This circuit from an old documentation uses an optocoupler to control the feedback. FET is difficult to obtain today, and modern types can be tried. The power can be increased if LEDs with appropriate current limiting resistors are used.
This circuit from an old documentation uses an optocoupler to control the feedback. FET is difficult to obtain today, and modern types can be tried. The power can be increased if LEDs with appropriate current limiting resistors are used.