This circuit was found in a 1967 documentation. It is intended for triggering a xenon LASER. Observe the high operating voltages of the circuit. The components used are uncommon today.
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...