Quote:
Originally posted by bigben2k
-add a 3 amp fuse (or 2.5 amps)
-add a 10'000 uF cap
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I'd strongly suggest adding the diode as flyingass suggested. It will clamp very high frequency voltage spikes that a big electrolytic capacitor won't suppess effectively.
I'm not so sure the high value electrolytic cap is of much value since it's a brush type motor. Something like a 0.1 uF film or ceramic capacitor might be better.
I'd consider leaving the fuse out if you've got a good PSU.
The purpose of the fuse is primarily to prevent excessive current draw if the the impeller is prevented from spinning. (Locked rotor current.) In that event it might be better to allow the current draw of the pump to overload the 12V rail and cause the PSU to shutdown. (Very iffy protection mechanism, I know, but if the fuse ever does its job, you've got other issues as well.)
If someone wants to send me one of these, (and a money order to pay for return shipment) I'll check the transients it puts on the 12V rail and find out what works well for suppressing them.
Edit: I'll post scope pictures as well.