MOSFETs

[Max]

Hi,
I am trying to build my own heavyweight speed controllers so obviously need some high current MOSFETs to make a pair of MOSFET banks. I am going to be running at 18v. So if anyone's got some high power FETs which they want to part with please let me know. I am not sure on current rating as I will just change the number of FETs I use depending on their rating, but I'd like each bank to be able to handle 250A.
Thanks,
Max

[Bacon Wizard]

I'm not at home just now: in Widnes, but i have some. Will look and find out what they run and post back here mid-week.

[typhoon_driver]

Buy from rs or farnell. You will get what you need exactly

[Max]

Do tou think 3 of these:
http://uk.rs-online.com/mobile/p/mos...stors/7481762/
Would be enough to run a Bosch 400 on 18v. They are rated at 175A each at 55v so should give 525A continuous which sounds like plenty but I'm not sure if you can trust that current rating. I'm also not sure how you would connect motor wire to the MOSFET so it can handle that sort of current, anyone got any advice?

[typhoon_driver]

Go buy a speed controller. The questions you just asked highlight the fact that you are nowhere near making your own speed controller

[blazerbotics]

Don't bother trying to make your own speedos, many have tried, most have failed. Would say try and get a set of 4QD NCC70s, but not sure how you would go with 18v as their either 12 or 24 volts.

[Max]

I thought you'd say that, the problem, as you point out Alan, is that there are very few controller that run on 18v, I don't want to overvolt my motors up to 24v as this will then fry the esc. I am also trying to build the robot to learn, I want to learn about electronics and am slowly getting there.

[typhoon_driver]

Run the motors on their rated voltage