This mains-synchronized circuit produces a simple 1 pulse per second. The circuit is from a Radio Electronics magazine from May 1977.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This LED signaling circuit uses a programmable unijunction transistor (PUT) as a relaxation...
This is a commercial circuit from a Japanese publication from 1972. The circuit uses a FET that...