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.
Found in an Elektor from the 90s, this circuit is based on components that are still common today....
This circuit was found in a Signetics documentation from the 1980s. Next to the figure are the...
This timer of 10, 25, 45 seconds and 5 minutes has its times selected by the keys. The circuit drives...