??? 03/03/04 11:51 Read: times |
#65866 - RE: That is not caused by a normal ESD! Responding to: ???'s previous message |
At power-on moments of monitor, these parts are also charged suddenly and will also cause these dangerous current spikes. i think this might be one source of the problem. Are there any motors or high inductive loads at your bowling 'application' which could cause heavy overvoltages on mains? It is all single phase AC motors all over the place, and these motors have no built in line filters or any single protection, could this cause overvoltage spikes? Do I need to buy line filters for these single phase AC motors with starting capacitors? Is there a reliable protection earth routing? They are all connected to earth, AC motors, monitors, MCUs. I don't know how to measure how good the earth is, do I use Megger or what to measure the earth resistance? Open a monitor and look what manufacturer has connected from mains terminals to protection earth. This can be very surprising... Varistors and small capacitors. The question is would adding transorbs and zener diodes at the vga driver side protect the chip from this transient overvoltage? mahmood |