This is a typical circuit of a PROM programmer from the 70s. It appeared in the magazine Radio Electronics in 1979. Note that the programming was done manually byte by byte using switches.
This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a...
Found in an old English publication and in other parts of this website in different versions, this...
This circuit can keep a set of lamps on for up to 1 minute, time given by C2 and R2 that can be...