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 circuit for vehicular use is from an 80's American publication. The circuit has a light...
Texas Instruments TMP116 and TMP116N digital temperature sensors can be obtained from Mouser...
This circuit is used to detect PLL signals from the 4046 IC. The circuit is from an Electronics Now from...