# quiet controller



## ga2500ev (Apr 20, 2008)

I'll leave others to answer the question about a specific controller. However, I do have two points to make.

1) The reason that the 1231 shifts frequencies is because at low PWM in certain circumstances, the motor will over current and the controller will shut down. So the lower frequency PWM gives the system an opportunity to recover from a pulse before the next one runs right on top of it.

2) A programming note: There is now a separate controller forum. You question is perfect for it. So don't be surprised if one of the mods transfers your thread there.

ga2500ev


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## TX_Dj (Jul 25, 2008)

Have you had the opportunity to experience a curtis controller in action first hand? If not, contact your local EV club or find someone near you on evalbum who has one.

I find that videos of people's EVs with Curtis controllers seem to sound louder (to me at least) than in person. I've noticed the whine seems to only last as long as you're just starting to move, or trying to move very slowly. If you get on it, it only makes that noise for a split second. 

YMMV.

I am most likely to use a Curtis controller in my truck, but I am reserving that decision until purchase, which will be a while yet.

However, if I do choose something such as a Logisystems or other quieter controller, I will be installing a "quiet" alert sound for grabbing people's attention.


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## Dr. Bill (Oct 17, 2008)

Hi.....Other than noise can someone expound on the difference that zilla or zapi or anyone's controller will make in an ev other than lighten the load thru your pocketbook........Doc


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## ClintK (Apr 27, 2008)

Dr. Bill said:


> Hi.....Other than noise can someone expound on the difference that zilla or zapi or anyone's controller will make in an ev other than lighten the load thru your pocketbook........Doc


I think Zilla is most notable for their great quality, high amperage, and high cost.

Kelly is known for their questionable quality, questionable power ratings, and low cost.

Curtis is known for their good quality, widespread (and long) usage, reasonable prices, and noise at low speeds.

I haven't heard anything especially good or bad about Logisystems.

I've been thinking about buying a controller from ElectroCraft http://pages.interlog.com/~dgv/dc.html but they aren't well known.

Not sure about Zapi.


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## grayballs (Aug 27, 2008)

Having just discovered this forum, although I'm not new to ev's, take this for what it's worth.
My general experience has been that most of the discussion about about Curtis noise is from people that have not experienced it except possibly on video. I have no experience with the 1231's but have done 5 builds (all motorcycles and tadpoles) with the Curtis' 1209 B series. The noise issue is generally a non issue. The thing I have noticed is with the lack of engine noise or tailpipe noise one becomes aware of the other things, bearing and motor whine, chain or belt noise, street noise, controller and such. Having divorced yourself from $2.50 - $3.50 gas will more than make up for any discomfort you feel otherwise. 
The curtis controllers are well made, priced fairly and dependable, and if you're going to be working with power in the 400a + range dependability is first on your list.


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## dimitri (May 16, 2008)

When I was in research phase of my EV project I was obsessed about Curtis noise for a while, but after few responses of experienced owners I decided to go with Curtis anyway. I can tell you that whole noise thing turned out to be a non issue. It doesn't last more than 2-3 seconds even at slow speeds, and even then its more noticeable from inside the car than by people outside. I was surprised to find that it doesn't even turn heads when I pass by bunch of people on a sidewalk while "whining".

just my $0.02


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