I would take it to mean that it is a constant voltage of 120 Volts. It has no periodic AC component that can be measured or observed. What can be measured or observed is naturally a subjective concept. It may or may not have random uncorrelated fluctuations, measureable or otherwise.Originally posted by rodn.m@May 4 2006, 11:16 AM
what is meant by the term 120 volts dc ripple free?
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the reason i ask, is that this is the term used in the SAA Wiring rules of Australia/New Zealand 2003.Originally posted by Papabravo@May 5 2006, 07:28 AM
I would take it to mean that it is a constant voltage of 120 Volts. It has no periodic AC component that can be measured or observed. What can be measured or observed is naturally a subjective concept. It may or may not have random uncorrelated fluctuations, measureable or otherwise.
I don't consider this to be a very meaningful description of a DC source. In statistical terms it suggests a voltage source with a mean of 120 volts and a variance of zero. We know this to be a physical impossibility. Even a battery has a non-zero variance. Just think of the discharge curve as describing a very low frequency ripple.
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Being Australian and also knowing a little about AS3000 the term 120VDC ripple free just means that it is DC and is not to be confused with AC unfiltered rectified AC. They have very specific voltage levels to determine who can and can't touch or work on various equipment.Originally posted by thingmaker3@May 7 2006, 01:28 PM
"SAA" = "Standards Association of Australia"
The electrical wiring rules are AS 3000
The only documents I could find with numbers on "ripple free" were so full of legalese I couldn't be sure if they were giving allowance or documenting farm animal deaths.
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To add to earlier answers regarding the general idea of 'ripple-free', you must consider it in context of the application that you are working with. I have had people propose to me "ripple-free" Chebyshev filter designs for image-filtering. For those that are familiar with Chebyshev filter designs, they inherently have pass-band ripples traded against steep transition regions, but can easily be desribed as 'ripple-free' by their designers because the net effect on the image acquisition process is minimal and unaffected by the ripples.Originally posted by rodn.m@May 4 2006, 03:16 PM
what is meant by the term 120 volts dc ripple free?
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Heres a picture with ripple on the top and one below that has less ripple. If there were no ripple the line would be flat. That would be accomplished by using coils and capacitors in the circuit.Originally posted by rodn.m@May 4 2006, 08:16 AM
what is meant by the term 120 volts dc ripple free?
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by Aaron Carman
by Jake Hertz
by Jake Hertz
by Jerry Twomey