AC voltage control (CB8904E)

This circuit was found in a 90s Hands On Electronics. The semiconductor component is a Triac of the time.

Perforated card reader (CB8261E)
Found in a 1967 Ferranti documentation, this circuit uses a LDR from that time as a sensor....
10 kHz Salen Key Filter (CB5193E)
This low-pass filter was found in an American publication from the 80's. The circuit uses an...
Who is the fastest (CB4883E)
Who is the fastest? This circuit with neon lamp is powered directly by the network (there is no...