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 VCO with a common operational amplifier was found in an old American documentation. The...
This circuit is from a Radio Electronics magazine from May 1989. The power supply must be...
August 2017 - Mouser Electronics is making STMicroelectronics' Analog and Digital MEMs available in a...