current sensing using soic chip

mosquito56

I am trying to read the charge- discharge rate of a battery. I have found the SENSOR CURRENT 20A 5V BI 8-SOIC at digikey. The question is connecting the chip. I don't see how you connect one of these to the battery. A 20amp current requires a large wire. Am I missing something here?
· Do I run all the current thru this chip?
· I see something called a toroid sensor with built in amp, but cannot find a part number anywhere. Any ideas?

Thanx
Don

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Post Edited (mosquito56) : 8/17/2009 3:26:13 PM GMT

W9GFO

The Allegro 620-1190-2-ND is the type where you run the current right through the chip, two pins for current in, two pins for current out. If you jump up to the 50 amp, 620-1190-2-ND, the chip style changes to have large lugs to connect power. Other types of open loop hall current sensors have a hole through them where you pass the buss bar or wire that you want to sense.

There are also current sensors chips that measure the voltage drop across a shunt resistor.

Rich H

mosquito56

Yes, hole thru them is the part number I can't find.

Thanx

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·······

······· "What do you mean, it doesn't have any tubes?"
······· "No such thing as a dumb question" unless it's on the internet
········

W9GFO

Tamura makes some like that as does Honeywell. It seems that the hole-through kind are all higher amps. My quick search turned up 45 amps as being the lowest value with the hole.

Rich H

mosquito56

I think I have it figured out , thanks for your help

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·······

······· "What do you mean, it doesn't have any tubes?"
······· "No such thing as a dumb question" unless it's on the internet
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