Victor 884 problem

[Al Skierkiewicz]

Originally Posted by Gal Longin

we were driving our robot and all off the sudden , the victor made a weird ticking sound and a spark came out of it and we smelled something burnt.

after we turned off the robot we tried to re-activate the victor it didn't work.
we opened it up and inside we saw two weird things:

1) the big capacitor in the middle of the victor was marked with a big red X sign .
2) on the board inside the victor there was written :" victor 883 rev F" and not victor 884.

Gal,
If you check the Victor again you will likely find that there is some damage to one of the 12 power FETs. (like the side is blown off or there is a big crack in the case.) Snapping and sparks are often caused by the FETs giving their lives so that the circuit breakers can be saved. If this is the case, there are a couple of causes for this. Most common is shavings inside, followed by high current draws on the motors due to things like turning in tank mode on carpet, driving at high speed into a stationary object, fan failure or rapid forward and backward motion. In some cases, a piece of conductive material falls down across the tabs of the FETs, shorting them out.
If the capacitor had failed, you would see the bottom of the case blown out, obvious liquid on the circuit board underneath the cap, distended case or a combination of all three. I believe that the upgrade from 883 to 884 installed better FETs in the output. This gave the controller higher output current specs and lower series resistance.
ed. IFI also lists the change in default deadband as a change. This has been troublesome for the precision of the pots inside most joysticks. With the increased deadband, there should be less problems with joysticks not returning to "center" resistance on the internal pots.

[Sparks333]

Originally Posted by Al Skierkiewicz

Snapping and sparks are often caused by the FETs giving their lives so that the circuit breakers can be saved.

Those selfless FETs... *sob*

Sparks