The circuit presented is a documentation for radio amateurs from 1978. Implemented with common CMOS and linear components, it indicates CMOS logic levels.
This circuit was originally recommended to operate with the emitter of the previous circuit but...
When the probes of this circuit meet water, the relay closes its contacts. The circuit is from a May...
The power supply shown can supply voltages of approximately 0 V to 12 V with a maximum current of 4.5 A,...