This simple power supply, which is equivalent to 2 AAA or AA batteries, was found in an Elektor from the 90's. The transformer has a 4.5 V secondary with a current of 50 mA or more.
The circuit bellow shows how four inverters [NAND, NOR or Inverters] Kim - This could be NAND,...
This circuit came out in a 1978 American publication, but can be assembled with transistors BC547 or...
This is one of the many modulated siren versions that can be found on our website. We found it in a...