We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a BC558 and the common 6 V relay, just by using this voltage in the 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...