We found this circuit in the 1982 SGS linear integrated circuit manual. The L149 is not common today and the circuit can be implemented with equivalents.
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...