We found this circuit in an English publication from the 60's. The transistors are of germanium of the time and the headphones must be high impedance magnetic.
July 2017 - Texas Instruments' new 3 A bq25601 single cell battery charger can be found on Mouser...
This circuit was found in old documentation. PUTs are uncommon components today. The circuit...
This simple timer with unijunction transistor was found in an old American technical...