dc motor controller diy diagram

[derkiow]

hello forum ...
has any one got any idea where i could get hold of a diy circuit drawing for a controller that wil be used on an electric car handling 100 plus volts and any where up to 400 amps...... all the best...... derkiow

[NC Cams]

Sure: Get A LOT of money and a LOT of MOSFETS and build your own. Simply "scale up" some model train/car speed controls.

in all seriousness, the R/C car boys were EASILY pulling 80 to 100 amps out of nicads in the early/mid 90's - sometimes by design, sometimes by accident. In doing so, they learned how to switch lots of current relatively easily and inexpensively. Car starters readily pull 80 -200 amps as well. There is higher voltage switching going on in the new hybrids but the $'sss are probably NOT DIY affordable.

Swithching THAt much power is not easy nor will it be cheap to do - I'd be disinclined to find that many DIY'ers who'd have balls enough to do it let alone the budget to buy the parts.

If the circuit/switch has to "live", that is one thing, if you only have to throw the switch a couple of times (IE: race car or display concept), a simple "throw away" switch or ganged switches such as an automotive starter solenoid(s) might work as a remote triggerable off/on switch.

IT will be interesting to see the direction this thread morphs into.....

[Karl_T]

Standard stuff for an electric fork lift. Find a bone yard and take the whole unit.

Karl

[derkiow]

I have found mosfets that that can handle 84amps each and 500v for 30$ each, so the price is not too ba, just need a circuit diagram now can anyone help...........derkiow

[derkiow]

thanks for the replies....not any fork lift in the scrap yards where i live in the uk and ones i have found, parts are going for silly money. This project has to be cost effective , i want to save money on my travel cost and be green as well, in that order...derkiow

[Khalid]

I'd be disinclined to find that many DIY'ers who'd have balls enough to do it let alone the budget to buy the parts.

Its difficult to understand...

[WayneHill]

Khalid:

Testicular fortitude

[Khalid]

hahahahahhaa:-)

[derkiow]

balls apart, seriously is anyone out there who can help , can tackle most things but modern electronics are way over my capabilities , just been looking at radio spares site and they do some 200amp/100v mosfet and i been told that i need a pwm device to switch the mosfet i take that would be some kind microchip .........derkiow

[Al_The_Man]

For many years there have been articles,books,groups all engaged in Electric Car development, I would have though that there would be a whole source of information out there for DIY.
Also I remember seeing Application notes from semi manuf like motorola (now Freescale) and others like IR in their HexFet Designers Manual, see if you can get a copy, they have a design for 48v 400a DC motor drive. I got my copy in '93, but it may be available in PDF now, the App note is AN-941b, includes regen as well.
Al.

[NC Cams]

It is one thing to switch on fets to run a DC motor, it is another to switch a potential of nearly 40,000 watts frr an electric car.

We learned some VALUABLE lessons about inductive and resistive switching issues while switching 50-70 amps at 4-6 volts with the R/C stuff and mosfets - switching that much power for an electric vehicle would be something to be done with a lot of care,

Electrons do funny things under those situations and you don't want to be between the path to ground that they may be seeking - especially thru a poorly designed "switching circuit"..

Especially for/by someone who admits that "modern electronics are way over my capabilities", It is hardly a place to learn how to do DIY, OJT switching of a potential of 40,000 watts. If you're not careful, you could get killed or kill somebody.

Did the lights just flicker or was I imagining something???

[derkiow]

thank you for the your replies, i have been doing some looking into dc motors controllers and i have found that mosfets are available right up to 200amps (very expensive) but smaller sizes are cheaper if you by them in quantities of 50 say. Whilst i admit to having only a basic knowledge in electronics i have been connected with high voltage, high current situations all my working life and i treat safety as paramount ... from my investigations so far the electronics are readily available, not expensive when compared to buying a manufactured controller such as curtis etc etc.I have built many projects over the years and you always learn something new and challenging and you overcome a lack of knowledge of something by asking questions, is'nt that what forums are for? .....all the best derk