ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (CoolWill), 250 guests, and 13 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#185862 04/02/09 12:15 AM
Joined: Oct 2005
Posts: 141
L
Member
The webmaster of a small home plating website claims to use multiple variable voltage/amperage power supplies, he says he wires them up in a "master and slave configuration", because we need current more than voltage I'm assuming he's somehow wiring multiple supplies in parallel. Opinions on this?

So the power supply has 120 volts going in and two terminals supplying 12 - whatever volt DC. I obviously know how to wire batteries in parallel but how could power supplies be wired in parallel? I mean I cant take the 12 VDC + from the first PS and wire that to the 120v input, what am I missing?

He claims to be using 3 70A power supplies to provide him with 210A.

Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

Joined: Nov 2005
Posts: 827
Likes: 1
J
Member
You can usually parallel the outputs of DC supplies but might have issues with different types. Getting the current shared equally is one. A bummer with high current supplies like you mentioned, is that it takes a ridiculous amount of capacitance to filter the output. This is especially true of a linear supply with 120Hz ripple. The 3 supplies would do well for you if they were fed from three phases and each had full wave outputs. The ripple frequency would increase but the ripple amplitude would be greatly reduced.
Joe

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
Way back in the olden days when we had massive power supplies in computers they ganged several supplies together with short pieces of nichrome wire that acted as a resistor to balance the outputs.


Greg Fretwell

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5