I need to pass 25A through the PCB, in order to use a SOICN 8 hall sensor to measure the current through a battery pack of 24V, 25A. I will make the trace for 30A.

1. According to the online calculators I need a 16.4mm top copper or bottom coppr trace and a 43mm internal layer trace, are the mm ok?
2. Which layer is prefered (I guess top)?
3. What will happen is I connect 3 traces of 5.5mm each instead (looks like a good option to me)?

 

hi,
The other point you need to consider is the copper weight/ft sqr. [ 0.5oz thru 3 oz]
Look at this link.
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj8y-_mpLnaAhWOWsAKHesCBdkQFggnMAA&url=http://www.4pcb.com/trace-width-calculator.html&usg=AOvVaw1DlLVZH-a3Yt5pahI-Z8io

Clip:
The original graphs that this tool is based on (published in IPC-2221) only cover up to 35 Amps, up to 0.4 inches of trace width, from 10 to 100 degrees C of temperature rise, and copper of 0.5 to 3 ounces per square foot.

E

 

Its this one: 2oz/ft2.

 

I recommend using saturn pcb toolkit, it calculates the temperature rise of a pcb trase, current capability of vias and much more.

 

Remember, the main limitation is temperature. If there is air flow over it or the use is intermittent, then the ratings go up considerably.

 

You will save yourself a lot of grief if you use busbar (or appropriately sized solid copper wire) for most of the high current runs. You can solder solid copper wire onto the printed conductor to get the effect of a busbar.

 

It will be in a battery bank of 2 batteries by 2V in a metal frame. It will on top, between the battery top and the metal frame top. The battery bank will be sitting while charging and moving while the AGV is moving. I guess there can be a whole in the metal frame, for the air flow.

 

You will save yourself a lot of grief if you use busbar (or appropriately sized solid copper wire) for most of the high current runs. You can solder solid copper wire onto the printed conductor to get the effect of a busbar.

I was intending to do this before, but the requirements can get harder and harder. Like putting a Hall sensor to measure the current. I do not know if I can just solder wires to the hall sensor on the PCB? In this case, how big should the pads be or any other requirements? The hall sensor is Alegro ACS724 with already made pads on a SOICN 8 package.

EDIT: Plus sooner or later I will need a 30A trace, so it is good to know this.

 

I would solder the hall sensor to the largest pads you can make without shorting, then bring the solid copper wire and as wide-as-you-can-make-it traces right up to the pads.

 

There is also an option to use a aluminum PCB v. FR4 :https://www.element14.com/community...pcb-heat-transfer-basics-for-led-applications

 

This is a different sensor. If I buy it with a board attached, it will look like this:
https://coolcomponents.co.uk/products/acs715-current-sensor-breakout

This is what I intended to use originally:
https://www.allegromicro.com/~/medi...hash=E88AFC2FBE3927EC6040711062525F41BABD60B4
Is it possible to mount the whole board on my PCB?

Circuit is shown below:

 

Hello,

Perhaps this EEVblog video might give you some ideas:

Or have a look at this page:
http://www.epectec.com/articles/heavy-copper-pcb-design.html

Bertus

 

I found something interesting, that I do not know if I should believe.
It gives the track width and cross section (area of the wire). Unfortunately it also states that the maximum rated current is 25A and not 30. This is for the finder 66.22 relay or 66.82. The datasheet is in the link:
https://gfinder.findernet.com/public/attachments/66/EN/S66EN.pdf

The rest is in the picture.

 

Thank you all for your help in all threads!