This circuit can activate a powerful lamp or call system when a telephone call occurs. Suitable for hearing impaired or noisy places it was found in American documentation in the 90s.
We found this circuit in a 1967 Electronics World. It analyzes a transistor by determining its...
This circuit monitors the output level of an amplifier. The circuit is set to R4 and can be...
Originally designed for an incandescent lamp, this flasher or pulser can be adapted to operate with...