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.
We found this circuit in an old documentation. The integrated circuits used are specific to...
The integrated circuit used in this application is uncommon today and specific to the application, as it...
This 3-transistor buzzer or buzzer is a classic type found in the July 1998 issue of Electronics Now...