Phase Detector 7400 (CB22427E)

This circuit detects the phase of a signal. As it is a TTL circuit, it must be powered by a voltage of 5 V.

Relay Drive AC Stage (CB12182E)
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
Visually Impaired Electronic Guide (CB18123E)
With this circuit the visually impaired can easily locate important places inside the house, such...
Schmitt trigger (CB21475E)
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...