This timer was found in Japanese documentation from the 1960s. The transistor can be replaced by an equivalent and the relay must be of the sensitive type with voltage according to the power supply.
Suggested for use in cars and motorcycles, this circuit was found in a 90s Popular Electronics. The...
This is a typical 3 ½ digit TTL counter. We found it in the September 1973 issue of Radio...
This receiver, whose tuning range depends on L1 and L2, was found in the 1992 special edition of...