I've done a little research.
the current when the valve servo hitīs the stop is 780mA and the FET transistor is rated at 5A, so it looks like the transistors are burnt because of a sustained high current which, over time, heats them up so they burn.
If this is the case, then a fuse could be usefull.
I've also tried a small bulb in series, as its very low resistance when cold, at low current, but at higher current it heats up and the resistance increases, so it acts as a current limiter and you get a bonus, as the bulb will light up when the servo is drawing excess current.
The bulb I'm using, limits the max. current to 170mA which is a factor 4. This could be enough to protect the transistors of the PGM
The resistance at low current makes the servo go a little slower but I don't know if this will be a problem when running the bike.
I still need to know the running current of the servo, also the output voltages from the PGM and the schematic of the transistor circuit if anyone has it ?
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom
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