A solid state clock for an automobile or the like, which includes display means in the form of a vacuum fluorescent display. Current is supplied from the automobile battery to the display through an integrated circuit or "chip". The voltage from the battery is doubled by an inductor coil coupled between the battery and the integrated circuit. An electrical switching means in the form of a transistor is coupled between the integrated circuit and the inductor coil for supplying converted frequency thereto. A second switching transistor and a Zener diode is provided to regulate the duty cycle of the first transistor to maintain the voltage to the display substantially constant.
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.
