This circuit implements two logic functions at the same time. The diodes are for general use and the resistors have typical values of 2k2 for logic of 5 V.
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...