Need a high amp H-bridge and if possible a PWM to go along.... :)

[Nicksan]

I Started this project..... to modify an electric wheelchair for radio control but the controller I bought will not work and now I am stuck with 2-24 volt motors and 2 12v batteries at somewhere around 30Ah each. The controller will not handle the amps that the motors pull, so I am looking for a high amp H-bridge, either pre-made or just the schematic. Of course if I could get some speed control with it that would be great.
surprisingly I have not found any schematics online that handle large amps, that I could make
Anyone have any ideas or links?
Thanks.

 

[Nigel Goodwin]

I Started this project..... to modify an electric wheelchair for radio control but the controller I bought will not work and now I am stuck with 2-24 volt motors and 2 12v batteries at somewhere around 30Ah each. The controller will not handle the amps that the motors pull, so I am looking for a high amp H-bridge, either pre-made or just the schematic. Of course if I could get some speed control with it that would be great.
surprisingly I have not found any schematics online that handle large amps, that I could make

That's because it's an EXTREMELY complicated project to build, and while you suggest 30A, the starting and stall currents are more likely to be 300A.

You might try checking the 4QD site?.

 

[Nicksan]

I originally was going to use the variable pot that came with the wheelchair and control it with a couple servos rigged up with modified horns, using a RC radio, it would have worked fine but Instead I got the idea that, that was too easy, now I wish I had kept it simple.
I may have to save up the money and go with a bigger vantec.

 

[Nicksan]

I found some controllers and a RC interface that are pretty cheap. The controllers can handle 35Amps continuous but there are no specs for max amps. I have read that these controllers have been used on wheelchair motors and work fine. What do you think?
Heres a link.
**broken link removed**

 

[mneary]

The MC7 has some features you may or may not like.

Reversing is done with relays. This isn't a problem unless you want smooth bidirectional control (probably only important when balancing).

The IRFZ48 are 50A devices, three in parallel is only 150A and this doesn't account for the board and the relays.

They don't mention a current limit. You should ask them.

 

[Nicksan]

Using relays in reverse is not that big a deal, but with the RC adapter it should be smooth, if not I dont mind. I am going to give em a call next week some time.
The author of the book, build your own all terrain robot- uses these controllers with wheelchair motors and claims they work fine, although mine are not the exact some motors, they should be pretty close to the same specs.
I decided to put this project on hold because I have the parts on hand for something different and started it a couple days ago. but I want to get working on it as soon as I can.