Gain 10 Voltage Amplifier (T456E)

This 4-stage circuit has a voltage gain of 10 and negative feedback. The circuit was found in an old MIT publication.

Ladder Generator (CB21245E)
Using a 4017 as a base, this circuit from a 1990s Popular Electronics generates low-frequency...
Proximity Relay 741 (CB11585E)
Approaching the hand or an object to the sensor of this circuit, the relay closes its contacts. The...
Old Integrated Amplifier (CB6159E)
This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an...