Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Construction > Boatbuilding > Electrical Systems
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-23-2008, 01:46 PM
missinginaction missinginaction is offline
Senior Member
 
Join Date: Aug 2007
Rep: 361 Posts: 297
Location: new york
Induction type amp meter

Hi Folks,

Well, it's almost time to thaw out up here in New York and get back to work on my Silverton restoration project. One of the first projects is to rewire the electrical system and install new gauges in the helm that I built last year.

I found a web site the other day that featured an amp meter that uses induction to measure current rather than the typical shunt arrangement. It looks pretty slick to me, and I was curious as to weather anyone out there had any experience with these meters. I'll post the link to the instruction sheet for the meter below.

Regards, MIA


http://www.wemausa.com/specification...structions.pdf
Reply With Quote
  #2  
Old 02-23-2008, 03:18 PM
CDK's Avatar
CDK CDK is offline
experimental engineer
 
Join Date: Aug 2007
Rep: 1316 Posts: 2,145
Location: Adriatic sea
That type of ammeter is widely used in the industry because the measurement is non-invasive. Disadvantage is that you cannot measure small currents and wires must not be close together because the field around adjacent wires influences the meter readings.
Reply With Quote
  #3  
Old 02-23-2008, 04:58 PM
Guest625101138 Guest625101138 is offline
Previous Member
 
Join Date: Jan 2007
Rep: 0 Posts: 0
Just a fine point but DC meters do not use induction. They rely on the Hall effect:
http://en.wikipedia.org/wiki/Hall_effect
ttp://www.powerstream.com/DC-clamp.htm

Down the page of the second link you will see the sort of range and accuracy possible. I doubt that you need better accuracy or smaller range.

If your unit is from a reputable supplier it should be fine. Even if not accurate in absolute terms it will give good relative reading.

I was tempted to buy one of these meters for my electric boat application and may still do. At present I only go to 10A so I purchased an AUD16 meter from Tandy. These have an internal shunt. You can get good shunts from the electric car places that are used for high current systems but then you have all the hassle of lugs and terminals. Not difficult if you are wiring from scratch but a real pain just to get a current reading.

Rick W.
Reply With Quote
  #4  
Old 02-24-2008, 01:08 PM
missinginaction missinginaction is offline
Senior Member
 
Join Date: Aug 2007
Rep: 361 Posts: 297
Location: new york
Thanks much to CDK and especially Rick Willoughby for the insight and education on the Hall Effect. I followed your links and learned something new today!

Appreciate the education. I'm going to give that Hall Effect meter a go.

MIA
Reply With Quote
  #5  
Old 04-10-2008, 12:37 AM
pila pila is offline
Junior Member
 
Join Date: Mar 2008
Rep: 10 Posts: 17
Location: michigan
Those type of ammeters were used in the 30s by Ford. They seemed to work OK. The gas gauge on my Dad's 34 Ford didn't work though. It had a glass column like a site gauge, never did know how it was supposed to work.

Some of the older airplanes I work on have the shunted ammeters. No heavy wire to the panel, and weight is a big factor.
Reply With Quote
  #6  
Old 04-21-2008, 05:49 AM
thudpucker's Avatar
thudpucker thudpucker is offline
Senior Member
 
Join Date: Jul 2007
Rep: 330 Posts: 703
Location: Al.
I had one (in the 50's) that was used in trouble shooting starters. I yoked the source to the starter and would measure several hundred amp's the starter would draw. It was also sensative enough to measure the Generator or Alternator supply.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
International 3 meter rapscallion Multihulls 12 05-30-2008 05:52 AM
8 meter trimaran design rapscallion Multihulls 0 08-09-2007 10:47 PM
5.5 Meter Alixander Beck Sailboats 1 09-07-2005 10:40 PM
Prop/Impeller? & Hull Type? Mad Scientist Powerboats 14 06-20-2005 08:37 PM
Resin INDUCTION for foils? seamonkey Fiberglass and Composite Boat Building 2 05-04-2005 03:36 PM


All times are GMT -5. The time now is 03:17 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net