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 was found in an old Poptronics but is still current as transistors can be replaced...
This circuit generates a multiple Inal with 3 outputs and whose frequency depends on the values of the...
We found this circuit in a documentation on active filters from 1977. The gain of this circuit is...