Difference between motor controllers

I'm fairly new at this so hopefully this hasn't been solved yet.

I'm curious about the difference between different motor controllers. What i'm trying to accomplish is drive 2 15 Amp 24v jazzy motors.

Upon reading several posts, i came across someone recommending the sabertooth 2x25 motor controller http://www.amazon.com/Sabertooth-Dual-25A-Motor-Driver/dp/B008OMQUXC/ref=sr_1_1?ie=UTF8&qid=1401806212&sr=8-1&keywords=sabertooth+2x25 I was a bit sticker shocked on the price though! I read though the specs of the controller and some of the features seem nice such as recharging the batteries when told to slow down

It is also much more expensive then the 24v23 motor controller found on pololu. It has a nice USB interface, but I don't need the usb interface, I simply need to move the motors in forward/reverse from the motor controller http://www.pololu.com/product/1383/pictures

However, I also found this much cheaper motor controller, and could buy two for much less the the ones mentioned above http://www.amazon.com/Controller-Efficiency-Stepless-Variable-Shipping/dp/B00F27NM2E/ref=sr_1_7?ie=UTF8&qid=1401776913&sr=8-7&keywords=motor+controller+15A The question is, can I safely drive this motor controller with the PMW pin on my Arduino Mega? I have read some places that are safety's in place to prevent excessive power reaching the arduino boards, and curious if a motor controller needs to be specifically designed for an arduino board to function safely.

Thanks in advance!

bbark: I'm fairly new at this so hopefully this hasn't been solved yet.

I'm curious about the difference between different motor controllers. What i'm trying to accomplish is drive 2 15 Amp 24v jazzy motors.

Upon reading several posts, i came across someone recommending the sabertooth 2x25 motor controller http://www.amazon.com/Sabertooth-Dual-25A-Motor-Driver/dp/B008OMQUXC/ref=sr_1_1?ie=UTF8&qid=1401806212&sr=8-1&keywords=sabertooth+2x25

that is NOT a controller. it is a driver.

your arduino is the controller.

I'm thinking about using optocouplers to prevent my Arduino board from getting harmed by an excessive voltage. I have not started yet but thinking about it.

I guess you have to provide a seperate voltage to the receiving end of the optocoupler(s) which is a transistor activated by light hitting the base. Now your controller, ok driver, can't damage your board.

You don't even have to use common ground so you can really seperate the circuits.

It's an idea, if you like to use them please study them yourself prior to using them.

I don't think you realize what you are talking about with the cheaper controller. The control input is an analog voltage 0 to 5V. You DON'T have a DAC so you really don't have a way to generate that unless you use PWM with an RC LOW PASS FILTER.

I did't see anything about that controller accepting PWM signals . Can you find a pinout for the board or datasheet that confirms it accepts PWM AND has the two DIRECTION control digital input lines (that I don't see in the photo) ?

It should have TWO DIR and one ENable (PWM) INPUTS.

bbark:
I’m fairly new at this so hopefully this hasn’t been solved yet.

I’m curious about the difference between different motor controllers. What i’m trying to accomplish is drive 2 15 Amp 24v jazzy motors.

What are the specs on those motors (stall current in particular). And also what is the power
source - is it current limited?

What i'm trying to accomplish is drive 2 15 Amp 24v jazzy motors.

Do you need to be able to REVERSE direction or control speed ? (you didn't say what the motors are for)

just how far down the road are you going to push that cart ?

first figure out what you want to do. what you want to move. and then how fast. then look at technologies to move that fast. (or slow) then determine the power needed then knowing power and speed, you can select a motor once you have the motor, you select the driver

now somewhere in that, you need to determine what controller to use. the arduino has it's uses but it is not a universal solution to every application.

what we have so far is to look at motor and used the word controller incorrectly a couple times, then talked about drivers.

if you are moving a 4 ton milling machine, you do not require huge motors. the reason is that they move slow and have high ratios with gearing and threads on lead screws

if you are driving around your 2,000 watt laser at 1,200 ipm, you are not going to use an arduino

my suggestion is to get an UNO or some such, spend the $10 and get a the amazon driver and have at it.

if you are a dumpster diver, get a discarded treadmill. nice motor, nice driver, uses a simple 5k pot to adjust the speed. and you can connect a servo to the pot to isolate things if you so desire.

without knowing speed of your device it is impossible to offer advise. slow is stepper territory, high speed is industrial servo (DC motor with encoder) territory.

what we have so far is to look at motor and used the word controller incorrectly a couple times,

Oooo poor baby! Somebody pee in your corn flakes? 8)

If the jazzy motors are brushed motors, the below h-bridges might be of use.

http://www.ebay.com/sch/sis.html?_nkw=New%20Double%20BTS7960B%2043A%20Motor%20Driver%20High%20power%20module%20smart%20car%20driver%20Arduino&_itemId=251251497215

http://www.ebay.com/itm/Double-BTS7960B-H-bridge-68A-Motor-Driver-Module-For-Smart-Car-Arduino-/170917911112?pt=LH_DefaultDomain_0&hash=item27cb805a48

http://www.ebay.com/itm/DC-15-24V-40A-Brush-Motor-Driver-Module-Drive-Board-80A-Max-For-Arduino-/180980510643?pt=LH_DefaultDomain_0&hash=item2a23476fb3

Wow, thanks for the fast replies!

dave-in-nj: that is NOT a controller. it is a driver.

your arduino is the controller.

Good to know!

mechatron: I'm thinking about using optocouplers to prevent my Arduino board from getting harmed by an excessive voltage. I have not started yet but thinking about it.

This may be useful. I'll do some research and see if that will help. I definitally need to prevent excessive voltage going to the arduino board, since I need to release the electromagnetic breaks that are built into the motor, and have read it can cause a ton of voltage to surge though the system.

raschemmel: I don't think you realize what you are talking about with the cheaper controller.

Very true. I don't believe there were any pins for PWM signals, or any directional controls. Looks like it was bad to assume I could hook up the PWM signal directly to the 0-5v pin. It looks like a very simple board, and does not allow direction to be controlled.

MarkT: What are the specs on those motors (stall current in particular). And also what is the power source - is it current limited?

The source is limited, running off of batteries. I'm not sure of the specs on the motors. I tried finding the specs online but was usuccessful. They were polled off of a Golden GP600. On the side of the motor it says this: Ser. No. p7005250 VOLT: 24 AMP: 14 RPM: 4200 WATT: 260 RATIO: 21:1 BRAKE: Vdc: 24 Yang Jing Industrial Co., LTD

I'm not sure if the stall current is 14 amps or not.

raschemmel: Do you need to be able to REVERSE direction or control speed ? (you didn't say what the motors are for)

Yes I need reverse. This is one of those remote controlled lawn mower projects, and doing it as my arduino project for school.

dave-in-nj: without knowing speed of your device it is impossible to offer advise.

Yep I realized that I should have said what the wheels will be driving. They will be driving a remote controlled lawn mower. I figured the jazzy can push people which should be plenty of power to push a lawn mower though the grass. The speed needed shouldn't be more then 2.5 mph. The lawn mower is an electric homelite 20 inch mower Yes, I'll need some high capacity batteries to mow an entire lawn. The prototype will have 4 9ah 12 volt batteries, wired up so I get 24v with 18AH. I don't expect them to run very long, but I got the batteries for free so I can't complain.

@zoomkat: Perfect links! That is right in the price rang I'm looking at!