parallel resistance and transformers

Discussion in 'General Electronics Chat' started by wes, Apr 12, 2008.

1. wes Thread Starter Active Member

Aug 24, 2007
242
2
hey is it possible to connect a transformers secondary in parallel with some resistors so that the current would be higher on the secondary and the primarys current would increase to so that no laws are broken but your transformer can supply more power without increasing the voltage because the total resistance is now lower.

i dont have any numbers, this is just a hypothetical question

thx for any help

2. beenthere Retired Moderator

Apr 20, 2004
15,815
282
No. Transformers have a limit for the amount of power they can handle. Causing one to supply an overcurrent will just give you a hot transformer. It's the magnetic flux in the transformer core that moves the energy. Resistance has nothing to do with it.

Here is a link to our Ebook that explains how transformers work - http://www.allaboutcircuits.com/vol_2/chpt_9/1.html.

3. Externet AAC Fanatic!

Nov 29, 2005
761
57
Hello wes.
If your words "parallel resistance and transformers" can be interchanged with "parallel resistance and parallel transformers" ;

Transformer secondaries can be connected in parallel IF they are the same voltage, AND if the phases match.

A dual equal secondary transformer (not a center tapped) can have both secondaries paralleled in proper phase and their current capability will be summed.

That means the load resistance can be halved as in two equal resistors in parallel, and the transformer will be delivering twice the power if it is capable of doing it.

-If that is the core of your question-

Miguel

4. thingmaker3 Retired Moderator

May 16, 2005
5,072
6
The core of the question is the core of the transformer... The amount of power a power transformer can handle is largely determined by the cross section area of the core. The flux density explained above by Beenthere is measured in "Maxwells per square centimeter," aka "Gauss." Each core material will saturate at a given density. If we try to squeeze more power through the field after that, the whole thing just heats up instead. Then insulation fails. Then we cuss a lot amidst the nasty smelling smoke.

5. tronics Member

Apr 16, 2008
14
0
thats right an the hysterisi leaf, what material is the core going to made from, cos youll have eddy currents, copper loses and iron losses