On Wed, 2008-01-09 at 22:32 -0800, Rafael Skodlar wrote: > Ouch! > > > There is a burned trace above the top part, and I measured zero Ohms in > > both directions on both parts. > > > > > What about other traces? How many layers are there in this board?
Just two layers. > I would check other components, SCRs especially. Diodes were there to > protect other parts and probably failed to do so at some point. > > Remove the board and look at it with strong light behind it to see any > other damage if the board is multilayer. I did remove the board. The only damage I could find was basically the through hole by the top diode. > > Thanks > Good luck, I used the board to run a motor with a field winding that drew enough current to blow out a mains filter. (I used the filter because it had a switch and connectors.) So I removed the filter and tried another motor without a field winding and the trace blew. The diodes basically rectify the mains to supply the field F+. I checked the filter and it was rated for 1A, so I am thinking, that the field over-current damaged the diodes which allowed additional current to blow out the filter, but not enough to blow the trace. When I bypassed the filter, I re-energized the damaged diodes which then blew the trace. I guess I'll find out if I am right after I replace the parts and try again. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
