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wdy 1
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Join Date: Apr 2013
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Current Calculating Question

04/21/2013 11:02 PM

how would I calculate the current that would be drawn by a 40uf capacitor connected to 230 volt 50hz supply
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IdeaSmith
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#1

Re: wdy 1

04/21/2013 11:43 PM

At which point in time?

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lyn
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#2

Re: wdy 1

04/22/2013 12:48 AM

Fundamentals of Electrical Engineering - Page 164 - Google Books Result

I'd ask someone who knows me, and cares, to do the work for me.

Or, learn to search.
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dvmdsc
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#3

Re: wdy 1

04/22/2013 1:05 AM

The capacitor shows an impedance of

1/ omega C

omega: 2 x 3.14 x f thus

1 / 2 x 3.14 x f (in Hz) x C (in Farad) - your result shows in Ohms

1/ 2 x 3,14 x 50 x (40) x 10 exp -6

With Ohm's Law:

I = U/R

I in Amps

U in Volts

R in Ohms

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PWSlack
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#4

Re: wdy 1

04/22/2013 3:17 AM

First calculate its impedance. Second, divide that figure into the voltage. Job done.

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Anonymous Poster #1
#8
In reply to #4

Re: wdy 1

04/22/2013 4:08 PM

as in #3?
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dvmdsc
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#9
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Re: wdy 1

04/22/2013 4:46 PM

If I calculate well:

parallel over the 230 Volts - the capacitor draws approx. 2.9 A (ampere)

and read this: consumes 664 Watts !!!

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jack of all trades
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#10
In reply to #9

Re: wdy 1

04/22/2013 6:06 PM

and read this: consumes 664 Watts !!!

Another good indication that this question is not a real-world application (unless it is for power factor correction capacitors).

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dvmdsc
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#11
In reply to #10

Re: wdy 1

04/22/2013 11:19 PM

You have a point here. Perhaps the OP wants to get rid of harmonics and higher frequency pollution at that price. It surely will put the capacitor under test because these produce extra power. Take care. D

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Epke
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#5

Re: wdy 1

04/22/2013 4:35 AM

without a limiting chare resistor close to this

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PWSlack
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#6
In reply to #5

Re: wdy 1

04/22/2013 5:47 AM

Surely there would be a circuit protective device somewhere?

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jack of all trades
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#7
In reply to #6

Re: wdy 1

04/22/2013 3:17 PM

If this is a homework question then there is no protection and the power supply has infinite capacity.

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Anonymous Poster (1); dvmdsc (3); Epke (1); IdeaSmith (1); jack of all trades (2); lyn (1); PWSlack (2)

Previous in Forum: LCI & Cycloconverters   Next in Forum: How to Calculate Winding Temperature in Transformer?

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