The integrated circuit used is uncommon today. We found this configuration in Motorola's 1990 Linear Databook. The triac can be any of the TIC series.
We found this circuit in a Popular Electronics of the 90s. The MOSFET can be of any type,...
In fact, the correct name would be a hearing aid amplifier. However, we use the name of the...
This circuit controls a relay causing it to open and close its contacts at a speed that depends on the...