[thespindoc]

Hi Guys, My bridgeport retrofit continues to burn Gecko drives. It
happened just a few minutes ago when I powered up the machine and
computer. The powersupply was plugged in but the relay controlling
the powersupply was off. When I hit the button in the software to
turn on the relay the Gecko immediately burned as did the protecting
fuse. It always happens on the y axis when I first start up. It
never seems to happen while running the machine. This is at least the
fourth time this has occurred. Each time I think I have found the
problem but alas, no. The last time was early Feb and then again
last week. A new Gecko was installed thursday. It makes no sense
why the thing would run for a month with no trouble. It think
everything is installed correctly but there must be a powersurge from
the powersupply when the relay first turns on. Is this a possibility
and is there a way to protect from this? I use a 75v DC 15 amp unregulated powersupply with 5 amp fuses with Zener diodes across them and also have the motors grounded through a resistor to dump excess voltage when needed.

Thanks for any ideas!

Keith Clark

[balsaman]

Is the powersupply 75 volts or is the transformer 75 volts? Rectifying it with increase the voltage 140%.

If not I would look at replacing the y axis motor and cables....It's the only thing I can think of. Have you contacted Geckodrive for ideas?

Eric

[ViperTX]

I'm assuming this is a servo setup? I would tend to suspect that you have a servo that has an intermittent short, what is puzzling is why the Gecko even turns on.....check your power supply.....I bet you have an over-voltage condition that is causing the Gecko some problems....it would be nice for you to provide us with additional information....wiring, servo versus stepper, etc.

[trubleshtr]

swap motors around,leave cables as is. if it happens again you can rule out either motor or cables at least.

[lerman]

Is the Gecko set up for proper current limiting? Is it properly heatsinked (or is that heatsunk)? If it is, you shouldn't be able to burn it out. Unless you are exceeding its voltage limit.

Ken

[thespindoc]

Thanks for the suggestions. I believe it is an overvoltage problem too. At this point I am going to gut the prior retrofit and redo it myself. Then I will get back to you if I can't get it solved.

Keith