Electronics > Beginners

Transformer question

<< < (3/6) > >>

Benta:

--- Quote from: ArthurDent on February 02, 2019, 09:34:26 pm ---Here is a handy reference to explain it all.
http://www.hammondmfg.com/pdf/5c007.pdf

--- End quote ---

That "handy reference" doesn't explain anything at all. Quite the opposite
Please explain to me why "FULL WAVE BRIDGE Resistive Load" tells me to multiply voltage and current by 0.90?
I don't even want to comment on the other configurations, that would be a total waste of time.

Apparently "Hammond Manufacturing" needs any excuse to derate their transformers, leading me to doubt their products.

Nusa:

--- Quote ---3. Secondary: Series: 24.0V CT@ 5.4A; Parallel: 12.0V @ 10.8A
--- End quote ---

The CT presumably stands for center-tap, so clearly they're perfectly fine with that configuration. That's what you want anyway, right?

soldar:

--- Quote from: Benta on February 02, 2019, 10:31:19 pm --- That "handy reference" doesn't explain anything at all. Quite the opposite
Please explain to me why "FULL WAVE BRIDGE Resistive Load" tells me to multiply voltage and current by 0.90?
--- End quote ---

VA or Amps are given but they are for a power factor of 1. If power factor is less then Amps should be reduced accordingly. Full bridge rectifiers have a very poor power factor. Thus the 0.90 reduction which I would probably reduce even more.

ArthurDent:
Benta – “That "handy reference" doesn't explain anything at all. Quite the opposite
Please explain to me why "FULL WAVE BRIDGE Resistive Load" tells me to multiply voltage and current by 0.90?
I don't even want to comment on the other configurations, that would be a total waste of time.”

So far you’ve questioned Triad and Hammond (who have been making transformers for ages) about their transformer application knowledge. Perhaps reading other explanations about reducing transformer ratings for use with different rectifier setups might help you understand. The ratios may vary depending on the transformer design used but the principles are the same. 
https://www.powervolt.com/how-to-determine-page-25
https://www.nutsvolts.com/questions-and-answers/transformer-ratings

basinstreetdesign:

--- Quote from: PinheadBE on February 02, 2019, 04:10:08 pm ---Hi,

I just bought a transformer whose datasheet ( https://www.mouser.be/datasheet/2/410/media-1067921.pdf ) states that:
"Primary and secondary windings are designed to be connected in series or parallel. Winding are not
intended to be used independently"

Does that mean that I may not use it to build a +12V/-12V where the currents in each winding would not be perfectly balanced ?
Why is that ?

Thanks

--- End quote ---

Wow.  Here I thought it was pretty obvious what the manufacturer was referring to.  I never thought a bunch of people like you guys could go off on so many tangents.

The only explanation for that quote that makes sense to me is that to obtain the rated maximum VA rating of the transformer one must use all of the windings.  In parallel or series as needed.  That trying to get that much power through the transformer by using only two windings and leaving the other unconnected would not work so well as the wire gauge would be inadequate for it.  Yes, I'm making an assumption here but it is the only way this makes sense.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod