Found in a yoghurt maker whose heating element never turns off :
Black plastic, 23.3 x 6.7 x 3.6 mm with two wires (red and black) coming out of one end. Marked TI-30 70 S2.
Judging by the shape, it could be a thermocouple or an RTD. Does anyone know what it is ?
Thanks in advance !
-- It is difficult to get a man to understand something, when his salary depends upon his not understanding it. -- Upton Sinclair
looks like one of those compact bimetal dome switches, try heating wiht a hot air gun connected to DVM-R
Probably a thermostat, PEPI and Klixon are manufacturers of this form of thermal switch.
If it must be replaced, you may find that 'authorized' repair of the appliance is required. Stocking and numbering of appliance parts is deliberately made obscure, and covered by layers of (usually feigned) concern using words like "tamper", "unsafe", "unauthorized".
Curious that two of two would say it's a thermostat even though the wires are of different colours. Reportedly, the yoghurt maker never clicked.
DC voltage across the device is a steady 0.0 mV.
The resistance is all over the place. Constantly changing values centred around 1.4 k one moment, then around 105 ohms the next, then 60, then 75... Tried shining a filament lamp on the device to heat it. Turning the light on or off sometimes causes an instant 30% jump in the resistance. Hours of fun.
Whatever this is, it's probably defective.
Thanks.
-- It is difficult to get a man to understand something, when his salary depends upon his not understanding it. -- Upton Sinclair
so nothing to loose, hack into it to see what was in there, now pitted/corroded/spark-etched contacts perhaps. Welds do fail if it is a thermocouple. Is it connected to mains or some sort of off-line control circuit?
I expect to see that VDE compliance triangle on mains rated components only
You can't expect a device that switches mains voltage to be very consistent when measuring those eroded contacts with a multimeter. If the element is stuck on it's possibly been busy preventing a fire.
From s.e.c.:
-- It's an entire thermostat, made by Ka Wo in Dongguan China. temperature. It will switch a few amperes at mains potential directly. This looks more like an overtemperature cutoff device than a control device to me, but then I have no idea how a yoghurt maker works.
Gordon Bennett ! I'd like to have your web search skills !
Wouldn't a thermostat have more hysteresis than is good for the ferments ? Either they're counting on the thermal inertia of the water in the yoghurt to smooth the temperature variations or there is a sensor hidden somewhere in there that I can't see.
The person who's doing the repair is as puzzled as I am and has given up on it. The cost (time, money, effort) and the fire risk if he gets it wrong make buying a new yoghurt maker more attractive. So that's another one for the dump. :-/
Sorry for wasting your time. At least I've learned a few things. Thank you all.
-- It is difficult to get a man to understand something, when his salary depends upon his not understanding it. -- Upton Sinclair
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