Trolling Motor Speed Controls

RidgeRunner · #1 03-23-2012, 08:04 AM

Motor Guide 24V bow mount trolling motor on the flats boat. Circa 1996. It was purchased as a wireless remote control unit and converted to a hand model after multiple failures. It now has a bad circuit board in the head which is no longer available. When I isolate the wires to the motor itself I get high speed with 24V and approx half that with 12V.

Electric motor is rated at 33A so I would need a 500 to 750 watt speed controller. The factory used a printed board they labeled "MOSFET" to vary the voltage to the motor. I do understand what a Mosfet is but not at all sure of the architecture of the board nor how to repair it.
I am not an electrical engineer, but for well short of another $1000 bucks (replacement cost) I think I will find something that will work;-) Motor doesn't have 20 hours of use because it is always broke when I go to use it...

Questions--
1. Can a pulse/wave modulator be used to control speed?
If so what are the disadvantages?

I assume MOSFET is very efficient and suspect (from all the advertising)full analog controls to be harder on the batteries. BUT I may be able to adapt a DC motor contol out of a electric scooter. They have some real inexpensive variable speed controls available. Some come complete with twist grip (POT or Hall Effect) that would be an easy adapt to the hand control. Some are rated for water too.

2. Full digital conversion? Is it possible, what would it set me back if so?

Again, I am looking to stay cheap, this motor rarely gets used. As it is now I have a high and low. I can live with that but would prefer variable speed. Thanks in advance for any help/opinions. Type slow, I'm blonde....

RidgeRunner · #2 03-23-2012, 10:32 AM

Thinking about something like this.. http://www.bakatronics.com/shop/item.aspx?itemid=856

RidgeRunner · #3 03-25-2012, 12:00 PM

Crickets-chirping.jpg

OK, I will go it alone. I am sure it will work. I will update with my findings..

reelapeelin · #4 03-25-2012, 01:59 PM

What if you find a simple reostat in the spec range?...that should give you the full range of control from hi to low...the Minn Kotas we use had speeds 1-10 and some guy came up w/a control box w/a reostat that gave infinite variable speed...it was a wired unit and worked very well for back then...I was about to buy one when the new Co-Pilot came out...couldn't resist.

RidgeRunner · #5 03-26-2012, 12:27 PM

You reckon I can get an I-phone ap to do this?? HEEHee Haa Haa..

reelapeelin · #6 03-26-2012, 03:28 PM

Quote:

Originally Posted by RidgeRunner

You reckon I can get an I-phone ap to do this?? HEEHee Haa Haa..

Heck they'll do everything else...Good talkin' to you...did the scooter switch work?...

RidgeRunner · #7 03-26-2012, 05:11 PM

Still looking at it. If I paid myself a nickel an hour for the research time I coulda bought a new one already. I think Kelly Controls is gonna be the answer to my dilemma.
http://kellycontroller.com/kds241001...ller-p-73.html

Waiting on a response from Steven Li on a few issues like the momentary on and any additional resistors/flux capacitors that I may need. Looks good so far. I think the throttle is gonna be a slam dunk factory type retro-fit. Nice because I am not sure how salt-proof they are. At $19 I don't see it being a big problem. The control unit may need to be mounted in the semi-dry hatch directly under the motor. Might need to get rid of the foot switch too. I'll conjure something up and let everybody know what I got.

RidgeRunner · #8 04-16-2012, 07:30 AM

Went with the Kelly Controls KDS 24v 200Amp motor controller. It comes with plugs and pins to make wiring easy.
I attached it to the inside wall of the hatch under the lip for the best weather protection.
trolling motor fix 008.jpg.
I ordered the weatherproofing option for the controller for $15. The programming allows you to set input voltage on the low and high side for protection of the controller. Also delay on, high throttle bypass, throttle input, speed of throttle acknowledgement, percent of battery voltage output and a few other tricks. The controller wouldn't fit where the factory electrics were so extra wires had to be run from the throttle pot, on-off switch and LED light in the head to the control unit under the deck. Electric taped all the insulated signal wires to the power cable for now. Also incorporated my foot switch on the deck so it really is just like it was from the factory. Bottom line was around $200 from soup to nuts. But it works like a charm, fully variable, with a little dead spot at the beginning of the throttle that I was unable to program out. Decided to go with a little heavier controller after talking with Kelly, this one produces no heat that I could tell. Water test is next. I wanna see if the case ever heats up. The beauty is that the controller is one big heat sink, I doubt it will need any additional mass.

RidgeRunner · #9 04-16-2012, 07:43 AM

Remove the old electronics
trolling motor fix 004.jpg
Begin the install of the Controller
trolling motor fix 003.jpg
Yes that is a computer cable hooked to the controller
trolling motor fix 002.jpg
trolling motor fix 001.jpg
And the spot for the LED installation

RidgeRunner · #10 04-16-2012, 07:48 AM

Mounted to the hull under the deck
trolling motor fix 007.jpg
Should stay relatively dry. It is just there on the left in the picture.
trolling motor fix 008.jpg