Using LM3909 integrated circuits, this circuit was found in an American documentation from the 90's. The frequencies can be changed by changing the capacitors.
This circuit causes an LED to blink from the 1.5 V supply thanks to the use of a voltage doubler. The...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
This temperature control was found in General Electric documentation from the 90's. The circuit uses...