Shop our Airplanes Products Drone Products Sales
Thread Tools
Old Jan 30, 2013, 01:39 AM
still4given is offline
Find More Posts by still4given
Sky Pilot
still4given's Avatar
Yeah, mine's bare-bones. No covering, feet or anything. No 12V connectors, only 24V with like I said, a Deans T-connector. I may stick some feet on it if that seems necessary when I get it to the field. I did make a Y-cord for the supply. I had a few power cords so I cut two of them and soldered into a Y. I didn't count that time in the hour since I did that after I posted. No extra fan grill either. Folks will have to keep their fingers out of there.
Sign up now
to remove ads between posts
Old Jan 31, 2013, 11:43 PM
MaxdOut is offline
Find More Posts by MaxdOut
Registered User
I read this entire thread and probably missed it, but what happens if DC ground is floated on both units in a 24volt configuration?
Old Feb 01, 2013, 12:01 AM
still4given is offline
Find More Posts by still4given
Sky Pilot
still4given's Avatar
Some seem to think it is a problem. I don't, however, being lazy, I only did the one. You don't have to open up the case if you don't float the ground.
Old Feb 01, 2013, 12:08 AM
JohnathanSwift is offline
Find More Posts by JohnathanSwift
Suspended Account
Danger will Robinson!
Old Feb 01, 2013, 12:10 AM
still4given is offline
Find More Posts by still4given
Sky Pilot
still4given's Avatar
Nonsense, have you tried it?
Old Feb 01, 2013, 05:59 AM
feathermerchant is offline
Find More Posts by feathermerchant
Use the 4S Luke
feathermerchant's Avatar
Isolating both power supply outputs will increase the possibility that high voltage can appear on the output should you have an internal fault in a power supply. In addition, if you connect your charger to your PC which may be grounded, the fact that the power supply output is floating may cause damage.
Old Feb 01, 2013, 06:59 AM
rchelijc is offline
Find More Posts by rchelijc
Pro beginner
rchelijc's Avatar
Quote:
Originally Posted by feathermerchant View Post
Isolating both power supply outputs will increase the possibility that high voltage can appear on the output should you have an internal fault in a power supply.
Yes, possible. Multiple threads discussing this everywhere. Basically, if the numbers are correct, you're more likely to be hurt by an out-of-control RC bird.

Quote:
Originally Posted by feathermerchant View Post
In addition, if you connect your charger to your PC which may be grounded, the fact that the power supply output is floating may cause damage.
This is new to me. On the surface, the only way this can happen is somehow the zero entire unit builds up enough charge that the zero is in the low hundreds of volts potential diff with earth, that instantaneously zaps when connected to earth through your cable. Kinda like a static discharge.
Old Feb 01, 2013, 08:47 AM
feathermerchant is offline
Find More Posts by feathermerchant
Use the 4S Luke
feathermerchant's Avatar
Remember that there is a transformer in the power supply. It just operates at something like 20kHz instead of 60Hz. A transformer can short primary to secondary making for high voltage on the output side.
Old Feb 01, 2013, 08:50 AM
JohnathanSwift is offline
Find More Posts by JohnathanSwift
Suspended Account
Danger.....
Old Feb 01, 2013, 09:07 AM
MaxdOut is offline
Find More Posts by MaxdOut
Registered User
Ok, kinda thought it would be a bad idea, just wanted to make sure.
Old Feb 01, 2013, 10:57 AM
still4given is offline
Find More Posts by still4given
Sky Pilot
still4given's Avatar
Quote:
Originally Posted by feathermerchant View Post
Remember that there is a transformer in the power supply. It just operates at something like 20kHz instead of 60Hz. A transformer can short primary to secondary making for high voltage on the output side.
Have you ever seen this happen? Maybe if you were using a toroidal transformer and you somehow dropped it and was able to scuff the coated wires but I have never had a transformer short from the high side to the low side. Even if it did, having 120v on the output would still be there even if the grounds were connected. Nothing would happen unless you shorted them. All they would do is burn out your charger. The only time it might be a danger to you is if you grabbed both leads and even then I doubt the main fuse would pop unless you had it plugged into a ground fault circuit. Having the ground lifted in one of the units can still cause the scenario you worry about as that side could still do that.

Anyway, it is easier to just do one so it is probably a moot point.
Last edited by still4given; Feb 01, 2013 at 06:57 PM.
Old Feb 01, 2013, 11:11 AM
JohnathanSwift is offline
Find More Posts by JohnathanSwift
Suspended Account
Moot I reckon. Good pun!
Old Feb 01, 2013, 06:36 PM
rchelijc is offline
Find More Posts by rchelijc
Pro beginner
rchelijc's Avatar
Quote:
Originally Posted by feathermerchant View Post
Remember that there is a transformer in the power supply. It just operates at something like 20kHz instead of 60Hz. A transformer can short primary to secondary making for high voltage on the output side.
These are datacenter PSU's - on some of the most commonly used equipment in the world. 240/110V to output is bad news for these and we would surely hear a lot about them since this is a definite outage and data loss scenario.
Old Feb 01, 2013, 07:12 PM
JohnathanSwift is offline
Find More Posts by JohnathanSwift
Suspended Account
Hi, I'm Reddi Killowatt, and I'm here to help you....
Old Feb 01, 2013, 07:15 PM
still4given is offline
Find More Posts by still4given
Sky Pilot
still4given's Avatar
Took my PSU to the field today to show off to my friends. One of the Pattern guys picks it up and says "Hey this is pretty light. My power supply weighs a lot more, how many amps is it?" I say it's 47 amp and he says "Oh mine is 70amp." I say, "How are you powering that, because mine uses up a 15 amp household circuit? He says it's not a problem so I ask how many volts are you putting out and he says 12V. Ah I say, mine is 25V. HE asks how that matters and I do the math for him. 12V*70A=840W. 25V*47A=1175W. Top that with the fact that your charger will run much cooler on the higher voltage since it doesn't have to work so hard to convert 25V to the 38V his 10S packs are using and he's like "Dude, build me one!". I tried to talk him into buying one from one of you guys who builds these things for sale but says he wants a bare bones one exactly like mine. Looks like I have to build another.

Blessings, Terry


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Flydumini Frame Thread and Build Hints/Help nasgul Multirotor Talk 216 Sep 28, 2013 05:58 PM
Discussion DPS-600PB Power Supply Shuts Down wcsd106 Batteries and Chargers 3 Jun 23, 2013 07:11 PM
Mini-HowTo Tips, Tricks, Hints, Secrets & How To's to help make a build/rebuild easier... ABADGTP The Builders Workshop 37 Dec 24, 2011 12:48 PM
Discussion Sokol build tips and hints Dan the man High Performance 9 Aug 21, 2008 04:26 AM
Discussion GWS Piper Cub Build Tips & Hints? Royster Australia 111 Feb 07, 2007 04:11 PM