Driver for oscillograph (T459E)

This circuit from an old MIT documentation excites an oscillograph element, an old waveform viewer.

Automatic Battery Charger (CB10565E)
This circuit is from a 1987 magazine, but it can still be easily assembled, as the components are...
Bargraph Humidity Indicator (CB11519E)
This circuit was found in a Popular Electronics from 1991. The transistor could be the BC548. The...
Capacitive Differential Meter (CB9493E)
This circuit, which can be used to indicate the movement of an object, was found in NASA...