Found in a 90s Radio Electrconics, this circuit is an operational one with a power stage using two transistors. The output current can reach several amps.
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This stethoscope or amplifier for hearing aid using a crystal headset and microphone was found in a...
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...