Found in an American documentation from the 90s, this circuit makes use of an output transformer for transistors, working with a 6 V power supply.
This transmitter for the 6-meter (50 MHz) radio-amateurs range was found in a publication from the...
This neon lamp level indicator circuit uses low voltage power supply. The circuit was found in a...
This fully passive circuit was found in documentation from the 1970s. The circuit uses an optical...