This circuit can be used as an answering password system in a store, office, or other location. The circuit is from Intersil using components of the time. The circuit is from the 80's.
This circuit makes use of the Linear Technology LT1637. We find it in a 2005 manual. The circuit...
This old circuit uses na operational amplifier not easy to find in these days. But the circuit can be...
The circuit shown in the figure is indicated for alternative sources of energy, such as those...