[Gllug] Autodiallers with “Line Sensing

t.clarke tim at seacon.co.uk
Fri Jun 20 19:16:57 UTC 2008

Why not simply knock-up a simple transistor/relay circuit powered by a cheapo
6v or thereabouts mains adapter?

The 50V from the line across the gate of a BC109 or somesuch with a suitable
resistor in place will draw buggar-all curent from the line and so not affect
the autodialler.   I guess you might need some diode protection to stop
ringing current blowing up the transistor?

There are guys on the list who know far more about such things than I that
I feel sure could give you some hints on a suitable circuit - assuming you
can manage a soldering iron and get the the few bits required from the likes
of Maplin.

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