A regulated power supply provides a regulated supply voltage at a preselected level under normal operating conditions. When power demands of the circuitry driven by the supply requires a higher voltage, the supply adapts to supply such a higher voltage. Such a supply can be used with automotive electronic circuitry, and can supply voltages up to approximately the voltage available on an automobile battery when such higher power demands occur. The higher supply voltages remain regulated, and return to normal levels when the extra power requirement is removed.