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.
The National Semiconductor LM675 operational amplifier can provide up to 3 A of output current. In the...
We found this circuit in a 1969 Mullard documentation. The same configuration appears elsewhere in...
Found in a PE Hobbyst Handbook of 1991, this circuit was originally proposed to time photographic...