This circuit was found in an Australian publication from 1991. It is a transmitter that transmits a signal when it detects moisture. The range is on the order of a few tens of meters.
This circuit is from 1990 documentation. It can be implemented with BC548 transistors instead of...
When you speak into the microphone of this circuit, the sound produced in the speaker resembles a robot...
This circuit uses an operational amplifier that is no longer on the market but can be implemented with a...