This low frequency circuit was found in documentation from the 1980s. The values of R and C determine the frequency. Inverters can also be designed with logic gates.
This circuit activates a relay when the water reaches the sensors. The circuit is from a magazine...
The noise comes from the PN junction of a common silicon diode. Since no gain is given by the...
We have here an interesting audio preamplifier, which can be useful to those who are looking to...