a predetermined delay time after supply of electric power from a blasting machine comprises two input terminals (10, 11) for receiving the electric power supplied from the blasting machine, a diode-bridge circuit (D,-D4) connected to the input terminals, a power supply capacitor (7) connected to the output of the diode-bridge circuit, an RC charging circuit (8, 9) connected in parallel with the capacitor and having a predetermined time constant, and a monolithic lC. The monolithic IC includes a reference generation circuit (5, 6) for generating a compare reference voltage by dividing the power supply by dividing resistors, a voltage comparator (2) for comparing the voltage charged in the capacitor of the charging circuit with the compare reference voltage, a signal latch circuit (3) for holding the output of the comparator and a transistor current switching circuit (4) responsive to the output of the signal latch circuit to for supplying the electric energy of the power supply capacitor to the ignition resistor of the detonator. The overall circuit is in a hybrid IC module. A resistor (32) having a constant resistance sufficiently distinguishable from an internal resistance of the detonator is connected across the two input terminals to bypass a stray current and enable checking of connection continuity of series-connected detonators.</p> |