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.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...