CC CV module for bench power suply

So I have an old ATX computer power supply that I want to convert into a bench top power supply.
I’m thinking about using 3.3v, 5v and the 12v line. However I also want to have a constant current en constant voltage module.
That way I have acces to a couple standaard ready to go voltage settings and the ability to regulate to whatever I need. (handy for testing drivers/leds)

Here comes the question, does anyone know a decent dc-dc cc cv adjustable converter?

I was thinking of using one of these:

(this one also looks good:RIDEN® DPS3012 32V 12A Buck einstellbares DC-Konstantspannungsnetzteil-Modul Sale - Banggood Deutschland-arrival notice-arrival notice)
http://www.banggood.com/LTC3780-Automatic-Buck-Boost-Constant-Current-Power-Module-p-990459.html

Obviously, the first one already has a display and a potmeter to change the settings. But the other one is cheaper… :smiley: :smiley: And is also a boost converter.

So does anyone have experience with one of these modules? Or with creating a bench power supply from an old computer power supply?

I cant help but I’m sure someone here will. All the best for the project.

I have converted many computer PSU into 12V adapters for powering up LED strips for commercial use with great results, compared to standards converters (see below), computer PSU are far more stable, runs cooler, comes pre-wired, and cheaper! I have a 400W PSU powering 6x 5M LED strips drawing close to 30w each, it operates 10hrs a day 356 days a year, so far zero problem. I’m sure it will work great for your application.

The first one you linked is very good but for a full range power supply unit I would also get a boost converter for when you need above 12V, such as this one:

There is also this one -

http://www.ebay.com.au/itm/High-Quality-5A-Constant-Current-Voltage-LED-Driver-Battery-Step-down-Module-GS-/252406826717?hash=item3ac49e86dd:g:TmcAAOSwLmVXD1KE

I was using that for a little while. Fine for testing leds etc… don’t know how accurate it really is but can’t complain for the price. If you need more than 12v though….

I have in the mail the second one you linked. I think my power supply goes up the 18v so that should be enough to test most things for me.

That’s what is was thinking too. The second one I linked does both buck and boost.

Have seen that one too, looks good except I just want more current :smiley:

Where did you order it?
I think I’ll go with the second one that does both buck and boost. The first one looks nice but don’t need all those features.

If you connect an old ATX directly to these power strips - how do you control the current going to the LEDs? Or is there no need for this? I guess you don’t have dimming and just an on/off switch ? Are these strips actually dimmable?

I was planning to do this in the kitchen but wasn’t sure which CRI/LED temperature to go for and how good the strips on Gearbest, banggood etc. are quality-wise.

Thanks.

I will let will34 answer as well. But I believe these strips are controlled by voltage. At 12v there is only so much current that the led will draw so it limits the current by limiting the voltage. Now, the led itself is current driven, so the ideal way of powering them is by constant current. However, it is common practice to control these strips with voltage. It means that the current will fluctuate some with temperature, but not enough to make it a concern. Will34 may use a cc source, idk, but many just power them with 12v and let them do their thing.

Reusing old devices may sound smart but sometimes it's more trouble than its worth.

In order to properly set up some sort of decent CC/CV supply not only you'll need CC/CV modules, but: voltmeter, amperimeter, connectors, switches, box, etc. Of course, you may not need all of this stuff.

A good looking new module: B900W NC DC Constant Current Power Supply Boost Module Ammeter; having a a high output voltage allows us to, for example, run more led stuff in series. If you have buck needs, you can also add some sort of buck unit to the equation.

Now, take a look here: KPS3010D Adjustable High precision double LED display switch DC Power Supply protection function 30V10A 110V-230V 0.1V/0.01A EU

Looks like a real bargain to me…

EDIT. Recently reviewed here:

These strips are resistor ballasted to operate safely with a standard voltage controlled supply, generally at 12V, designed for the dumb end-consumer. Of course, dimmed they can be by carefully adjusting (reducing) the input voltage (something you may not be able to do on a PC PSU, but is doable on the commercial 12V units will34 does not seem to like).

Cheers ^:)

You can easily find a usable module on ebay with display and adjustment.

Check some youtube videos by “Julian Ilett”, he often plays with that type of modules.

Be careful with type:
Boost: Output voltage will ALWAYS be input voltage or higher, this do not really work for a universal constant current driver!
Buck: Output voltage will ALWAYS be lower than input voltage.
Buck-boost: Output can be above or below input voltage.

I actually was debating making a review for the power supplies you listed in the OP. I bought both the DP50V5A and the DPS3012 (with my own money for the record).

If people would like a proper review I could try to do it soon, I tend to kinda go overboard on reviews so I don’t generally do them much anymore. Spending 2-3 days on a single item review was just plain exhausting lol.

