DIGITAL DELAY UNIT

An extended delay detonator (blasting cap) provides a preselected, electronically controlled delay between an incoming non-electric impulse input signal from, e.g., a shock tube or other input transmission line, and detonation of the output charge of the detonator. The delay detonator has a housing closed at one end and open at the other end for coupling to the input transmission line, the signal from which may be amplified by a booster charge mounted within the housing. A piezoelectric generator converts the optionally amplified impulse input signal to electrical output energy. A battery-powered programmable electric delay circuit is activated by the electrical output from the transducer, counts the preselected delay period, and at the end thereof ignites an electrically operable output charge. A method for interposing a preselected delay between the application of a non-electric impulse input signal and the detonation of the output charge is also provided.