another oven transformer question/problem

[draylen19]

Hi, just found the forum and i'm a total beginner.

trying fo fix my oven..

here's the deal..got an error saying 12v is too low. and managed to find the source of the problem, this thing(pictures)

there 3 wires toward the control panel, i can get a read of 9.5v and 9.3v . so that should be the problem... since the board is expensive i'm trying to find the bad part and replace it.
the transformer say 12va parallel, was wondering how to exactly test it.
I managed to find the 4 connecteds pins on the output side of the transformer and got reading of around 6.5v ac on each pair. was wondering if i should get 12v each or combined they should be 12v.
input is fine. getting 120v from the L2.

if transformer seem fine i'll try to dig the other components

thanks in advance.

 

[Martaine2005]

Hi draylen19, looks like the transformer is 12VA, 6V+6V.
It may have 2 primary inputs of 120V+120V.
You can (or it is) Primaries in parallel for 120V or in series for 240V. Also 2 Secondaries as two 6V in parallel or 12V in series.

Martin

 

[Bluejets]

Says 12VA paralel.....show the other side of the board will be more helpful.
Unusual for tranny output to go low.

 

[draylen19]

sorry for the delay, got few problems :
yeah i got 2 pins with a 120v reading.
so if my "around 6v" are fine on the transfo. the low output could be another component.

 

[73's de Edd]

Really . . .REALLY . . .REALLY . . .ALSO need to see the brand and model involved.

 

[WHONOES]

Is the 12V meant to be ac or dc. It matters.

 

[draylen19]

frigidaire : cpcs3085LFA , part number : 316435703
I couldn't find the exact info for the output...but my 9.ish reading were in dc..and thats the only part that seems to match my error code.

 

[WHONOES]

Try removing the load from the power supply and then measure again. If the supply is rectified and smoothed, as it appears to be, then you should get 12 x 1.4 which = 16.8V. This does not take account of transformer regulation so it could be a fair bit higher possibly as much 10% or so.
Also, try measuring the output with your meter switched to ac and see what you get.

 

[draylen19]

With ac mode im getting 19,6v and 20v on the output.
and noob question, what does it to mean to remove the load ?

 

[WHONOES]

All transformers exhibit regulation. This may range from 1% to as much as 20% or more depending on the rating of the device. As an example, consider a transformer that is specified to 5% regulation. Its output voltage will vary by 5% from no load to full rated load so, a 20v transformer will give out 21v with no load applied and 20v with.
Removing the load from an unregulated transformer derived dc supply will cause the output voltage to rise. See my previous answer for why.
If you are measuring 19.6v on the dc output when you meter is in ac mode then, you probably have short circuit in one or both of the rectifier diodes.

 

[draylen19]

1 cable was not properply connected in the output toward the controlling board, with it being connected the output ac is 15v and dc show around 7v.
all diodes tested ok

 

[Bluejets]

What do you mean ac 15v and dc 7v.?
Where are you testing to...from....?
Or is that the same points?

What you have to remember here, is that while the test points may seem clear to you, everyone else has no idea as to just what you are testing in front of you.

Include some photos /drawings of what you are doing.
Plenty of online software to allow you to add arrows, notes, etc.