Ok, I got the parts ordered to convert 10 pairs of power supplies into series wired units as well as 2 pairs of power supplies to modify.

The plan is to use 1 pair of the power supplies to record an instructional video then offer two conversion kits:

Short kit contains:

(1) Nylon screw and washer
(2) Pin headers to plug into the main board to turn the power supply on.
(1) Zener diode to provide a dc- case ground if we have a fault.
(2) 30A keystone binding posts. (use ring terminals for more current)
(1) Angle aluminum to make the front plate out of and fasten power supplies together.
(1) Drill template for angle aluminum.
(1) Instructional video.

To complete the short kit you will need some ring terminals, some 10awg wire, and some heat shrink. You will also need to build all of the jumpers, mount the binding posts, solder jumpers on the pin header, and grind down one of the board mounts on one of the power supplies. Cost for the short kit will be $28 shipped.

Full Kit contains:

(1) Everything in the short kit.
(2) Jumpers with ring terminals to wire the power supplies in series or parallel.
(4) Internal jumper wires to go from the binding posts to the main board.
(1) Holes drilled in the angle aluminum with the jumps and binding posts installed.
(1) Heat shrink tubing.

The full kit does not require any soldering or drilling. The only thing you need to do is remove the board in one of the power supplies, grind down one of the mounts with the dremel, then bolt it together according to the instructions. Cost for the full kit is $45 shipped.

When I get the parts in then I'll setup a website with paypal to accept orders. I'll probably only do a couple of runs of these since I really don't want to get into business, but I did want to make a convenient way for others to modify power supplies without the need to chase down all of the parts.

Please note that while I think this setup is as safe as it can be, I cannot be responsible for your success in modifying these parts or any hazards or dangers you may be subject to.

Thanks,
schu

schu, want me to put a notice about this in the Sticky thread?

john

Originally Posted by akschu

Ok, I got the parts ordered to convert 10 pairs of power supplies into series wired units as well as 2 pairs of power supplies to modify.

The plan is to use 1 pair of the power supplies to record an instructional video then offer two conversion kits:

Short kit contains:

(1) Nylon screw and washer
(2) Pin headers to plug into the main board to turn the power supply on.
(1) Zener diode to provide a dc- case ground if we have a fault.
(2) 30A keystone binding posts. (use ring terminals for more current)
(1) Angle aluminum to make the front plate out of and fasten power supplies together.
(1) Drill template for angle aluminum.
(1) Instructional video.

To complete the short kit you will need some ring terminals, some 10awg wire, and some heat shrink. You will also need to build all of the jumpers, mount the binding posts, solder jumpers on the pin header, and grind down one of the board mounts on one of the power supplies. Cost for the short kit will be $28 shipped.

Full Kit contains:

(1) Everything in the short kit.
(2) Jumpers with ring terminals to wire the power supplies in series or parallel.
(4) Internal jumper wires to go from the binding posts to the main board.
(1) Holes drilled in the angle aluminum with the jumps and binding posts installed.
(1) Heat shrink tubing.

The full kit does not require any soldering or drilling. The only thing you need to do is remove the board in one of the power supplies, grind down one of the mounts with the dremel, then bolt it together according to the instructions. Cost for the full kit is $45 shipped.

When I get the parts in then I'll setup a website with paypal to accept orders. I'll probably only do a couple of runs of these since I really don't want to get into business, but I did want to make a convenient way for others to modify power supplies without the need to chase down all of the parts.

Please note that while I think this setup is as safe as it can be, I cannot be responsible for your success in modifying these parts or any hazards or dangers you may be subject to.

Thanks,
schu

Not yet, lemme get the parts received first.

I should also note that this is the same as the feather merchant 47a power supply, so there are probably a bit of them in the field.

schu

Just post here when you are ready. I monitor this one regularly.

Better I put it in the sticky because I can edit it into the first post.

John

Originally Posted by akschu

Not yet, lemme get the parts received first.

I should also note that this is the same as the feather merchant 47a power supply, so there are probably a bit of them in the field.

schu

Originally Posted by akschu

The plan is to use 1 pair of the power supplies to record an instructional video then offer two conversion kits:

Thanks,
schu

Man you rock, that is awesome. Have been following closely as I had no plans of going 24v until you posted this. Thanks!

