This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a double-contact changeover relay. Sensitivity adjustment is made at R2.
This circuit was obtained in the National Semiconductor Linear Applications Handbook of 1994. The...
This circuit was found in a Hands-On Electronics. Some restrictions must be considered as the need...
This circuit was found in a 1987 magazine. It measures the resistance of the skin using a...