Plz i am going crazy, help me

Lynxmotion Electronics & Software
1

I am new to the forum but its been quite a while i am looking at the linkmoton products and i have a few questions.

I want to control two motors, so I have a basic atom pro, a mini atom bot board and here i am not sure : should I get the scorpion dual or the dual H-brige to control the motors (the lynxmotion.com/Product.aspx? … egoryID=11)? And why is the scorpion so much more expensive? And one last question: what is the thing about the amps, i realy dont understand, the dual h-brige can only have one per motor, so that gives less current to the motor, so the scropion is better for that. And How do we control the amps??? to get one or two amps, is that with the motor controller that we do that?

thanks for your anwsers

2

just settle down thats wat this site is for :laughing: :wink:

ok, the scorpian motor controller is much more expensive because its a higher end motor controller then the dual H-Bridge, if you look at the specs alone the voltage for the scorpian is rated from 4.8-25 volts, compared to the Dual h-bridge which is 4.8-12 volts

also the peak amps for the scorpian is…i think 6 amps, it also says 12 amps, but the Dual H-bridge is only rated at 2 amps

and finally, the scorpian has an auxillary channel too where the H-Bridge doesn’t

well actually, as long as you hook the Dual H-Bridges up to the same power supply, then is the same exact current

also you cannot control the amperage thats the motors draw, well you can a little bit, but you just vary wat power level its on, the higher the level, lets say full power, the more amps the motors draw, get it? 8)

im not trying to lean you either way, but the scorpian is a higher end motor controller, but the H-Bridge is cheaper and in many of the projects that the motor you want to use the single H-bridge is used to control it

hope this helps, and hope you can understand my ramble :laughing:

3

I would say go for the scorpion. It’s more expensive but 1) it has a much higher range of motors it can drive and 2) it only requires 1 output from the ATOM to dictate speed and direction. The dual h-bridge requires a speed setting i/o pin and a direction i/o pin so to drive two motors it requires 4 i/o pins, and to me i/o is a very precious commodity.

i wouldn’t sweat the amp issue. for motors it boils down to understanding Pulse Width Modulation (PWM), and the scorpion really plays right into that.

4

Look more closely at the product descriptions. The Scorpion is a motor “controller” and the Dual H-Bridge is a motor “driver”. The Scorpion does all the work for maintaining a certain PWM to the motors. The DHB requires the microcontroller do all of the PWM generation. Most Stamp like chips can’t do this AND do other things like monitor sensors etc. With the Atom Pro it is possible to use some hardware to handle this, but the programming is advanced. The Scorpion is probably what you want to use.

5

ok thanks for the replies :slight_smile:

so I will go with the scorpion. so the issue about the amps, it dosent matter, the scorpion will take care of that?
thanks again! :slight_smile:

6

damn I forgot something else: how many volts do we have to plug in the mini atom bot board? do we have to plug some in the scorpion to? if so how many volts and mA?

thanks

7

The issue about the amps should not be a problem for any two motors sold by lynxmotion.
If you’re getting your motors from somewhere else, first verify that they don’t draw more than 3A each at stall.

A dirty exlplanation for your confusion:

Current (a.k.a. amperage) is what your motors will draw from the batteries.
The more strain the motors are under, the more current they will draw.
The more powerful your motors, typically the more current they’ll want.
Remember, it’s the motor that determines how much current flows.
If your electronics can’t handle the current that the motors pull through them, ZAP!
Also, the motor might overdraw your batteries, which will make them lose their rechargability rapidly.

Voltage, on the other hand, puts you in the cockpit.
By raising the voltage, you increase the speed of your motors.
By lowering the voltage, you reduce the speed.
Be careful, though.
Supplying too much voltage can make both your motors and electronics go ZAP!

Smoke is not the best way to start out with a project.

To sum it up:
How much the motor strains determines the amperage.
The voltage you supply determines the speed of your motor.

Keep in mind, the above is just a dirty simplification.
It’ll do, for now, though.

Anything from 6V-9V will be fine to plug into your ABB.
It has an onboard 5V regulator (as do almost every piece of electronics hardware).
I’d suggest using a 9V battery for that.

Into the scorpion, you’ll need to plug the power for your motors.
If they’re 12V motors, you can go with two 6V packs, or two 7.2V packs for a bit more power.
Both are quite safe options.
I’d suggest going with the 1600mAh packs.

What’s this?
My spidey sense is tingling.
I anticipate a question.

What is mAh, you say?
It stands for milliamps per hour.
mAh determines how long the battery will last on a full charge.
A 2800mAh (2.8Ah) pack will last one hour supplying 2.8 amps continuously.
Or, it will last a half hour supplying 5.6 amps continuously.

8

ok thanks,

i looked at the batteries and they look good

the battery paks end in a kind of plastic thing (dont know what it is) anyway its to plug in the ABB (welle I am going to plug a 9V battery in the ABB so it dosen’t matter) or the scorpion controller, but if on the scorpion I want to put two battery packs (6 or 7.2 volts each) i have to cut off one of the plastic things off and solder it to the other pack and plug the second one in the scorpion… how do I do to plug two battery pack to the scorpoon?

:confused:

9

just a suggestion, but i woult do that to the packs, you will need the quick connect to charge the batteries easier, instead just get 2 quick connects and solder those 2 ends together, o yea to get 12 volts from those batteries you have to wire them in series, or you connect one positive…i cant explain it well

heres a url, you want to look at the “connecting in series” part of the artical

zbattery.com/seriesparallel.html

:smiley: hope this helps

10

thanks a lot! :smiley:

where can I get a heat sink for the scorpion? because my motor (GHM-13) takes 3.8 amps so to be safe should I have a heat sink?

11

You won’t need a heatsink the scorpion can handle at least four GHM-13 motors. I am running the same motors you have (actually 4 of them) from my scorpion board. Two on the right channel and two on the left channel. I am using (will be, anyway) Two 7.2V 3500mAh HiMH in series (to make 14.4V) to drive the scorpion and the four GHM-13 motors on my 4WD3 kit. This works fine. I will be upgrading to 14.4 LiON batteries for lighter weight and more power. If you are going to use LiON batteries make sure you have a special LiOn/Li-Poly charger.
By the way… I tested four GHM-13 under full power (spinning with no load in the air) and all four of them were drawing less than 1 amp collectively this includes the scorpion board. The chance of stalling all four motors at once is remote, unless of course you dog or kid is sitting on your robot… :smiley:. If your really worried put a fuse in line on the + battery lead. Say a 2.5 amp fuse (or whatever). If the motors draw more than 2.5amp, the fuse will blow thus protecting your electronics.

Richard

12

man what would I do if this forum didnt exist :laughing: , thanks

so putting a nine volt battery in the ABB is ok???

13

I know this is an old thread, but I’m new here, and it made me laugh… nice post Nick.