Telephone in use indicator (CB9467E)

We found this circuit in a Hands-On Electroncs from the 90s. The circuit uses an LED indicator. Diodes are general purpose types.

| Clique na imagem para ampliar |

Digital Volume Control with PIC (CB17627E)
This circuit is an excellent application for the PIC in audio, but the reader who intends to do...
10 W amplifier (CB9905E)
To a 16-0hm load, this amplifier provides a power of 10 W. We found this circuit in a Motorola...
TTL Output Magnetic Reader (CB14249E)
This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in...