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Sir East Coast Toaster . . . . . . . .
Whhhhhoooooooooops . . . . . . looks like I addressed you with another posters name, last time around.
UNLESS your hand slips while taking a measurement . . . . .then you might fully fit those parameters along with your also being a VERIFIABLE "Toaster"
I have passed the addee of the Rowlett address on Main St. several times thru the years but had no knowledge of their endeavors, ACT, thus the need to even look over their way.
https://www.google.com/maps/@32.9024707,-96.5710061,3a,75y,151.91h,71.02t/data=!3m6!1e1!3m4!1sAtDyXtI7otYgp5fFQvs0Rw!2e0!7i13312!8i6656
Looks like, as of 2014, the big cheese is still driving his Baby "Rincon Con-tri-rintal" and the other employees must be parking at the back.
This unit could have been using two other "local" manufacturers, with Teccor /Littelfuse supplying the units Teccor power triacs, and located at nearby Irving, Texas and the PCB
could have come from SVtronics in nearby "Arlen Texas" . . . .home of Hank Hill , Peggy, Bobby and Lu Ann.
Looking at the fiberglass wire loomed thermal sensor, it looks more like a thermocouple *** wire " bead "instead of the smallest open thermistor die that I have ever seen .
*** (Good Lawds . . . . . be vewwy-vewwy carefuls . .a la E.Fuddster, . . . .as spel cheks done tellin' me that it 'posed to bees " thermonuclear " . . .shudder . . .shudder !
Now if it is a J or K type of thermocouple junction it should be having a low resistance reading, just for testing purposes of the bead junctions ohmmic integrity, as its ACTUAL manner of operation, is being its GENERATION of a varying DC output voltage , in accordance to the temperature being sensed.
See this reference, for relating to common wire resistances versus lengths.
http://www.conaxtechnologies.com/tech/newpdf/WireSize.pdf
In the up to 1 "tousand" degrees that this heater unit is capable of being subjected to, the thermocouple would be the preferred temp sensing medium, as compared to using a thermistor.
Also in the use of clip leads in your ohmmic testing, a hard oxide, relating to the heating in the creation of its end bead, may not let a confirmed connection be established with your clips.
Unplug the unit at the controller board and make measurement at those terminals, to see if a low ~2-5 ohms resistance is found. If not, then clip ohmmeter to one connectors lead and test at its end
connection to the thermal bead by additionally scraping the wire to get a clean bare connection exposed.Then do its other lead to the bead.
If reading open circuit, that's an oddity, since those units are usually quite hardy, unless mechanically abused.
Pass me the Teccor Triacs part numbers so I can ascertain thie specs and see if other than the tack soldering in of a 220 ohm resistor from Heater Triacs MT1 terminal to its gate would be needed.
That would "switch" on your heater element IF the power relay is turned on by its relay driver transistor.
Also confirm, if ~9 VDC is present on that transistors collector, if so, the other switching aspect of the heating element could be tested by shorting that tansistors C-E to turn on the relay,
along with the Triac already being shunted, should make the heater element active. Then you pull both "test aids" and back track to see if there is base drive coming to the relay driver transistor OR if any
combination of knob and switch kerblitzing causes the relay drivers transistors base drive to come forth.
If the thermocouple proves to be open, the subbing in of a 2 ohm resistor across its plug in at the controller, might make the unit operable, for a further " test aid" / evaluation but without viable temp control.
BTW does the stirrer motor activate ?
Also, over near the corner of the power PCB , I thought that there was a small bat handle switch there, but it's labelled as J2. So my guess is that the JACK is for an optional long leaded rod sensor
to dip into the heated Pyrex beaker for additional temp sampling.
Your photo clips off part of the plug in to J2.
I think that there might be a stubby plug in, present now, that has a mini temp sensor on its end, that is just measuring room temperature, considering that one is not using the extended probe plugged into that jack.
Thaassssit for now . . . . . .
73's de Edd
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