Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be implemented with equivalent modern components, including lower voltage supply.
We found this amplifier for automotive use in the Philips integrated circuit manual from 1990. The...
This interesting circuit records a few seconds of audio signals, reproducing them in a small...
Settings like this can be found at various points on this site. The trigger door can be a 4093...