Found in a 1970 EEE, this circuit can be applied to TTL ports. The supply is 5 V and the frequency, which depends on the crystal, can be between 1 and 3 MHz.
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...