Telephone Line Simulator (CB25592E)

This circuit was found in the August 1993 Electronics Now magazine. It is for telephones used on common old-style analog lines.

| Clique na imagem para ampliar |

Ambient light indicator (CB21567E)
This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The...
Light Controlled Tone Generator (CB18637E)
We found this circuit in an American publication from the 80's translated into Portuguese. The...
Perforated Tape Reader (CB16920E)
We found this circuit in an old French documentation from the 70s, but it can be assembled using...