This variable frequency circuit was found in a Popular Electronics from the 90s. The circuit outputs to a small speaker and can be powered by voltages as low as 3 V.
In this circuit found in a Texas Instruments 2016 documentation we have an adjustment for the...
This circuit is ideal for creating a source that allows the use of automotive power devices on a...
This circuit is from an English publication of 1982. The bipolar transistor can be a BC548 and the...