The full kit is expensive, but given the amount of time and the cost of the parts, it's well worth it. Those banana jacks aren't cheap and neither are the ring terminals. Soon I'll post pictures of both kits as well as the power supplies, but for now check this out:

Can you find the difference between the two pictures? Yup, in one picture the power lab is setup for 12v at 94A and in the other it is setup for 24v at 47a.

The power supplies can comfortably run the power lab 8 at full power on a 4s battery (~650 watts) while the other two chargers are running at max.

Please note that this one is a prototype, the kits will have a single aluminum bracket that ties them together as well as have higher quality binding posts.

Those binding posts are pricey. They do look nice though. Will have to order a short kit from you when you get them together since you have gone through all the trouble. Thanks again.

Looks great. I want to know where you got that snazzy tape.

Hmm, I have an issue with about the same setup.

I currently do not use Zener diods, but I have them on inbound so I will confirm/deny if this fixes it.
Now, I have TWO x 2 Server supplies in series.
Both of them are modified so both cases are grounded and DC side is floating.
(DL580G2 power supplies)

Both works great, all readings are good.

But, When PS1 is connected, in series, to the same AC outlet as PS2, it damage the USB output from the Charger.

Yep, strange one but since I'm working on the EOS Control suite, these kind of stuff falls in my laps.

• If I disconnect the PS1 from the AC outlet, the communication from the charger resume without errors.
  
• If I ungrounded one of the PS1's power supply on AC side, the communication is restored.
  
• If I uncouple the PS1 so they are not in series, the communication is restored.

(Note, the Charger is NOT running off the PS1, it's running off PS2)

This is not a wicked single instance where my PS is one of the kind, having other users with the EOS suite that has exact same issue.

I will see if I can measure exactly what's going on, must be some ripple somewhere as it affects another PS on same AC outlet.

Edit;
I should add that I at first thought it was something at first that the computer was connected to same circuit breaker, but same effect if I use a laptop without AC power attached.
So it's the actual charger that gets affected for sure.

Mr Mel,
Not quite sure I have completely understood what you are saying, but if I have, then it is likely that you are correct and it is a ripple problem because the DC outputs are floating. Can you not ground the -ve of the composite 24V output?
There are "Y" capacitors on the input and interwinding capacity on the transformer so that the ouput is likely to be flying about in common mode, ie both OV and 24V terminations going up and down together at high frequency. There will also be some differential noise to confuse it further and scramble data transmission.

Wayne

I wonder if you could run 4 of these in series/parallel to get more power at 24V?

MrMel,

I agree with Wayne, the first thing I would do is ground the dc- for 24v and see if that fixes it. If it doesn't then you probably have a combination of things going on. It could be that the power supplies are producing dirty DC in such a way where it is feeding back to AC and causing problems on the neighboring power supply. If that is the case then the power supply you have probably doesn't like being in series. Another problem could be the input filtering on the charger or it being pretty picking about the serial input levels.

I know that on my powerlab 8 it shows the voltage going up when the power supplies are loaded. FMA thinks the issue is that as the power supplies oscillate against the PL8 and it's own input oscillation which causes overrun which the PL8 can see when it samples the input voltage during quiet times. They didn't seem concerned about it and nor am I.

Anyway, I think it may be time to buy an o-scope. That would really tell me what is going on. Perhaps later this month.

schu

Steve,

I have no idea how that would work. I haven't tested that. I'll have more power supplies later this week so perhaps I can look into it.

schu

Grounding semi-helped, now I got no contact with the charger, but no garbage which I had before grounding.

I got a scope so I will check out how it looks compared to my "working one"

Originally Posted by steve1814

I wonder if you could run 4 of these in series/parallel to get more power at 24V?

I've done precisely this with 4 IBM 235's and had no issue whatsoever.

As long as the PSU's are designed to be used in a redundant parallel configuration, there's practical no reason why multiples cannot be used in a parallel / serial configuration to gain more power provided adequate provisions are employed to ensure that DC returns are isolated from case and AC returns.

Mark