Hi folks
There is interest in a PWM thread, so here goes.
PWM is Pulse Width Modulation. Basically you can vary speed on a trolling motor by changing the voltage. And most motors do this with several settings, like three forward and two reverse settings. Some motors have a fully variable throttle, like the Minn Kota Maximizer, and this is basically a PWM.
So a PWM increases or decreases the voltage in a clever way: it turns the power on, and turns the power off, modulation. So with the power on say, half the time, and off half the time, you are at half speed. Doesn't seem like this would work, except than you can through the wizardry of electronics do this really really fast, width, so that the motor just thinks it is getting half power all the time. Or 1/10th power width and so on. The key is to modulate through a potentiometer, a twist dial that goes from off, to on, and then almost infinitely variable up to full power.
I am sure there are engineers and techy folks that will say blow holes in all this, but it does work.
So you need this PWM thing and you can but them commercially. but they are pricy. And you can instead have the fun of building your own. Components are about $45 including the unit, connectors and wires. And they change constantly on line, but if you look close, I think they all come from one or two factories in China. Big consideration is make sure that the unit has amp capacity to run a TM, like min 30 amp, 60 better. A lot of these units are designed for small stuff like model airplanes, or something without a motor. Here is what mine looks like, it is a 60 amp unit:
This is a simple one with just on/off variable speed. There are units that also have a rocker switch for forward and reverse and an output LED meter. I went through two of those with issues and settled on a much more robust unit; bigger wires, better heat sink, seems more reliable. Not any difference in cost really.
"Going through" means they failed. Why did they fail? Let me count the ways, noting that these things have really tiny wires and exposed components. One, they really don't like to get wet. Two, the wires are really easy to break, and on some really hard to solder, think aluminum wires. Three, they can get hot which can either open a thermocouple (not too bad), or melt something, bad. Four, touch the wrong things, and they short out = dead.
I found there was too much going on with the rocker switch LED units. Too easy to fail so I went with current unit. I also added a small computer fan to keep it cool. No issues since.
Wire this up #10 silicone wires, so that the output is connected to your TM, and the input to your battery. A fuse is not a bad idea, to match your TM.
Here is another pix of all together:
I may go to more Anderson or Minn Kota connectors to eliminate the alligator clips that do like to play with anchor line and fly line. I leave the TM cable in bottom of boat, takes seconds to connect. See other LiFePo4 thread about battery.
There is a lot going on here and would be happy to answer any questions or assist.
Tight Lines, Ron
There is interest in a PWM thread, so here goes.
PWM is Pulse Width Modulation. Basically you can vary speed on a trolling motor by changing the voltage. And most motors do this with several settings, like three forward and two reverse settings. Some motors have a fully variable throttle, like the Minn Kota Maximizer, and this is basically a PWM.
So a PWM increases or decreases the voltage in a clever way: it turns the power on, and turns the power off, modulation. So with the power on say, half the time, and off half the time, you are at half speed. Doesn't seem like this would work, except than you can through the wizardry of electronics do this really really fast, width, so that the motor just thinks it is getting half power all the time. Or 1/10th power width and so on. The key is to modulate through a potentiometer, a twist dial that goes from off, to on, and then almost infinitely variable up to full power.
I am sure there are engineers and techy folks that will say blow holes in all this, but it does work.
So you need this PWM thing and you can but them commercially. but they are pricy. And you can instead have the fun of building your own. Components are about $45 including the unit, connectors and wires. And they change constantly on line, but if you look close, I think they all come from one or two factories in China. Big consideration is make sure that the unit has amp capacity to run a TM, like min 30 amp, 60 better. A lot of these units are designed for small stuff like model airplanes, or something without a motor. Here is what mine looks like, it is a 60 amp unit:
This is a simple one with just on/off variable speed. There are units that also have a rocker switch for forward and reverse and an output LED meter. I went through two of those with issues and settled on a much more robust unit; bigger wires, better heat sink, seems more reliable. Not any difference in cost really.
"Going through" means they failed. Why did they fail? Let me count the ways, noting that these things have really tiny wires and exposed components. One, they really don't like to get wet. Two, the wires are really easy to break, and on some really hard to solder, think aluminum wires. Three, they can get hot which can either open a thermocouple (not too bad), or melt something, bad. Four, touch the wrong things, and they short out = dead.
I found there was too much going on with the rocker switch LED units. Too easy to fail so I went with current unit. I also added a small computer fan to keep it cool. No issues since.
Wire this up #10 silicone wires, so that the output is connected to your TM, and the input to your battery. A fuse is not a bad idea, to match your TM.
Here is another pix of all together:
I may go to more Anderson or Minn Kota connectors to eliminate the alligator clips that do like to play with anchor line and fly line. I leave the TM cable in bottom of boat, takes seconds to connect. See other LiFePo4 thread about battery.
There is a lot going on here and would be happy to answer any questions or assist.
Tight Lines, Ron
