Found in old documentation, this circuit has only the most difficult component to obtain the PUT. The sensors are electrodes placed in the reservoir. The circuit directly controls an AC power load.
Found in an old publication, this is a transmitter with a spark coil. The high frequency...
This circuit was found in a 90s Hands-On Electronics. When a signal appears at the headphone...
In the figure we give a suggestion of a high-power stage to excite a speaker with the 2N3055. The...