These optical relays, which can act as a shield, were found in an American documentation from the 1980s. The circuit has a LDR sensor. It can be adapted for other types of sensors.
I got this circuit from an English magazine from 1977. It can still be easily assembled, as the...
The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or...
This circuit controls a heating element using a triac. Triac must be fitted with a heat sink. We...