Dc-Dc Power Converter

54 DC-DC POWER CONVERTER T. Wigmore This high-efficiency step-up converter supplies up to 30 V at 75 W when powered from a 12 V car battery. The converter is ideal for many mobile and other out-of-doors applications: it functions as a power source for your DC-operated soldering iron, RF power amplifier, or NiCd battery charger for portable equipment such as a flasher or a video camera. DC-DC converters for stepping up the car battery voltage are generally based on a switched-mode power supply (SMPSU) or a power multivibrator driving a trans- former. The power converter described here is based on the first principle, and uses the Type TL497A integrated circuit from Texas Instruments. This device en- ables good voltage regulation with low output noise to be achieved fairly easily, and in addition guarantees a relatively high conversion efficiency. Design background The converter described is of the flyback type. The flyback principle is the only practical way of generating a direct ...