This high-impedance headphone circuit was found in a 1990s William Sheets. The power is low, but the high input impedance makes it useful for radio applications.
27 MHz Transmitter (CB14008E) This circuit was found in a Japanese publication from the 1970s. The...
This circuit, found in 2002 documentation, triggers LEDs when a phone call is received. The LEDs...
The R-S flip-flop shown here uses two NOR gates and is set and reset by positive pulses applied to...