This power step drains just 3.5 mA from the battery and can provide good playback on a 4-ohm speaker. The circuit is from an 80's documentation.
We found this TTL circuit with the 7400 in the January 1975 Radio Electronics magazine. The power...
This adjustable direct current source circuit uses a triac operating as a variac. The circuit is...
This radio's transistor is powered with the signal's own energy, producing its amplification....