This circuit with two transistors was found in ancient European documentation. Transistors support equivalents. The indicator on this circuit is an ordinary 50 to 100 mA lamp.
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...