High impedance buffer (CB9557E)

This circuit was obtained in a 90’s American documentation. The FET can be replaced by a modern equivalent as well as the bipolar.

Freezing Sensor (CB6048E)
This circuit was obtained from an 80's Electronic Engineering. The circuit detects ice formation...
Multi-Feedback Band Pass Filter (CB4025E)
This circuit is from the Motorola Linear Databook published in 1990. The circuit for 1 kHz can be...
Alarms Using SCRs (CB455)
In the fist circuit the alarm triggers on when any sensor is CUT. In the second circuit the alarm...