LM3914 + Current Sensor

Thread Starter

Pencil

Joined Dec 8, 2009
272
Hello everyone,

I have tried to design a circuit to monitor
current (DC) in a wire using a Honeywell CSLA2CD
sensor and an LM3914. I would appreciate the effort
if I could get some advice/critique on my work so far.
I have attached the schematic and relevant datasheets
for convenience. My notes are included with the drawing.

Thanks for looking.

P.S. Automotive application is mentioned in "Notes" section.
I am aware of the recent "discussion" regarding these
types of circuits and feel it is appropriate. (It is non-
invasive, does not penetrate any bulkheads, and will
not alter any system functions).
 

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hgmjr

Joined Jan 28, 2005
9,027
Can you provide a brief detailed description of what you are trying to do with the circuit beyond the fact that you are looking to monitor the current? What are the various limits you are looking for in terms of amps in the line being monitored?

hgmjr
 
Last edited:

Thread Starter

Pencil

Joined Dec 8, 2009
272
Can you provide a brief detailed description of what you are trying to do with the circuit beyond the fact that you are looking to monitor the current? What are the various limits you are looking for in terms of amps in the line being monitored?
Brief description: Mostly just building for fun/practice/learning. As far
as the automotive concerns, I have an old truck (1972) I am always
working on and thought I'd add a little current monitor to the 2-speed
axle (electric) to give an indication if it ever "hung-up" when shifting.
I wanted to do this in the least invasive way, hence using a sensor
that I wouldn't have to insert anything to the line. I mentioned the auto-
motive aspect as a "full-disclosure" kind of statement, if it don't work
for its intended purpose I'll change it up, run it off some rechargeable
batteries and play with it somewhere else.

Various limits:
Supply voltage: 12.5-16V
Monitored Load : 0-16A (this may need adjusted based on future findings)
Load for full scale: 15.3A (see above)
1st LED lights @ 0A
I haven't checked the exact current requirements as of yet, but I do know
that the circuit is running on a 20A fuse.


Thanks for responding. I hope this is acceptable.
 
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