This circuit was found in an Electronics World of 1968. Its purpose in triggering a relay when the circuit receives signals from a vibration sensor. The circuit is used in emergency situations.
Using an integrated circuit from the time, this circuit was found in Radio Electronics from the...
This shield circuit is from old documentation. The operational amplifier used is not common today...
This circuit powers a small 5 W lamp that goes out when power is lost. The circuit can use the...