This 1 kHz circuit was found in American documentation from the 90s. The original operational amplifier consists of a double 741 at the time. The power supply must be symmetrical.
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...