Richard Prosser wrote on 30/11/2018 07:00:
> Just to hijack things slightly, regarding the 'Designed to Fail' aspect.
>=20
> We have had a number of  electric blankets over the years and they all se=
em
> to last about 3 years and then die. In all cases it has been the controll=
er
> that dies although the problem is presented as a blanket failure.=20

My experience too. The blanket (controller) longevity seems to be=20
related to the amount of usage.

> We swap the controllers  side-side and all is well again (I don't use min=
e,=20
> my wife uses her side only).=20

Yes, same here.

> Then next time we buy a replacement controller set. Except that after 5-6=
=20
> years replacement controllers are no longer available anywhere.

Replacement controllers are not exactly cheap and so we usually bite the=20
bullet and buy a new blanket for not much more.

> I've taken a number of the controllers apart but been unable to figure ou=
t
> the faulty  part. The more expensive ones appear to have 2 PICs or simila=
r
> in them, one driving the display. The cheaper units have just one. The
> firmware in the PICs appears to be protected against downloading &
> examination.=20

Ditto - though mine invariably contain a single, code-protected=20
PIC12F675 which gets removed and repurposed :)

> It's quite possible that there's a count-down timer involved
> in the firmware.

Which makes me wonder whether this is a safety feature for "made in=20
China" quality blankets...
--=20
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