dead transformer on ceramic oven

[Wolf1977]

hi in ceramic oven the transformer is damaged
and writes
2x115v/2x12v/6VA 50-60hz ta105/f
can you suggest me a compatible transformer ;
i have found in 70 degrees celsius do you think is suitable for ceramic oven ;

[stj]

Re: dead transformer on ceramic oven

got any pictures?

how is it wired, is the 115v windings in series for 230v?

[Th3_uN1Qu3]

Re: dead transformer on ceramic oven

His location says Greece so it's most likely 230V.

[Wolf1977]

Re: dead transformer on ceramic oven

yes right
is connected in series 230 volt power supply and the output has 2 x 12 volt ac
and hat to connected 0 of first coil connected to 12volt to second coil and to ac pin of bridge rectifier
and the 12 volt of the first coil connected to 0 volt of secondary coil and goes to the other ac pin of bridge rectifier and eac coil must be 3va 250 ma fuse
so accordingly the above connection the bridge has 24 v ac input ; i ask because i am thinking to test the pcb with an external power supplu just to be sure
but the temperature enviroment is 105 degree celsius because writes 105ta/f
all the transformers i have found until now is ta 70 degrees
furthermore the transforer is solder on pcb so i have to find a transformer with the same pins to solder on the pcb
the device is ceramic oven

[Th3_uN1Qu3]

Re: dead transformer on ceramic oven

105/70C is the temperature the thermal fuse inside the transformer burns at. I doubt the PCB reaches anywhere near 70C as there must be some capacitors on it as well. I would say go ahead with the transformer with 70C fuse If all other parmeters match.

[Wolf1977]

Re: dead transformer on ceramic oven

and why the specific transformer sir writes ta105/f
and all the other that i can find from datasheets writes ta70;

[Wolf1977]

Re: dead transformer on ceramic oven

ok sir thanks a lot for you said thats right
this transformer is comatible on your opinion if the pins fits of cource
something last
if i canoot find transformer with the same pins can i solder on pcb with special
wire for temperature ;

[stj]

Re: dead transformer on ceramic oven

try looking at TME website

[R_J]

Re: dead transformer on ceramic oven

and why the specific transformer sir writes ta105/f
and all the other that i can find from datasheets writes ta70;

This transformer is ta105/F Fahrenheit which would be 40C (many have this 40c rating)
The HAHN transformer is ta70/C/B Celsius maximum ambient temperature 70°C, thermal class of insulation B (130°C)
If the pins match it should be ok.
There are many suppliers of this type of transformer from different manufacturers

[Wolf1977]

Re: dead transformer on ceramic oven

thanks a lot sir
so in your opinion its better to choose transformer with temperature
ta 40 degrees as the original or 70 degrees like this on the foto ?

[redwire]

Re: dead transformer on ceramic oven

What make/model is the oven?
The temperature spec is "maximum ambient temperature ta" in IEC 61558 but I think lower with an internal thermal cutout. I don't see a fuse for it on OP's board pic.

[Wolf1977]

Re: dead transformer on ceramic oven

siemens
so sir what do you suggest me ta 40 celsius or 70 celsius
if i found compatible pins with the old of cource

[R_J]

Re: dead transformer on ceramic oven

The original transformer was rated 40C, and that should be all that is required, but if you want to install a 70C that will be fine as well, I doubt the area for the power supply gets that hot.

[Wolf1977]

Re: dead transformer on ceramic oven

thanks a lot sir finaly i look for transformer with ta 40 celsius like the original and not for 70 celsius
because i am thinking if something go wrong as about as the temperature to break the thermal fuse of the transformer to be sure for the worst case e.g fire

[Wolf1977]

Re: dead transformer on ceramic oven

something last
in this foto it seems an other transformer for ceramic oven
why writes ta105°C/f
thats mean 105 degrees celsius or farenhait like my case ;
thanks a lot for your patience just i do a lot of questions to be sure for my choice

[Th3_uN1Qu3]

Re: dead transformer on ceramic oven

It's always Celsius, there are no parts rated in Fahrenheit degrees, it's a convention respected all over the world.

[R_J]

Re: dead transformer on ceramic oven

I made a error, It is 105 Celsius and the /F is likely the insulating material class F=155 Celcius

I see similar transformers rated ambient temperature 40c, insulation class 105c

It may be a special production as most of the Avisor transformers seem to be rated Ta70

[Wolf1977]

Re: dead transformer on ceramic oven

thanks a lot sir
so its a special edition of transformer that is used in this device
if i use ta 70 class b probably i will have problem
it seems in the internal of ceramic oven the temperature is bigger from 70 degrees celsius so probably breaks the thermal fuse that is 70 while on the original was 105
do you agree with this ;

[redwire]

Re: dead transformer on ceramic oven

Does the oven heat up the transformer? You know, when cooking moussaka.
What model oven? It's the extra heat the control board sees when baking for a long time.

[Wolf1977]

Re: dead transformer on ceramic oven

The ceramic hob is independent of the oven, it gets a separate power supply, but it is mounted on top, nevertheless I do not know how much it is affected