Found in the 1969 neon lamp documentation, using neon lamps this circuit provides 18 V regulated with 0 to 4 mA current. The lamps are types of the time.
This circuit is from a Japanese publication in 1967. The circuit uses a Geiger-Muller valve and...
Motorola's LM13600 integrated circuit is not very common today. The input voltage is 10 mV. We...
This circuit is from a 70s linear integrated manual. The integrated circuit used is uncommon today...