Switched integrator (CB8871E)

Found in a1968’s Burr Brown documentation, this shield uses an integrated circuit from that time, which is uncommon today.

Metal Detector (CB18341E)
This interesting circuit was found in a 1967 Japanese documentation. Transistors are types of...
Simple anemometer (CB23571E)
This assembly circuit using a small motor as a generator was found in Radio Electroics magazine from...
Solar Battery Test (CB1355E )
This circuit is of great use today, when solar energy is becoming increasingly important. The...