We found this circuit in the October 1987 Radio Electronics magazine. The triac must be controlled according to the heater. The transformer has a low current, of the order of a few hundred mA.
We found this circuit in an old American documentation for hams. The circuit serves as a telegraph...
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This step uses germanium transistors such as the AC151, GE2, and others having been found in a...