The long and short of it though is I LOVE both of those and they are worth every penny. I tried playing with some analog setups from ebay and they are a waste of time.

I scoped them out on my cheap oscilloscope and they have a very clean signal and they are surprisingly accurate as well.

You can get this direct from the manufactures Ailexpress store here: http://www.aliexpress.com/store/group/Power-Supply-module/923042_252253169.html

I have talked to the guy that designed it a few times and he is very helpful and responsive. He has been wanting me to do a review for the larger DPS5015 for a little while now.

I mounted the DP50V5A in an ATX power supply and due to being a buck supply it is limited to around 11 volts. The DPS3012 I got a “48 volt” (it is adjustable from around 30v to 50 volts in reality) and it works over the entire range. The DPS I mounted in a custom made acrylic case that I really like.

The biggest recommendation is just spend the extra for a DPS model, the firmware is much easier to use, although there is still room for improvements.

You simply can not match the bang for the buck on these, which is why I got them. I don’t mind spending more when it gets me a proudct worth the extra cost but I won’t waste more money on something that doesn’t give me something tangibly better.

When using a fixed voltage power supply each type of LED strip will draw different current, if you look closely into them you’ll see a small resistor placed between every 3 LEDs in series, and this is the same reason you can cut the strip on every section of 3. The lower the resistance the brighter it is, but nowadays the chinese have been using high resistance (240 vs 360) in order to prolong the life of the emitters in cheap strips.

To controll brightness you will need to use a LED dimming box which is essentially a PWM driver like in our flashlights but this is usually very high freq and not noticeable. You can also use voltage regulation to controll the current using large resistors.

For kitchen I’d recommend using solid strips, those that are mounted on aluminium flat bars and comes with a U shaped rail heatsink, this way you don’t need to worry about LEDs going yellow after sometime due to heat.

A general rule of thumb when buying LED strips is to buy them all at once from the same source to avoid tint inconsistency, I didn’t know this and I used to have both CW and BW (blue white) in my kitchen, despite having ordered the very same SKU from banggood, just different time. The CW one also had a lower value resistor making it look much brighter.

Best tint for kitchen in my opinion is pure cool white 5,700-6500K, not blueish or yellowish just pure CW. But for some people it can be too commercial-looking like a restaurant and it also makes the food look a bit dull, in that case you may want to try NW 4,500-5000k.

It’s mostly the ‘DIY’ part that I find interesting. Especially getting a voltmeter, ammeter, connectors, switches, box, etc and make something with it.

That’s an interesting boost module, it has some decent amps but it’s only a boost converter.

I’ve seen that bench power supply in a couple webshops here in Holland too. Not too expensive but as I said, it is the DIY part that I like.

Thanks for that youtube channel.
Just watched this youtube vid of him. Its about the ‘LTC3780 Automatic Buck Boost Constant Current Power Module’ that I linked. He was positive about it.

Awesome! If you have the time, do a (short :p) review.
Nice to hear that the maker/owner/whatever responsive and helpfull, you dont see that very often. Too me that says quality.

Well, I tend to over think this and keep changing my mind on what I should do. So I think I’ll stop now and just go with the LTC3780 buck-boost converter. Now I need to think in what I should put all this… Lol.

Thanks guys.

Yes, I was quite surprised at the quality and accuracy which is why I had first contacted the manufacture.

I have one of those converters you are talking about and unless you need the Boost part of the driver, I can tell you that it is just short of impossible to actually use in real life as a bench power supply. Works great as a fixed power supply for a project however.

This simply comes down to not having any meters to see what it is doing and if you buy meters then the cost ends up not being that much cheaper then one of the DPS units. This is why I gave up on the analog driver and went with the digital, the cost of making the analog usable as a bench power supply was as much as just buying the other units and it would not be nearly as good or easy to use.

Trying to accurately change the voltage and current with the pots is not easy and can be quite risky as the only way to know what it is set to is to turn it on and hope you have the settings right. It was after not having them right and popping an LED that I started looking for better options.

definitely for bench use get the DPS3012. For the extra money it looks well made a @ 12A it has good heat sink. I like that one. Been kinda in the market for a buck - boost and seen most of Julien’s vids (subscriber), That DPS3012 is the nicest I have seen for the money.

Review please Texas Ace. And BTW, you would like my ATX 12V powered, LED lighting on my reloading bench and 12V heated lube sizer. 12V 20W heater cartridges from 3D printer and thermally regulated.

@ will34: on your 5M strip runs, are you applying power at both ends? I have had some strips slightly dim on the last few feet. May be due to different resistors on different rolls, but powering both ends seems to eliminate it.

Posted review here: Review of DP50V5A & DPS3012 bench top power supply modules, best bang for the buck around!