Measuring Current With WCS 1800 (35 A DC Current Max)

Thread Starter

TMK3252

Joined Nov 30, 2016
13
I am trying to measure a DC Current of 10A (My requirement) with WCS 1800 which is attached below. when zero current passes through it it is giving me 2.45V as Aout(oscilloscope output). when i keep increasing the current i got the values given under (current and A out).

but when i increasing the current more than 5.5 a the LED which is on the wcs1800 board goes off. what does it indicate.

i dont know what does the pot do here?

need help in this.

1707714453182.png
 
Last edited:

tonyStewart

Joined May 8, 2012
131
What does it mean?

It means your circuit board is missing links to verify what it should do, such as amplify 66mV/A from the Hall sensor and not just invert it starting at ~5V/2. Perhaps it is missing parts. It looks like it is missing parts.
Most likely the pot would control gain or offset but not both.

Why don't you investigate further? Then get back to us with answers.

1707722057428.png
 

tonyStewart

Joined May 8, 2012
131
What does it mean?

It means your circuit board is missing links to verify what it should do, such as amplify 66mV/A from the Hall sensor and not just invert it starting at ~5V/2. Perhaps it is missing parts. It looks like it is missing parts.
Most likely the pot would control gain or offset but not both.

Why don't you investigate further? Then get back to us with answers.

View attachment 315014
It should not be inverting and have gain 1+Rf/Rin

Trace the schematic to find the fault and show your Vcc to Gnd
It should have +ve gain of 2.16 with trim by pot
if Vout=5V @35A
1707743527549.png
 

tonyStewart

Joined May 8, 2012
131
The board uses the pot as a threshold comparator but the Hall sensor seems to be Vcc/2-Aout and hence was 71 mV/A as I computed in spreadsheet for your Vcc near 5V. It has a sensitivity that is Vcc sensitive.

You must add your own signal conditioner amplifier to Aout using the datasheet or calibrate & convert in S/W. This board does not do what you expect.
1707746761097.png

https://www.winson.com.tw/uploads/images/WCS1800.pdf

1707746221657.png
 
Last edited:

MisterBill2

Joined Jan 23, 2018
18,442
The circuit looks a bit like a 4-20 mA driver circuit, but that is just a guess.
And I wonder if the current is passing thru in the correct direction.
AND it may be that the module range is zero to 5 amps.
 
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