On Tuesday, 21 July 2020 16:08:56 UTC+1, Martin Brown wrote:
On 19/07/2020 23:52, Brian Reay wrote:

Before disposing of an old electric blanket, I looked inside the
controller. As you say, it was a simple switch to select the €˜elements.
It didnt have any obvious overheat detection in the controller.. There
could have been a simple thermal switch €˜buried in the blanket.

There is a fuseable link inside the little controller which blows if the
thing starts to draw unexpectedly high current or after about 5 years
whichever occurs sooner. They die much quicker if you use them on
maximum a lot the internal switch contacts are very cheap and cheerful.

The resistive load tends to fail open circuit eventually.

My 1950s one had none of that. I'm sure it'd have been safer if it had failed!


NT