Found in Popular Electronics from the 90s, this circuit generates signals in a frequency range set to R7 and basically determined by C1. Operational and equivalent transistors can be used.
This experimental drone circuit was published in a Radio Electronics magazine article from...
This circuit causes an LED to blink from the 1.5 V supply thanks to the use of a voltage doubler. The...
This circuit consists of a traditional version of dimmer with triac and was found in a 2000...