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Re: Jaguar Meltdown
This may not be debris. This year with the slippery wheels, a jag can go from full forward to full reverse in a very short period of time both electrically and mechanically. This could be a problem with them dealing with back EMF. Does any body know what FET they are using? While modern FETs are tough, the intrinsic diode can be the weak point and when the diode blows FETs look allot like the picture. Didn't the victors have a separate diode to deal with back EMF? Does the Jag? I've noticed that some high power drives that can handle these surges use a special type of MOV to soak up and dissipate the energy from a rapid reversal. Other speed controllers that are used for battle bots warn to allow a time period before applying a reversal. Also, the jags thermal sensing is not part of the FETs and can not react real fast. There are drives that are based on intelligent high side switches that have current and thermal protection built in to the package. It's a more difficult design when using multiple FETS per leg of the H bridge, however they are much tougher. Our team is using a joystick rate of change filter that gives a pronounce decay and ramping up when the driver changes direction rapidly. If jags have the back EMF problem, our filter should help allot.
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