This 100 second timer was found in the September 1992 issue of Radio Electronics magazine. The circuit has two timing ranges and time adjustment at R6.
In this circuit of the 1980s, the T1 transformer has 30 turns of 28 primary wire and the secondary...
The circuit presented was found in a Japanese magazine in 1973. The circuit uses transistors of...
This circuit uses a parallel resonant crystal to control the frequency. The circuit is from Radio...