Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be implemented with equivalent modern components, including lower voltage supply.
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...