Abstract: A portable, self-contained and compact load bank of wire wound resistors utilizes wire wound resistors which are air cooled by a fan mounted in a venturi wherein the load resistors may dissipate power at up to six times their power rating. Current flow through the resistors is controlled by a transistor bank and portions of the resistors may be shorted out through taps connected to SCR's, with both the SCR's and the transistors being controlled by a microprocessor. The load bank is fully automatic, and because of highly effective air cooling, minimization of air flow resistance and use of edge wound resistors, the load bank is highly portable due both to its compact size enabling travel through normal passageways and its reduced weight. Both the microcontroller circuitry and the resistive load dissipation circuitry are contained within the same unit and are electrically isolated from each other by optical isolators.