This circuit was found in an English documentation from the 90s. It uses a PLL CMOS 4046 and is powered by a 9 V battery. The sensors are two electrodes that must be held by the person.
This circuit is from American documentation from 1973. It can be used to indicate when the logic...
This circuit is from an old documentation. However, it can be mounted with modern equivalent...
This interesting circuit, found in an old American publication, measures alternating signals in a...