"N Cook" wrote in message
...
Those usually 3-legged black blocks containing 2 PTC disc thermistors.
One of a few tens of ohms (cold) feeding to the coil and one of a few
hundred ohms (cold) connected between live and neutral , what is the
function of the one across the mains ?
As that one is separated from the other by 2 sets of spring clips, it
cannot
be there for indirectly heating the one feeding the coil for quick
completion.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/


Isn't the second one across the back side of the first, rather than directly
across the mains? Sort of a two thermistor series / shunt arrangement. I
seemed to recall from my long-ago theory days, that they were the inverse of
each other, and that the one that's across is initially high resistance, and
gets lower as it heats up, to shunt the degausing coils, mitigating their
effect, and keeping the series thermistor hot - and hence in the high
resistance condition - by continuing to draw just enough current through it
to do that. Could be wrong - it's been a long time ago - but it 'feels'
right, and seems to work, in my head at least ... !!

Mind you, I'm going back to when they were two (definitely) different
individual components. The series one was a granular grey, and the shunt was
a little smaller diameter and a little thicker, with a mainly blue (painted)
body, with a yellow stripe at the top. I've probably still got some
somewhere. But perhaps they've come up with some other way of doing it since
they've encapsulated the two elements together.

Arfa