Abstract: An inexpensive battery-powered switch or irrigation valve controller designed to conserve the life of both the low voltage battery source which operates the processing circuitry of the controller, as well as the high voltage battery source which operates the external switches or irrigation valve solenoids. The high voltage battery source is conserved by maintaining the primary switch-activating capacitor in a discharged state and delaying the charging of this capacitor until just before it is to be discharged. The high voltage battery source is also conserved by isolating it from the primary capacitor immediately prior to discharge, thereby avoiding a draw of energy from the high voltage battery source itself during discharge. The low voltage battery source is conserved through the action of the microprocessor that remains dormant except for periodic sampling. The controller also includes reliable DC circuits for operating remote switches or valve solenoids at distances of up to several miles.