Turning A Bad Bench Supply Into A Better Bench Supply

‘Tis the season for dropping hints on what new doodads would make a hacker happy, and we have to admit to doing a little virtual window shopping ourselves. And as a decent bench power supply is on our list, it was no surprise to see videos reviews that the hive mind thinks will help us make a choice pop up in our feed. It’s a magical time to be alive.

What did surprise us was this video on a mashup of two power supplies, both of which we’ve been eyeing, with the result being one nicely hacked programmable bench PSU. It comes to us courtesy of [jeffescortlx], who suffered with one of those no-name, low-end 30V-5A bench supplies that has significant lag when changing the settings, to the point that it’s difficult to use, not to mention dangerous for sensitive components.

So he got a hold of a Riden RD6006 programmable buck converter, which is something like those ubiquitous DPS power supply modules we’ve seen so much of, only on steroids. The Riden takes up to 70V input and turns it into a 0-60V output at up to 6 amps, at constant current or constant voltage. It also just happens to (almost) fit as a replacement for the faceplate of the dodgy old supply. A few SMD resistors simulate the original front panel pots being pegged so that the supply outputs maximum voltage and current, and a little finagling with the case and fan was needed to fit everything up, but the finished product actually looks really good, and fixes all the problems of the original.

We love this hack, and may well cobble this together for our bench.

23 thoughts on “Turning A Bad Bench Supply Into A Better Bench Supply

  1. I like your hack / bash turning a mediocre power supply into a great one. Most impressed by the built in scope and battery charge feature, the latter is what most of us do anyway. Or cranking up the current to burn dendrites out of 0V NiCd’s.

    1. Indeed, that front panel is pretty magic stuff, particularly for the price (so for the heads up I thank you). A very neat blending of bits that almost looks like it was from the factory. Will work well and for a price it is hard to argue with – I’ve been looking for some cheap but capable bench supplies for awhile and not seen anything that seems this capable near this price.

    1. You can calibrate both the output and the displayed values for voltage and current very finely through the PC software via USB cable. This includes both offset and slope over two points to get the whole range accurate, though mine was pretty close to start with.

  2. OK… Look at the specs on this “programmable buck converter”… They are complete BS. Has anyone done performance/transient analysis on these things? I shudder to think about the results…

    1. Benefits? This is a lot better than the old DPS, has a nice and responsive interface and remote control via USB or WiFi.
      I’d like a better software on the PC side, though. The original is a bit rough to use.

  3. Wow, that video was a painful watch. Complete waste of time… 40 minutes in the first video and he failed to do a majority of even the most basic measurements one would do when qualifying/validating a buck converter? And then, a 15 minute follow up video when he again tries to characterize ripple at a fixed operating point and decides he needs coax and a terminator to do it??? I realize he’s a maker type and not an EE but the data presented in both videos could be summed up in about 60 seconds and provides little actual information regarding the performance of the buck… Cringe worthy…

    No operating conditions specified in the power supply datasheet; Oddball specs like input voltage accuracy…? What? Is that a spec for the ADC measuring input? It certainly is not trying to specify the output accuracy of the upstream buck… They clearly care nothing for that without a single PSRR spec????? No transient specs, no bandwidth spec, no test conditions, these numbers on that RD6006 page are literally meaningless.

    IMO it’s not even worth characterizing this chinesium when you can get on eBay and buy a real power supply secondhand – Sorensen, xantrex, you name it – For barely twice that price – And you’ll have something that will actually perform well, will last a lifetime, and that doesn’t depend on another upstream supply to operate… You don’t need the fancy screen – That’s what your quality (non-chinesium) DMM you also purchased secondhand on eBay is for…

    I get it – hobbyists like to populate their bench with blinky things – but if you are serious about electronics in the long term, don’t buy this kind of junk.

      1. I know nothing of his background, my opinion is based on:
        1) He appears to have had this ‘eevblog’ site for a long time
        2) In 40 minutes he failed to perform most of even the most basic characterization that an EE would perform when validating a power supply.
        3) He followed the 40 minute video with another 15 minute video showing a less incorrect but still very overly difficult way to measure ripple voltage and explained it in a way that seemed to indicate that he didn’t fully understand it – Maybe regurgitating something someone else told him, for the first time?

        Fifty five minutes is enough to not only show characterization of every critical parameter of that buck, but also show many of the less important parameters as well, and also go through an architecture and component analysis of the PCB… No offense, but those videos are painful even compared to an EE school project video which I have seen many of. I know nothing of his other videos, maybe he seems more informed at times but these 2 videos are really, really, really bad… I think a ‘maker’ might actually be offended if you compared their work to something like these videos and asserted that these videos were better than their work, no matter what that work was……

        Again, not trying to be offensive, I’m just making observations, asserting some basic hypothesis *oh* and apparently defending makers here ;)

        1. I am not saying this to offend you, or anyone. And I genuinely mean what I am saying here. I wish you would have the time or inclination to make EE videos.

          I understand that Dave puts a lot of time, energy and goodwill into making his videos. But I have always found them lacking in information density, and sometimes accuracy. I agree with your point that 50 mins should be more than enough to characterize every parameter of a buck converter. And when he does do it (in a later video, I found that he characterized impractical operating conditions. But the fact remains. No one has made another video on the subject.

