This is a different circuit for a component from the past, the zirconium arc lamp used in projectors. The circuit is from an August 1972 Radio Electronics magazine.
This circuit is from the National Semiconductor Audio Handbook. The amplifier operates with 6 V...
This switched filter was found in the 1969 documentation. The FET should be current-matched and eventually...
This independently charged circuit was found in a 1969 EEE. The operational amplifier supports a...