A method of detonating explosive charges for the breaking of rock and ore comprises the use of two sets of components, one set within the explosive charge and the other set at the surface of the explosive. The set within the exposive comprises a detonator, a first delay element and a passive energy storage device such as a capacitor. The second set which is able to communicate with the first comprises a power source, a second delay element and a means for receiving signals from a remote command source. In a preferred embodiment, the first delay element has a fixed delay and the second delay element has a programmable delay.The method permits of versatility and precision in the use of explosives, using relatively inexpensive components.