This shield circuit is from an American documentation from 1969. The components can be modified according to the relay and power, and the coupler can be of a modern type.
This circuit was found in Philips documentation from 1965. No information was given about the...
This sophisticated decade of benchtop resistors was found in the November 1989 issue of Radio...
This configuration based on a conventional astable multivibrator was found in a 1982 publication. The...