Abstract: A power supply for a large or dual vacuum fluorescent display having a DC source coupled to a switching regulator to generate a stepped up DC voltage. A -5 volt regulator is coupled to the switching regulator output, to provide a second DC voltage. A grid and segment driver is supplied with the regulator output. The driver is coupled to a microprocessor, and selectively drives the grid and plate segments to display data from the microprocessor. An oscillator circuit is also coupled to the DC source to generate an AC signal. The AC signal is coupled to an inverter to generate a second phase-shifted AC signal. The AC signals are provided to a pair of output drivers which amplify and output each signal to opposite ends of the filaments to heat the display filaments.