ELECTRONIC SLOW-WAVE CIRCUIT AND DELAY CIRCUITS Russian patent published in 2003 - IPC

FIELD: blasting operations; electronic-delay detonators including programmable ones with electronic slow-wave initiation. SUBSTANCE: electronic slow-wave circuit used for initiating delay detonators has generator, programmable timer circuit, and operation control circuit. Generator produces clock signal that depends on rate of capacitor discharge relative to reference voltage REF. Second capacitor is charged up to voltage exceeding REF and when voltage across first capacitor drops below REF value, internal signal is generated and capacitors are changed over so that first capacitor starts charging while second one is discharged. Clamper generates clock-frequency pulses in response to internal signals. Programmable timer circuit has wave counter and programming group that functions to enter counted values in counter during initiation. Each stage of counter has separate inputs for 0 and 1 setting signals. Programming group has 1 setting circuit and 0 setting circuit for each counter stage. Each 0 setting circuit generates fixed- length signal and each 1 setting circuit can produce signal having two different lengths, one of them exceeding 0 setting signal. During programming short or long 1 setting signal is produced in the course of counter loading Length of 1 setting signal or of 0 setting signal shows state of counter stage. Operation control circuit controls logic gate that enables generator pulses to increase counting rate of counter but it cuts off logic gate in case of temporary supply voltage failure thereby preventing timer re-initiation. EFFECT: enhanced operating reliability of detonators. 12 cl, 13 dwg