We found this circuit in a 1967 American documentation. It is a transmitter for animal research, monitoring intestinal pressure. The operating frequency is 22 kHz.
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...