Using two unijunction transistors, this circuit found in Electronics World generates linear sawtooth signals. The frequency depends on the capacitors being around 500 Hz.
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...