How to test a hall effect device

[madderscience]

OK not directly EV related but you could imagine a connection, so...

Does anybody know of a simple way to verify the correct functioning of a hall effect device?  My welder has crapped out and the diagnostics that the manufacturer has asked me to run suggest that the weld-current-sensing hall effect device has failed.   However I would like to verify the failure with the device out-of-circuit first.   

Test circuit schematics would be awesome.

Ideas?

[leitmotif]

Brian
Ideas yup.

First -- what are specs on sensor?  Amps in weld lead circut vs volt (current?) output.
Max amps it can sense.  Does it have a power supply - if so what ie AC / DC volts etc

Send circuit diagram of the welder & mfr diagnostics (are these the ones in the back of the owner manual?) and I can help you.

Dan Bentler

[madderscience]

Its an LEM HAS 200-S.    supply voltage +-15v, output 0v reference and +-4v for +-200A of current flowing.

http://parts.digikey.com/1/parts/945568-transducer-currnt-open-loop-200a-has-200-s.html

I verified (in-welder) that the supply voltage is good (30v) and the output just isn't there, so I ordered off for a new one.

The hall effect device costs $25, a new control board (the other thing that could be horked) costs $650.  and I'm pretty convinced
its the hall device now anyway.

after looking up the specs (once I realized it was not a proprietary part) I now know I could just stick it on the starting battery cable for my truck and wire up +-15v and see what happens on the output when I crank over the engine.    (its a little to small to stick it on one of my EV's battery cables, but it would fit a normal starting battery cable)

On an aside a unit similar to this one might make a good pickup for a watt-hour meter and ammeter or what have you in an EV.  total isolation.  Is that what the fancier things use (e-meter, paktraker, etc) or do they use a shunt?

Thanks!

 

[leitmotif]

Ok now we know what we got.

I dont think I would test it on the truck engine.  It is only a 200 amp unit.  Truck starter may (will?) draw more and may blow up the hall effect unit - find out what peak current is before the truck trick.  Would be a good is it broke test tho.

What I had in mind is something a little more scientific ie test hall effect with known load ie battery and couple headlights say 15 or 30 amp.  Read the output voltage (are you sure output is 0 to 4 for corresponding 0 - 200 amp?)).

I have not messed around with Hall effect.  I think you are right they give an isolated output wheras shunts do not.  I would choose Hall effect for current monitoring on a vehicle main battery.

What kind of welder do you have MIG TIG SMAW etc??  Possible to stick a 1.5 VDC battery in to substitute for Hall effect and stick output leads in a bucket of water baking soda mix for a load.

Maybe for only $25 easiest and cheapest to get new one.  If old one OK then you have a spare or one you can use on something else.

Checked factory web page yes you can run it up to peak of 30K amp - truck go no go test would be OK.

Dan Bentler
Dan Bentler