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moomoo
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Continuous DC Current and Peak Current

08/06/2012 10:29 AM

Hi,

I saw this statement when going through a standard for lighting equipment and i feel confused by this statement.

"Maximum output voltage does not exceed 42.4 V peak for alternating current, 60 V for continuous direct current. These products are intended primarily to providepower to low voltage, electrically operated devices"

I thought that it should be stated the other way round. ie 60V peak and 42.4V continious dc current? Please adivse ur inputs.

Thanks

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PWSlack
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#1

Re: continious dc currrent and peak current.

08/06/2012 11:15 AM

<...thought that...>

Hint: 60/42.4≈√2, so think again.

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moomoo
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#2
In reply to #1

Re: continious dc currrent and peak current.

08/06/2012 11:45 AM

But i thought Vp/Root 2 = Vrms?. So in this case , Dont u think the author mistakenly used Vp as 42.4 and Vrms as 60v?

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redfred
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#3
In reply to #2

Re: continuous dc current and peak current.

08/06/2012 11:55 AM

No, the most common method of expressing VAC is an RMS measurement. So if the RMS voltage is 42.4 VAC then what will be the peak voltage?

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moomoo
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#4
In reply to #3

Re: continuous dc current and peak current.

08/06/2012 12:07 PM

60V?.

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Wal
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#7
In reply to #3

Re: continuous dc current and peak current.

08/07/2012 1:27 AM

OP said 42.4VAC PEAK not RMS.

Moomoo is right.

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Carl Pugh
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#5

Re: Continuous DC Current and Peak Current.

08/06/2012 12:14 PM

moomoo is correct.

The numbers are backwards.
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moomoo
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#6
In reply to #5

Re: Continuous DC Current and Peak Current.

08/06/2012 8:57 PM

I thought so Carl, and surprisingly this is from one of the safety standards bible!

Thanks !

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Wal
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#8
In reply to #6

Re: Continuous DC Current and Peak Current.

08/07/2012 1:29 AM

Vote "no" in the off topic for moomoo.

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dkwarner
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#13
In reply to #8

Re: Continuous DC Current and Peak Current.

08/07/2012 9:50 AM

Done!

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james denoil4
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#9

Re: Continuous DC Current and Peak Current

08/07/2012 2:51 AM

thank you...nice post..
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phph001
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#10

Re: Continuous DC Current and Peak Current

08/07/2012 5:24 AM

"Maximum output voltage does not exceed 42.4 V peak for alternating current, 60 V for continuous direct current."

If we are talking AC then I agree the numbers are the wrong way round, but where does the DC fit in?
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Snel
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#11

Re: Continuous DC Current and Peak Current

08/07/2012 8:26 AM

Maybe what is meant is

"Maximum output voltage does not exceed 42.4 V [rms] peak ("peak" meaning an overvoltage for some limited time, not the instantaneous peak voltage) for alternating current, 60 V for continuous ("continuous" meaning "a continuously applied voltage", not necessarily a DC voltage) direct current".

It's a very confusing text anyway, probably a translation. Remember "direct current" is literally "continuous current" in other languages.

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Wal
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#12

Re: Continuous DC Current and Peak Current

08/07/2012 8:58 AM

If moomoo is still in the vendor selection stage of this project i'd suggest that he selects to NOT buy this product.

If they can't get the documentation right then what else is wrong? Doesn't bode well for technical or any other after sales support in my experience.

Technical documentation does not tolerate poetic license. Metaphors, similes, implications and their ilk have no place here.

If you have knowledgeable folk having to have a go at paraphrasing a specification for it to make sense then the world's going to hell in a handbasket.

OP, could you tell us the country of origin for this lighting equipment please?

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moomoo
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#16
In reply to #12

Re: Continuous DC Current and Peak Current

08/08/2012 11:17 PM

Hi Wall,

Actually this statement is written in one of the safety standards for class 2 power supplies, and i m still pulling my hair to understand what this means. I am sure they know what they are writing,but somehow it doesnt make sense to my common sense!

Regards.

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Wal
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#17
In reply to #16

Re: Continuous DC Current and Peak Current

08/09/2012 12:27 AM

I get it.

For a power supply to be considered as class 2 then these maximum parameters can't be exceeded.

There doesn't need to be any correlation between the AC and DC values.

OR

It could still be a typo that got missed in the proof reading...

Can you contact the authors of the standard for clarification?

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The.Tinkerer
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#14

Re: Continuous DC Current and Peak Current

08/07/2012 10:57 AM

If this was a standard for lighting...why is there an output voltage at all?

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Wal
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#15
In reply to #14

Re: Continuous DC Current and Peak Current

08/07/2012 11:29 AM

These products are intended primarily to provide power to...

I think it is lighting control/energisation apparatus not the luminaires themselves.

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Users who posted comments:

Carl Pugh (1); dkwarner (1); james denoil4 (1); moomoo (4); phph001 (1); PWSlack (1); redfred (1); Snel (1); The.Tinkerer (1); Wal (5)

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