ESC circuit for controlling a large robot

[Dblade]

editWell, I building a semi large robot currently and have run into a large snag. While I'm more of mechanical guy (mill lathe weld) and have built many a kit circuit , But I've never really designed my own circuit or printed my own PCB.

Here is the robot, Its about 39" long and 27" wide, the tires are 12" and linked via some #40 chain and sprockets. The motors that you see in the pic didn't work out (the gear boxes worm gears were stripped so they slipped alot)
The can of pepsi is for comparison
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I'm planning on using two ESC circuit driven from a SSC-32 serial to servo control (so I can have room for a pantilt for the camera and maybe a 6 joint arm later), and having the SSC-32 controlled from a little ASUS Eee netbook or from a hacked router (I've been leaning towards router)

So I'm starting from this circuit.
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A Pic12F675 based ESC, I'm using either two 350watt electric scooter motors or two new power wheel chair motors(it depends on which auction I win)

So I can safely say I'll have a high amp draw a full load probably around 20-40amps to much for a single mofset.

I asked around an a found some samples from onsemi a dual High Low N channel mosfet driver NCP5106, and 10 NTP5411NG 60v 75amp N-channel mosfets.

https://www.onsemi.com/pub/Collateral/NTB5411N-D.PDF

https://www.onsemi.com/pub/Collateral/NCP5106-D.PDF

So in my first time using eagle I made this, in the diagram you can see IRF540s (eagle didnt have NTP5411's and NCP5106s)

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Now is the pickle, I have to put in a order to mouser in the next couple days(friday) for the pics and the other 26 mofets along with some parts for work

What should I add to the circuit to make it work?

 

[IanP]

I've made some suggestions with regard to bypass caps and separation between the battery voltage and "control" voltages ..
All unmarked caps can be 0.1µF ..
As Q17 you can use any small signal NPN (2N3055 is a big fellow) such as 2N2222, BC547, 2N3904 etc.
And R2 - I'm not sure what is the reason of wiring it to connector - it looks like a pull-up and as a such should be connected to +5V ..

Rgds,
IanP

 

[Dblade]

Thanks for your suggestions!

I'll cook up a new (better) schematic with the caps in it.