Temperature indication by effect on plastic part labels?
 

Valve amp with the three main lumps made by the same manufacturer and the
same sort of 0.05 mm soft white plastic part labels on the outside , so PVC
or polythene perhaps.
Output Tx label as original , choke just starting to show signs of
ruckling/cockling, and the mains transformer noticably ruckled , still same
white and footprint is the same ie the edges are in the original position.
So mains Tx has got the hottest presumably, any guesses as to what sort of
temperatures, and what if the label was seriously ruckled with distorted or
unreadable script or discoloured and shrunken footprint ?


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

Temperature indication by effect on plastic part labels?
 

"N_Cook" wrote in message
...
Valve amp with the three main lumps made by the same manufacturer and the
same sort of 0.05 mm soft white plastic part labels on the outside , so
PVC
or polythene perhaps.
Output Tx label as original , choke just starting to show signs of
ruckling/cockling, and the mains transformer noticably ruckled , still
same
white and footprint is the same ie the edges are in the original
position.
So mains Tx has got the hottest presumably, any guesses as to what sort of
temperatures, and what if the label was seriously ruckled with distorted
or
unreadable script or discoloured and shrunken footprint ?


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



In my experience, the temperature has only reached something to worry about,
when the wound components are actually smoking in use ... !!

Over a period of around 40 years that I've been repairing valve amplifiers,
I have seen many many examples of mains and output transformers, and HT
filter chokes, which have run so hot in normal use, that there is a large
pool of melted and resolidified wax around their bases.

Arfa

Temperature indication by effect on plastic part labels?
 

Arfa Daily wrote:
"N_Cook" wrote in message
...
Valve amp with the three main lumps made by the same manufacturer and the
same sort of 0.05 mm soft white plastic part labels on the outside , so
PVC
or polythene perhaps.
Output Tx label as original , choke just starting to show signs of
ruckling/cockling, and the mains transformer noticably ruckled , still
same
white and footprint is the same ie the edges are in the original
position.
So mains Tx has got the hottest presumably, any guesses as to what sort of
temperatures, and what if the label was seriously ruckled with distorted
or
unreadable script or discoloured and shrunken footprint ?


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



In my experience, the temperature has only reached something to worry about,
when the wound components are actually smoking in use ... !!

Over a period of around 40 years that I've been repairing valve amplifiers,
I have seen many many examples of mains and output transformers, and HT
filter chokes, which have run so hot in normal use, that there is a large
pool of melted and resolidified wax around their bases.

That's solidified magic smoke?

Temperature indication by effect on plastic part labels?
 

From trying to find thermochromic materials, this is some data I got along
the way, from trying Mylar film (or metalised plastic anyway) ;
bubbles/wrinkles 75 deg C, shrinks 80 degree C and shrunk to 1/4 95 deg C so
pvc and polythene probably similar


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