Recommendations for 60V 20+A DC power supply to test RC brushless motors?

[LCA078]

Since you're in the US, you can get a Sorensen DCS 60V 18A 1U rackmount supply usually for around $400 or less on eBay. These are industrial-grade supplies made to work in factories, not an Amazon offering made to meet a price. Sorensen has other models with more features at higher prices and they all work well and deliver what that datasheet states. Reach out if you have questions, I own a few so can probably answer most questions.

Thanks.  I don't know much about Sorensen but there are a number for sale on ebay.  I'm guessing they are well built and will last a long time with easy use?  In other words, buying a used one on ebay is probably not too risky?

[ci11]

Since you're in the US, you can get a Sorensen DCS 60V 18A 1U rackmount supply usually for around $400 or less on eBay. These are industrial-grade supplies made to work in factories, not an Amazon offering made to meet a price. Sorensen has other models with more features at higher prices and they all work well and deliver what that datasheet states. Reach out if you have questions, I own a few so can probably answer most questions.

Thanks.  I don't know much about Sorensen but there are a number for sale on ebay.  I'm guessing they are well built and will last a long time with easy use?  In other words, buying a used one on ebay is probably not too risky?

Sorensen is currently owned by Ametek in San Diego, and along with a number of other brands like California Instruments and Elgar, make industrial quality supplies that are for continuous duty. They are usually priced at $2K and above. So yes, they are robust designs with durable, high quality components even in their DCS "no-frills" line.

Normal rules apply when buying used of course, such as getting assurance/evidence of performance as well as full disclosure of defects. I have had up to 4 and have not ever regretted buying any one of them.

[KrudyZ]

Other options are older HP models from ebay like 6012B, 6032A (both 1000W running from 120V AC) or the 6674A which is 2kW but needs 240 V input for obvious reasons.
All can be had in the $600 - 800 range.

[james_s]

Only crap PSU's have a grounded output, those that are constructed to provide a decent featureset, their outputs can be elevated considerably above mains ground, limited by PCB clearances and component limitations.

That's not true at all. I've never seen a server PSU that had floating outputs from the factory and these are certainly not crap, they're top quality industrial electronics that are designed for 24/7 service. If you're talking about lab style bench PSUs then yes those will generally have floating outputs but that isn't what I'm talking about. The server PSU or telecom "rectifier" (really just a bigger version of the server PSU) are a <$100 solution. A bench PSU capable of what the OP is asking for would cost hundreds even used with shipping on top of that. Both will work, it just depends on how much money you have vs how much you're willing to tinker around with surplus stuff.

[nctnico]

Only crap PSU's have a grounded output, those that are constructed to provide a decent featureset, their outputs can be elevated considerably above mains ground, limited by PCB clearances and component limitations.

That's not true at all. I've never seen a server PSU that had floating outputs from the factory and these are certainly not crap, they're top quality industrial electronics that are designed for 24/7 service. If you're talking about lab style bench PSUs then yes those will generally have floating outputs but that isn't what I'm talking about. The server PSU or telecom "rectifier" (really just a bigger version of the server PSU) are a <$100 solution. A bench PSU capable of what the OP is asking for would cost hundreds even used with shipping on top of that. Both will work, it just depends on how much money you have vs how much you're willing to tinker around with surplus stuff.

Why bother with tinkering while you can get PSUs with adjustable output voltage AND current limit for a reasonable price? For testing purposes where you need different voltages / current limits a server or telecom PSU just isn't the right solution. These will only be worthwhile for a long term (several years) fixed test setup.

[Circlotron]

One thing's for sure - with one of those ducted fans for a load, aim it in the right direction and you won't have any trouble keeping your power supply cool!

[LCA078]

Sorensen is currently owned by Ametek in San Diego, and along with a number of other brands like California Instruments and Elgar, make industrial quality supplies that are for continuous duty. They are usually priced at $2K and above. So yes, they are robust designs with durable, high quality components even in their DCS "no-frills" line.

Normal rules apply when buying used of course, such as getting assurance/evidence of performance as well as full disclosure of defects. I have had up to 4 and have not ever regretted buying any one of them.

Other options are older HP models from ebay like 6012B, 6032A (both 1000W running from 120V AC) or the 6674A which is 2kW but needs 240 V input for obvious reasons.
All can be had in the $600 - 800 range.