          I do wish more trained professionals would put out educational content.

      2. Ok, I looked him up, he has no formal training, so that makes sense, and I just want to say that I am not trying to pick on him for being uneducated. It looks like things must have been more lax in Australia back in the day and he got in without an education and got some experience working with EE’s. I would bet that he hit the ceiling that many electronics techs hit where you realize you can either go get your EE degree and move on to actual design, or move on, and he moved on. That is great, and good for him. The hands on stuff does get old after a while.
        There is nothing wrong with being a hobbyist, nor a maker at all and you can learn a lot of practical, hands-on, very useful skills without a degree. PCB design is a good example – As long as you are supervised(mentored) by good EE’s, and you are capable of self educating yourself so that you understand what they are asking you to do, you can do good quality layouts for all sorts of power and other applications without a degree. RF, high frequency and things which require heavy simulation are probably a no go for many people, but there is plenty of PCB design that can still be done without simulation.

      3. @NATO
        Ouch. You really are reinforcing the stereotype that an engineer with a degree thinks they are better than everyone else… failing to note that an engineer can pass exams either by regurgitating or by understanding, and they both end up with *exactly* the same ticket.

        I’ve worked with both, and I’ve also worked with techs that would run rings around almost any engineer you could name! Yes, there are good techs and bad techs, but a tech does not glide through life by shoving a degree in your face and talking loud.

  4. Fred,

    I am not at all trying to say that. In fact I thought I went to great length to explain that I believe there is nothing wrong with any path that someone chooses to take in the electrical industry – It is a great industry with nearly unlimited opportunity for someone who wants to push themselves.

    My point is that without a strong theoretical background, including both deep instructional and hands on experience in all of the necessary concepts starting with calculus and moving to analog and digital design, electromagnetic theory, etc – You simply can not excel as an electrical engineer in the EE industry of today, as well as the industry of the past 20 years, because you simply don’t know what’s going on around you. This is why the blog guy couldn’t adequately explain *why* the inductive ringing was occuring and also did not appear to understand the underlying theory when explaining what a transmission line is in the second video… Which is one of the first concepts you are exposed to in a basic university level EM course for an EE program.

    Again, I need to state, there is nothing wrong with this! My point was simply that there is absolutely no replacement for 4 solid years of pounding ridiculous amounts of advanced theory into one’s brain, with each class building on the previous, and so forth. You will not be hired to do real electrical engineering without one. You could certainly be a technician without one; You could even go into one of the many electrical-related jobs which include the word “engineer” in the title but don’t actually require any actual EE design work.

    Now, in regards to your “techs that would run rings around almost any engineer you could name”… I’m not sure that I completely understand what you are talking about; techs do hands on work such as PCB assembly, basic PCB design/redesign, test fixtures, etc… Engineers design electrical circuits and systems using electrical design theory.
    Are you trying to compare a good EE technician (which is often hard to find and very valuable, love these guys!) with the good percentage of employees who have “electrical engineer” or some variant thereof in their title who are really just useless trash(with respect to EE) waiting for the next layoff. This unfortunately seems to be common in any industry and the bottom line is that some of these people just never had what it took to be an engineer, and the rest just don’t push themselves. This in a way illustrates a big problem in engineering degrees nowadays – I encounter a great number of EE, CE and ME graduates who seem to have no real interest in their field, nor did they have it before they went into school, and graduate after 4 years with near zero passion for their field. I think these people must pick STEM degrees because of the salary prospects, and I strongly believe this is a huge waste and disgusting dilution of a great field. Fortunately these people seem to rapidly drop out in this competitive industry nowadays, they can go work at mcdonalds to pay off those student loans ;)

    1. @NATO
      Your last paragraph gave me a chuckle…. I’ve seen plenty of those ‘engineers’ you speak of that have no passion and drag the reputation of good engineers down with them.
      And yes, I am referring to those EE technicians you mention, a difference perhaps being that the ‘techs’ I refer to *do* engineering, but don’t have a piece of paper from a university to tell them thay can (or can’t). As with most things in life there are good and bad doctors, burger flippers, architects, truck drivers, pizza chefs, laywers (although maybe not that last one!) and no piece of paper is going to tell you which is which.

      I agree that Dave’s videos are long winded and after watching a couple several years back, I simply don’t watch them anymore.

      Your posts did come across as pretty harsh, although I do think we generally agree.

  5. I don’t mean to be harsh I just seem to see things more black and white as I get older. Gray areas tire me. Excellent EE technicians are gems which should be retained at all costs, I would hire an excellent EE technician at a higher salary than a mid level EE in many cases. The sad reality is that many EE who are capable of good design will stubbornly refuse to develop their hands on skills and actually learn to solder so this technician “glue” will always be critical. On several occasions in the past, I have lost very good EE tech due to serious attitude problems from and mistreatment by these “useless engineer” type, and so I harbor some resentment towards these cretins and have little tolerance for their lack of passion for their industry and for their lack of interest in engaging in the joy of engineering with their peers. I realize that this type will always be present especially as a team grows and I work really hard to try and weed these people out as early as possible. You don’t have to have been interested in EE/ME/etc as a child to become an engineer after school, but you had better have a passion for it after school. Otherwise I have no use for you and neither should anyone else.

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