http://www.pcb7.com/what-is-the-relationship-between-the-track-width-in-a-pcb-and-maximum-current-that-can-pass-through-it.html All about PCB Fri, 10 Sep 2010 09:52:44 +0000 http://wordpress.org/?v=2.7.1 hourly 1 http://www.pcb7.com/what-is-the-relationship-between-the-track-width-in-a-pcb-and-maximum-current-that-can-pass-through-it.html/comment-page-1#comment-76 robert h Wed, 24 Jun 2009 16:29:01 +0000 http://www.pcb7.com/what-is-the-relationship-between-the-track-width-in-a-pcb-and-maximum-current-that-can-pass-through-it.html#comment-76 First look up the resistivity of copper. Measure the length of the track needed. Now calculate the cross section of the track you propose to use. Now work out the resistance of the track over its length. Now calculate the voltage drop at the current you propose it needs to carry. Now calculate the power dissipation in the track. Now, using metallurgical data, calculate the temperature increase in the track. Decide if you are happy at that temperature. If not, the power dissipation will decrease by half by doubling the width of the track (provided the current is the same). Or you can do it the easy way. Ie, use a wire bridge thick enough to handle the current you require. First look up the resistivity of copper.
Measure the length of the track needed.
Now calculate the cross section of the track you propose to use.
Now work out the resistance of the track over its length.
Now calculate the voltage drop at the current you propose it needs to carry.
Now calculate the power dissipation in the track. Now, using metallurgical data, calculate the temperature increase in the track.
Decide if you are happy at that temperature.
If not, the power dissipation will decrease by half by doubling the width of the track (provided the current is the same).
Or you can do it the easy way. Ie, use a wire bridge thick enough to handle the current you require.

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