Freezing sensor (CB21288E)

This circuit was found in a Popular Electronics from the 90's. The components are common. The potentiometer adjusts the circuit's trigger point.

| Clique na imagem para ampliar |

Infrared alarm (CB7238E)
Found in 1968 Mullard documentation, this circuit uses period components. The transistors are...
Voltage Multiplier (CB20184E)
In the figure we have a modified multiplier circuit that can operate with the sextuplicator with...
Low frequency converter (CB9336E)
This circuit converts signals from the 350 to 500 kHz band to the 4.36 to 4.5 MHz band, enabling...