This circuit is from a March 1978 Radio Electronics magazine article that showed how to build it. The circuit is TTL based and is powered. The components used can still be found.
This programmable sound circuit was found in the July 1978 issue of Radio Electronics magazine. It uses an...
The circuit shown simulates a programmable unijunction transistor (PUT). Transistors may be common...
This simple test lets you measure zener voltage. The power must be higher than the diode tested...