Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[nsa66]

Hi

I am currently refurbishing my accident damaged TID tug and I am rewiring the whole thing to 12V. While attending to the motor (a Robbe 3.3:1 geared design) I noticed that I had not fitted any suppression to the motor. Now, to me that was puzzling as I was well aware of the interference problems that could arise in unsuppressed installations and I had always fitted them to previous models. As the model is now nearly 15 years old I cannot for the life in me remember any reason why I wouldn't fit the caps. The only thing I can think of is that the ESC manufacturers (Electronize) may have claimed some sort of inbuilt suppression. However, I am by no means sure whether this was the case. In the event I never suffered any problems with interference though whether by luck or judgment I am not certain.

If possible I would like to avoid having to fit the capacitors due to tricky access to the terminals/casing but neither do I wish to bury the thing under a bird's nest of cables and have to pull everything out at a later date cos everything is twitching, so I was wondering if anyone else has any ideas about this situation. How effective would it be to simply add a single capacitor across the terminals at the ESC end of the lead (and, if so, what value)?

Any advice gratefully received.

[Subculture]

I very much doubt the Electronize controller has built in suppression. Can't imagine how it would be effective unless the controller was bolted directly to the back of the motor.

Some motors (e.g. Graupner Speed series) come with suppression caps already mounted inside the motor between the brushes and the terminals, although it's usually a good idea to wire a third capacitor across the terminals of a higher capacitance for optimum suppression.

If you're using 2.4ghz equipment in your refit, then motor suppression isn't really needed.

[Netleyned]

If you're using 2.4ghz equipment in your refit, then motor suppression isn't really needed.


It's nice to be nice to the 27&40 Megabyters that still inhabit our ponds and lakes so please suppress 

Ned

[Subculture]

Will it make a difference to other boats in the near vicinity? I'd have thought any interference would be too weak to cause problems outside of the vessel concerned.

[malcolmfrary]

The idea of suppression is that it happens as close to the motor as possible, before the wiring to the motor acts as a transmitter aerial.  It is possible that the motor already has suppression fitted.  The clue is an extra wire on the tag vanishing into the motors interior.
If the setup has never interfered with itself using 27 or 40, it is unlikely to interfere with anybody else.  Still, belt, braces and piece of string on self supporting trousers...........

[nsa66]

Thanks for the advice guys. I've decided that 15 mins of fiddling now might save an awful lot of hassle in a few weeks time so I've fitted the caps. I'm still running 40MHz and there does not appear to be anything connected to the terminals. I am absolutely mystified as to why I didn't add the suppression in the first place. Nowadays I'd put it down to a senior moment but I can't believe I just forgot.