luvxu wrote:Hi Monstarr,
Thank you for the explanation, it really help. Would you mind share the part numbers for your motor, pwm and battery. Some pictures or diagrams would be helpful. If the system has been working reliable for you then I just want to copy it so that I don't have to deal with any unpleasant surprise of building it from scratch.
I use a 24 V 80'-ish' lb Motorguide trolling motor with a Kelly 24 V brushed controller.
http://kellycontroller.com/kds36100e100 ... p-270.html
Any PWM brushed controller built for the operating voltage range will do. Just check the nominal current handling. There is nothing wrong with a little additional current handling because when trolling you will ask max current all the time because of the waterdrag. But this is common sense.
Set up is easy. Just hook on the battery to the input (& the key ignition). Connect the throttle input wires (5v supply, 0-5 v & GND) to the gas handle or a regular pot meter. Then installed the black & red (direct lead) motor wires to the controller output.
I mounted the Kelly controller on an aluminium plate and then bolted the plate to the original mounting holes of the speedswitch within the housing. Furthermore I installed a small fan and air-in- & outlets to get the airflow needed for cooling.
For easy throttle control I clamped a flexible vertical joint around halfway to the shaft and insert a arm-extension on this joint. On the end of this extension I mounted the gashandle. This way I get a similar way of control as a standard ICE outboard would have.
As battery I use a 8S (24V) LiFePO4 70 Ah battery. But this could also be a regular series lead setup.
Adding PWM control this way can be done very cheaply. You only see this type of speedcontrol with more expensive type trolling motors. Although the overall design could have been better, especially the flexibele connection on the motorshaft is not very rigid and has room for improvement, but I have used it a few times and I am happy with the result.
Only thing I don't have anymore is reverse motion. The Kelly controller doesnt have this function. You can use a switch to flip the motor leads but normally those are not build for higher amps or are very costly. I didnt look into this a lot because I dont miss it that much. Perhaps someone here has a good solution for this problem ?