# 2 Voltage source in parallel..

1. ## 2 Voltage source in parallel..

What will be the result if we connect 2 different voltage source(say a 2v and a 1v source in parallel to each other). What will be the net voltage(For both ideal and non ideal cases) if we measure voltage across the parallely connected voltage sources??

My opinion is it will be the least of two(In my example it may be 1 v) in the ideal case as if we connect a 10 v and short it(almost similar to 0v connected in parallel with 10v),the battery gets drained and results in 0v.. But will it be the case really? What will be the result if we connect a 2v and 1v in parallel???

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2. ## 2 Voltage source in parallel..

i think it will be the larger where the smaller will charge from the larger (i.e. the smaller will be considered as a load)

3. ## Re: 2 Voltage source in parallel..

Originally Posted by safwatonline
i think it will be the larger where the smaller will charge from the larger (i.e. the smaller will be considered as a load)
Then why is it that 0v(short) is draining the battery(say 10v) actross which it is connected?? In this case,it is not charging but instead draining the battery..

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4. ## Re: 2 Voltage source in parallel..

If you connect two IDEAL dc voltage sources (bear in mind - 0Ω internal impedance) of different voltages - in theory - you will end our existance on this planet ..

In practice, voltage sources such as batteries don't have infinitely low internal impedance, so one which has higher capacity and lower internal resistance will prevail .. assuming that wires used to connect them are of sufficient cross-section ..

Regards,
IanP

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5. ## Re: 2 Voltage source in parallel..

Originally Posted by IanP
If you connect two IDEAL dc voltage sources (bear in mind - 0Ω internal impedance) of different voltages - in theory - you will end our existance on this planet ..

In practice, voltage sources such as batteries don't have infinitely low internal impedance, so one which has higher capacity and lower internal resistance will prevail .. assuming that wires used to connect them are of sufficient cross-section ..

Regards,
IanP
Ok.. But then, does it mean that the voltage measured across them will give the largest of two??(In my example of 1v and 2v,will it read as 2v assuming the connecting wire share the extra voltage??)

6. ## Re: 2 Voltage source in parallel..

In the ideal world connecting two voltage sources is impossible ..

In the real world without knowing batteries (voltage sources) internal resistances and their capacities the answer to this quesion is unknown .. voltage is not enough ..

Regards,
IanP

7. ## Re: 2 Voltage source in parallel..

Originally Posted by IanP

In the ideal world connecting two voltage sources is impossible ..

In the real world without knowing batteries (voltage sources) internal resistances and their capacities the answer to this quesion is unknown .. voltage is not enough ..

Regards,
IanP

I got the answer from another forum as it will be the diffence of the two(In my case of 1v and 2v it will be 1v they say).. Here is their anwer:

"The voltages will subtract and it will be like a short circuit of a lower voltage battery if the voltages are not equal. THe two cells simplify into one and it's like a short across the equivelant cell. Two elements connected by themselves in a single loop circuit are in parallel and in series at the same time."

Will it really be the difference of the two?? What do you feel?? My seniors who raised this question said they got the highest of 2(I.e,if its 1v and 2v,then they got 2v). But my friend said he saw in some site that it will be the rms value of the both.. But i am really confused which one is true and which one to believe.. Please help me..

P.S:I tried it practically now and i connected two batteries in parallel(one measured 1.28 and another one 1.38) I tried measuring both the sides and i got 1.28(which is the least of two) and i dont know whether it is correct.. I will try to do it with two other power source in my lab tomorrow and find out the result practically..

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8. ## Re: 2 Voltage source in parallel..

Consider this:
A 2V voltage source of 2000000000 ... 000000000000000 M(ega)Ah and 0.00000000000000000000000000000000000000000 - and another 50 millions of internal resistance - is connected to a 1V/1mAh of, say, 1mΩ, battery ..
What do you think will happen?

Don't you understand that you need more than just their voltages?

Regards,
IanP

9. ## Re: 2 Voltage source in parallel..

As far as i know it depends on the output impedance of the sources and the net voltage would move towards the source with the least output impedance

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