The operational amplifier used is not common today, but the circuit can be implemented with modern operational ones. The gain is 1000 and the source must be symmetrical.
This circuit was found in February 1976, Radio Electronics magazine. The circuit is powered by 12 V...
This circuit was obtained in a 1973 publication, being implemented with TTL technology. The...
Found in a 1969 documentation on neon lamps, it actually takes advantage of the durability of the neon...