EEVblog Electronics Community Forum
Products => Other Equipment & Products => Topic started by: Hugoneus on August 30, 2011, 09:06:49 pm
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In this episode Shahriar reviews the brand new Rigol DP1116A and DP1308A programmable power supplies. Furthermore, the power supply features are compared against an Agilent dual output power supply.
“DP1308A & DP1116A are high-performance programmable linear DC power supply. They have excellent features including timed outputs and tracking capabilities; extremely clean ripple and noise, comprehensive over-voltage, over current, over-temperature protection, a large and clear user interface, super performance specifications,and multiple standard interfaces. The DP1308A & DP1116A meet the requirements of various forms desktop and integrated system testing. DP1308A & DP1116A are widely used in research and development, education, industrial control, mobile communication, and product testing, etc.”
The MSRP for both products is $849. Rigol offers a 30 day no-questions-asked return policy and a 3 year warranty. They also provide an excellent local technical support out of tropical Cleveland, Ohio.
Please visit:
http://www.TheSignalPath.com (http://www.TheSignalPath.com)
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There is also a tiny quiz in this video. Please feel free to discuss it here.
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Nice series of videos on this. They were clear and as concise as they could be given that you not only covered the review of the units themselves but also gave a quick background on how they would be used.
Good job.
I will leave the quiz to those who aren't sure :)
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Thank you!
A few people answered the quiz on YouTube. I guess I ought to make these quizzes harder!
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Do you post the quiz answers somewhere?
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Generally people answer the quizzes either on the site or on the YouTube video. Someone has already answered the question on the website! ;)
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Great review and great power supplies! I want one, too :)
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Thanks for making this very good introduction to programmable supplies and what appears as a review of the Rigol models. The imagry is very clear, and your lab is incredibly clean and well equipped.
Its great you provide over 1 hour of material. I wish I heard more about the Rigol against the Agilent, as aside from the ripple, I'd like to see its OVP protection and line regulation performance; program ability is moot if the basic power section isn't as clean or protected as Agilents, or as written in the spec sheet. A tear down would help too, as looking at the construction and parts will give me an idea on what it can do.
It could help more experienced folks if basics are separated from a product review.
The noise demonstrated on the scope is much higher than the Rigol or Agilent specification, a good low cost [ $< 80] linear supply can easily deliver under 1Vrms, > 5-10x less than the values demonstrated. It would be a shame to have programmability and then get such noise, if indeed this occurs.
The waveforms however, suggest there is something else causing it, not likely from the supply output; they look very much like SMPS noise from any device sharing the same ground and branch circuit, also it would be odd to have such noise in, what I hear are linear supplies.
I would bet those waveforms are there with scope probes alone, or if the user touched the probes [ as I think happened], or when attached to the PSU with power off; taking the power cord off the PSU may not appreciably affect those spurs. When the probes are attached to the Agilent, it seems more constructive interference. When checking ripple I insure PSU outputs are floating, but the measuring device too must float to reduce EMI and ground loops; an earth grounded scope will pick up Wifi, nearby SMPS - even the scopes own PSU, cellphones and radio transmissions, so the overall noise is a mix of many sources, not necessarily that of the PSU being tested.
Looking forward to more reviews. Much appreciated!
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Thank you for the feedback.
The noise is rather unusual to me as well. I am planning to double check it.
But there is one thing to consider. If the noise is indeed coming from the AC line (and goes right through the power supply), this is undesired function of the supply. A good lab supply should filter that type of noise. But I will try to re-measure and report back to you.
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You're welcome. The noise is typically picked up by the scope, unlikely through the PSU, if it did that would be bad, and worth checking for.
When I do these tests, I use a battery powered handheld scope so its fully floating, and it removes any possibility of ground or mains induced noise. The baselines are very clean to begin with unlike the bench scopes. Use shortest probe leads possible, well shielded, and low ohm load, I use loads to get maxmium output V and A, and it avoids impedance mismatch artifacts.
Typical issues:
http://www.eetimes.com/design/power-management-design/4012479/Power-Tip-6-Accurately-Measuring-Power-Supply-Ripple (http://www.eetimes.com/design/power-management-design/4012479/Power-Tip-6-Accurately-Measuring-Power-Supply-Ripple)
http://www.digikey.com/Web%20Export/Supplier%20Content/Excelsys_633/PDF/excelsys-measuring-ripple-noise.pdf?redirected=1 (http://www.digikey.com/Web%20Export/Supplier%20Content/Excelsys_633/PDF/excelsys-measuring-ripple-noise.pdf?redirected=1)
Thank you for the feedback.
The noise is rather unusual to me as well. I am planning to double check it.
But there is one thing to consider. If the noise is indeed coming from the AC line (and goes right through the power supply), this is undesired function of the supply. A good lab supply should filter that type of noise. But I will try to re-measure and report back to you.
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Yada yada yada Take it apart show us the inside. Rigol used high quality Nichicon caps in their oscilloscope, I like to see if this the the case with the PSUs.
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Generally people answer the quizzes either on the site or on the YouTube video. Someone has already answered the question on the website! ;)
Sorry to bump this up, but a relevant question arises concerning the feature of live Volts measure when the output is disabled. This PSU (DP1308A) doesn't have it, while the DP1116A has.
Any Firmware updates known for this "bug" as of yet ?