Abstract: A DC power controller for controlling the rate at which direct current is furnished to a load. A signal generator provides a periodic signal having a first value during a first portion of each period and a second value during a second portion of the period. A switch such as a power MOSFET enables direct current from the source to flow through the load during the time the signal has one of said values and prevents the current from flowing during the time the signal has the other value. A control is manually operable to vary the relative durations of the first and second portions of each period and thereby control the rate at which electric power is furnished to the load. A plurality of MOSFETS may be arranged in parallel if the load draws more current than one MOSFET can safely switch. Surge and back EMF protection are provided for inductive or variable resistance loads.