We have many versions of biofeedback with the 555 IC on this site. This is another one. We found it in October 1986 Radio Radio Electronics magazine. The power supply must be isolated.
This bank of switches can be programmed in a variety of ways for logic experiments. The circuit is from...
This circuit is from a 1968 publication. Here we have several types of resistive sensors with...
This circuit was found in a 90s Popular Electronics. Both the coupler and the MOSFET can be of any...