This circuit, with a 12 V input, was found in a Popular Electronics from the 1990s. Information is given about the ferrite-wrapped transformer. The transistor must be mounted on a heatsink.
We found this different configuration that uses a fluorescent lamp as a negative resistance device...
The integrated circuits used in this thermometer are not very common today. The indicator is a...
In the figure we have the way to control a triac of the TIC series with a low voltage through a...