My neighbor owns a scrap metal yard which he lets me pick over as needed. I have an assortment of DC motors from 4 250W 24V motors to a 2.5HP 90VDC from a treadmill. I am looking at building a go kart for myself and my kids to play with but need some help with the PWM controller.
It would be great if I could find a single design that would work for all standard DC motors (not brushless of course) and just vary the input voltage from 12-90V. My understanding is that I can run a 0.25HP motor on a 5HP controller, but not the other way around. Assuming the cost isn't significant to trade out some MOFSETs it would be great to have a single design to replicate as needed.
I have seen several sets of plans such as http://www.instructables.com/id/How-to-Make-an-Universal-DC-Motor-Speed-Controller/ that use a 555 timer, one that uses a 556 timer and so on. Now my thinking that that there are many components in the plans that would stay the same such as the potentiometer and timer since those won't have tons of amps flowing through them, but if I get larger MOFSETs, do I need to get larger capacitors and resistors?
I am not an EE, but I would imagine there will be a couple things to consider when trading an IRFZ46 (https://www.digikey.com/product-detail/en/infineon-technologies/IRFZ46NPBF/IRFZ46NPBF-ND/811998) for a beefier MOFSET such as:
Now I am hoping to not be building a 100HP controller like this guy: http://www.instructables.com/id/Homemade-100-HP-Motor-Controller-for-an-Electric-C/ since it cost him a few hundred, but I figured that with the plentiful nature of DC motors in my life, buying them retail would really add up.
The first link for the universal controller looks pretty simple, what do I need to do to be able to power a large HP motor with it?
In other news, my neighbor just bought a bunch of electric trains from the city which are getting scrapped which have about 250 300 amp hour lithium batteries weighing 156lbs each. I thought I might just throw that in behind the seat of the go kart. I figure if it puts out enough amps, I could convert the voltage from 12V to anything needed for the controller without needing to wire them in series.