Author Topic: Understanding load regulation  (Read 977 times)

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Offline Rainer DynszisTopic starter

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Understanding load regulation
« on: January 13, 2020, 10:21:29 am »
Hello,

I am not sure whether I understand load regulation specs for PSUs correctly.

I believe it means that, when it says "load regulation: 0.01% + 2 mV", I can expect an open circuit voltage of 10V to drop at most by 3 mV (== 0.01% from 10V + 2mV) under load.

Is this correctly understood? (I am asking because my voltage drops farther than that.)

Thanks.
 

Offline GerryR

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Re: Understanding load regulation
« Reply #1 on: January 13, 2020, 11:41:34 am »
You are correct, but there are other specs that go along with that, like at what rated current is the load regulation stipulated, the ripple / noise in CV mode and ripple current in CC mode, recovery time from a 50% load change, etc.  If in a series regulation mode, dual supply for example, load regulation will generally be higher.  What supply are you talking about?
Still learning; good judgment comes from experience, which comes from bad judgment!!
 

Offline mvs

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Re: Understanding load regulation
« Reply #2 on: January 13, 2020, 11:59:09 am »
Is this correctly understood? (I am asking because my voltage drops farther than that.)
Yes in general... But do you measure voltage at PSU terminals or at the load? Connection wires do have some resistance and may spoil your results.
 

Offline ArthurDent

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Re: Understanding load regulation
« Reply #3 on: January 14, 2020, 12:21:16 am »
I believe the above post has the answer to your question. It is important where and how you measure the voltage and the link below has a good description of how local and remote sensing works. Lower current demands and shorter lead length help with local sensing supplies but for high current and long lead length you may need a supply with remote sensing, or compensate for the losses by measuring the voltage at the load and increasing the output at the supply.

https://community.keysight.com/community/keysight-blogs/general-electronics-measurement/blog/2018/01/25/remote-sensing-is-important-for-your-power-supply
 

Offline Jwillis

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Re: Understanding load regulation
« Reply #4 on: January 16, 2020, 10:34:17 am »
  Check your DMM . Is it a high impedance DMM or a low Impedance DMM. When checking the no load voltage you need to use a high impedance DMM .Typically 1M . Some DMM are low impedence ( as low as 3K ) . This can give incorrect readings when checking load regulation.
 


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