BUILD THE VOLTAGE MIRROR

摘要

Recently, I designed and prototyped a battery-powered piece of analog equipment to run off two nine volt batteries. After the prototype was finished, it was decided that the device needed to have the option of using a wall-mount power supply, as well as batteries. Wall-mount supplies with +9V and -9V outputs are not easy to find, but ones supplying 12 to 15 volts DC are readily available. Instead of redesigning the main printed circuit board (PCB), I decided to use a small add-on board that would fit inside the enclosure. On the board would be an LM317 regulator to bring the supply voltage down to nine volts. Also on the board would be a TC962 charge-pump DC-to-DC converter.