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Motor Control

This page includes a view of my (limited)knowledge of motor control and a page on my speed controller design.

Speed Controller Design

Since I've decided to build my own speed controllers first, I had to learn the basic electronic design of an H-Bridge. This proved to be the fun part(NOT!). I spent 2-3 days of hard research trying to figure out how an H-bridge works and how to go about building one to handle the motors I have. By the 4th day my head hurt and I could draw an H-bridge diagram from memory and completely explain low-side drivers and the high-side drivers.

First I had to determine how much stall current the motors pulled when stalled. In order to do this I ether had to hook an ammeter in series with the motors or a multimeter that was setup to handle amps via a dial or external components(which you can find information on anywhere on the net). After I determined the stall current I needed to choose some MOSFETs(basically solid state switches) that could handle the current and voltage I was gonna put threw them. I choose the IRFZ46 MOSFET for my setup as it was cheap and it could handle the required input. A nice thing about MOSFETs is that you can parallel them together in a circuit to make the circuit handle more current. I decided that 3 per leg of the H-bridge should be enough.

Next step I needed to take was to test my knowledge that I had learned. I took 4 of my MOSFETs and a prefboard and wired them up in a VERY simple H-bridge. After I got this working with a small motor and my BS2 I knew I could build a larger one without too much hassle.

Here is a link to my planned design setup for the speed controllers. I will also post the pictures of the designs when I get a chance to..

Now I'll give you some links to sites that contain information about speed controllers and how they work.

A good project for a cheap speed controler
GREAT information on how they work
The name says it all
Slides on building a speed controller
Excellent information from a speed controller manufacture
UK Robot Wars builder's homebuilt controller info
another UK Robot Wars builder, good information

And if you don't want to build one here are some companies that provide them

Makers of the 24v Victor 883
Good yet cheaply priced speed controllers, wide selection of choices
The Bently of Speed Controlers(price wise)
Decent priced medium duty speed controllers
Building Speedcontrollers for Cheap