Geo wrote in message
...
On Mon, 10 Oct 2011 08:48:23 +0100, "N_Cook"
wrote:

I have one in front of me labelled
UTM 210-9 25435,3 watt probably Russian and can find no info
Like the standard pillar white/grey ceramic resistors but instead of the
wire returning down the flute of the ceramic there is a sprung join set
in
the flute with bismuth solder or something. Anyone know a generic name
for
this type of thermal cut out resistor or a maker name ?
Other than the opening temperature must be greater than the sustained
power
rating temp of the resistor and lower than standard solder, anyone know
what
sort of safety cut out temperature?


Used to be quite common in TV sets (fusible resistor).
Have a look at the top left diagram on page 4 of this which shows
mechanical drawing:-
http://www.vishay.com/docs/21008/kk.pdf

Geo


if page 41 and in thermally cutout view , sprung open, then yes that type.
I'll have another look tomorrow in that pdf but I could not see the melt
temperature.

Only approximate this. Some flux over the join of this one in front of me
and then using the temp read function of my soldering iron before switching
off before reaching set point. Approx 130 deg C no cutout , 160 deg cuts out