Thanks for the inputs.  HP (Agilent) is obviously a familiar high quality name which is why, IMHO, they carry the price premium and have fewer selections available on ebay.  From what I can see on ebay, the Sorensen is probably the way to go for an used industrial power supply. 

I'll probably end up purchasing a Gophert power supply from Aliexpress and a used industrial one (Sorensen or HP or other high-end version) off ebay to ensure I always have a primary and alternate available.  I really need to run dedicated 110/220VAC lines from the main breaker box to my "bench" in the garage.  The first win in building a bench was convincing my wife the garage was destined to be a mini-electronics lab instead a place to park your car....so baby steps on this one.

One thing's for sure - with one of those ducted fans for a load, aim it in the right direction and you won't have any trouble keeping your power supply cool!

Yes- those things put out the airflow!  We're currently using off-the-shelf battery powered leaf blowers which use 80-90mm EDF's to produce the needed airflow- and those things are mini-hurricanes.  But we know our efficiencies are really low since they are optimized for high velocity (thrust).  We believe going up in fan size but dropping way down on the power will be a huge increase in battery life as we're just trying to use these systems to ventilate (move large volumes of air) compared to produce lift (lower volumes of air at a high velocity).  No issues with finding enough airflow to cool components in our design!

[LCA078]

I have the CPS 6017, which I use for that exact purpose and it works very well for the price. At 1000W, they are pretty close to what you can pull from a regular US wall plug.

Awesome- good feedback.  Also, are you saying you use the 6017 to power BLDC's?  If so, I need to pick your brain a bit on correctly setting up the ESC and input signals.

[LCA078]

I also found these Sorensen bench top models.  I really like the front outputs for a bench set but I'm definitely paying a premium for it (2x the price for a used Sorensen vs. the Gophert from Aliexpress).

[Black Phoenix]

You could also look for the Tdk-Lambda PSUs. I tend to come around them often in the used market. Most are the single unit with output lungs on the back but others have banana style output on the front, with jumpers on the back for parallel and series connection with other similar units via RS232/485.

[ci11]

The 1.2 kW DCS and XFR models I use are 1U rackmounts with outputs at the rear. none at the front. These are stacked with other rackmount PSUs below the bench off to one side, leaving the bench for the DUT and often an AWG, a scope, an analyzer and a few DMMs. For my work, there are usually various DC and AC voltages required at the DUT at any one time so this is actually a necessity.

[james_s]

Why bother with tinkering while you can get PSUs with adjustable output voltage AND current limit for a reasonable price? For testing purposes where you need different voltages / current limits a server or telecom PSU just isn't the right solution. These will only be worthwhile for a long term (several years) fixed test setup.

What is a "reasonable price"? He didn't say he wanted adjustable output voltage or current, if that's needed then it needs to be specified.

For what it's worth, I use a 12V server PSU for testing brushless RC motors on the bench. Almost all of my aircraft run on 3 cell 12V batteries so a 12V power supply is fine. I don't need variable voltage and I don't need variable current, thus my suggestions are based on my own use for the stated purpose.

[nctnico]

Why bother with tinkering while you can get PSUs with adjustable output voltage AND current limit for a reasonable price? For testing purposes where you need different voltages / current limits a server or telecom PSU just isn't the right solution. These will only be worthwhile for a long term (several years) fixed test setup.

What is a "reasonable price"? He didn't say he wanted adjustable output voltage or current, if that's needed then it needs to be specified.

It says right in the OP's first post. 12V to 50V. Current limiting is very useful for testing high power systems. If something goes wrong then at least the amount of power that can do damage is limited. I don't know if you have ever watched a 70A automotive relay burn out on your bench but I have. Current limiting in the PSU I used saved the day.

[james_s]

I've had ESCs fail shorted on several occasions, the server PSU shuts down instantly. The don't have current limiting in the sense of a bench PSU but they have over-current shutdown, you can short the output wires directly and it barely sparks. It's actually annoying at times, if you try to use one to power a brushed motor directly the inrush will usually cause it to trip. On the other hand the LiPo batteries that are used to power these things in the field have no current limiting or protection at all, they tend to cause things to catch fire when something goes wrong.

[nctnico]

I've had ESCs fail shorted on several occasions, the server PSU shuts down instantly. The don't have current limiting in the sense of a bench PSU but they have over-current shutdown,

The more feature rich bench PSUs have an electronic fuse function (typically called overcurrent protection aka OCP). So you can either have a complete shut-off or constant current as current limiting functions.