This circuit was found in the December 1992 Radio Electronis magazine. R2 is an NTC, there is a MOV protector or NTC thermistor. The current depends on the thermistor used.
This simple timer can be used in many applications such as egg timer. The LED glows up when S1 is...
We find this circuit in a 1980s documentation. The circuit is for SSB modulation and the...
This circuit was found in an old American documentation aimed at amateurs. The circuit generates...