Go Back   AnandTech Forums > Hardware and Technology > Highly Technical

Forums
· Hardware and Technology
· CPUs and Overclocking
· Motherboards
· Video Cards and Graphics
· Memory and Storage
· Power Supplies
· Cases & Cooling
· SFF, Notebooks, Pre-Built/Barebones PCs
· Networking
· Peripherals
· General Hardware
· Highly Technical
· Computer Help
· Home Theater PCs
· Consumer Electronics
· Digital and Video Cameras
· Mobile Devices & Gadgets
· Audio/Video & Home Theater
· Software
· Software for Windows
· All Things Apple
· *nix Software
· Operating Systems
· Programming
· PC Gaming
· Console Gaming
· Distributed Computing
· Security
· Social
· Off Topic
· Politics and News
· Discussion Club
· Love and Relationships
· The Garage
· Health and Fitness
· Merchandise and Shopping
· For Sale/Trade
· Hot Deals with Free Stuff/Contests
· Black Friday 2014
· Forum Issues
· Technical Forum Issues
· Personal Forum Issues
· Suggestion Box
· Moderator Resources
· Moderator Discussions
   

Reply
 
Thread Tools
Old 01-21-2013, 03:30 PM   #1
WraithETC
Golden Member
 
WraithETC's Avatar
 
Join Date: May 2005
Location: Washington State
Posts: 1,463
Default Drawing 20 Amps for device testing

I'm creating a test system for a device that will measure amperage drawn from a 120 Vac source. The device basically passes on the power source from the wall and uses current transformers to read how much current is flowing through mains to some piece of equipment connected to it.

I'm looking for ideas on how to draw 20 Amps off the equipment outlet of the device for a small period of time (less than 5 seconds). What was done in the past was to use a couple heaters or a bunch of light bulbs in parallel, but I wanted to see if there was a more compact solution that didn't have as high of risk for break down.

I tried looking for some current shunt resistors and combinations of transformers and resistors to do this, but I couldn't find something that worked out at least off the shelf.
__________________
petercher@gmail.com <Paypal><Main email account>
Heatware: 19-0-0
http://www.heatware.com/eval.php?id=40819
WraithETC is offline   Reply With Quote
Old 01-21-2013, 04:58 PM   #2
Mark R
Diamond Member
 
Mark R's Avatar
 
Join Date: Oct 1999
Posts: 8,256
Default

Do you want something to limit current?

If so, then your best bet is either something like a set of space heater elements - to limit current to 20 A, you'd need about 2.4 kW of heating elements.

If heat is a problem, then you can use magnetic ballasts like are used in fluorescent lights, but you want higher power - so something like sodium or industrial metal halide lighting. A ballast designed to run a 1 kW sodium (or halide) lamp off a 240 V mains supply will provide about 10A of short-circuit current when connected to a 120 V supply. 2 of those in parallel will provide you with about 20 A of short-circuit current. (Note the above example needs a "reactor ballast" (common in Europe) rather than the usual US style ballast which won't work. However, you might be able to find one or two.
Mark R is offline   Reply With Quote
Old 01-21-2013, 06:40 PM   #3
FrankSchwab
Senior Member
 
Join Date: Nov 2002
Posts: 212
Default

Well, amazingly enough Dangerous Prototypes had a design up just this morning to do exactly what you're looking for:
http://dangerousprototypes.com/2013/...-current-load/
<EDIT: Never mind, that's DC only. The circuit design also only supports 7A, but 20A would be possible with minor changes>

I'd go with an electric water heater element. A 2.0KW/120V element would run about 17 Amps, and it'll be pretty rugged and pretty cheap. If you leave it bolted into a hot water tank, you could run it for hours and heat water for the sinks in the bathroom at the same time. If not, put it in a steel pipe to protect it with a fan mounted in one end to exhaust the heat, and don't run it for more than a few seconds at a time...

Last edited by FrankSchwab; 01-21-2013 at 06:43 PM.
FrankSchwab is offline   Reply With Quote
Old 01-22-2013, 02:17 PM   #4
imagoon
Diamond Member
 
imagoon's Avatar
 
Join Date: Feb 2003
Location: Chicagoland, IL
Posts: 4,710
Default

For our datacenter power system testing we have these huge heater units an wheels with fans. There are switches on it to turn on more of the elements to allow you to increase the current.
imagoon is offline   Reply With Quote
Old 01-22-2013, 03:39 PM   #5
Sheep221
Golden Member
 
Join Date: Oct 2012
Posts: 1,153
Default

Add there anything with 2400W or similar power draw.
Air compressors have high peak current, when you turn it on, it can draw 3 times higher current for few seconds.
__________________
i5-2550K/16GB HyperX/HD5670/P67 Pro3/Agility3
Sheep221 is offline   Reply With Quote
Old 01-22-2013, 04:21 PM   #6
philipma1957
Golden Member
 
Join Date: Jan 2012
Location: Howell NJ
Posts: 1,550
Default

two of these will do

http://www.newegg.com/Product/Produc...ghi-_-96101168
__________________
1)Intel i7-3770k. i5-4670
2)sapphire hd7790 , sapphire hd7970
3)samsung 4x 4gb low profile ram
4)antec ea450 seasonic 760 platinum
5)asus maximus v gene mobo asrock itx-e
6)fractal case cooler master elite 120 case.
philipma1957 is offline   Reply With Quote
Old 01-22-2013, 04:48 PM   #7
imagoon
Diamond Member
 
imagoon's Avatar
 
Join Date: Feb 2003
Location: Chicagoland, IL
Posts: 4,710
Default

http://www.sunbeltrentals.com/equipm...ry.aspx?id=s95
imagoon is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:15 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.