go_away

Author Topic: L297 L298 Help Please!!!  (Read 6986 times)

0 Members and 1 Guest are viewing this topic.

Offline reflexsaTopic starter

  • Beginner
  • *
  • Posts: 2
  • Helpful? 0
L297 L298 Help Please!!!
« on: August 28, 2008, 02:08:45 PM »
Hi all,

I am building a small robot that will navigate a maze. The motors I am using are http://www.linengineering.com/line/contents/stepmotors/416-07.aspx
I am using the 416-07-05.
I have the L297 and L298 set up almost like the datasheet, but there is no current sensing and the chopper is not connected. Also I dont really have space for 8 diodes per motor so I dont have those either.
This all seems to work, the L298 gets a bit hot as expected, but the L297 is also getting warm, I find this a bit strange.
Does anyone know if the L297 should be getting warm?

Thanks

Offline airman00

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 3,653
  • Helpful? 21
  • narobo.com
Re: L297 L298 Help Please!!!
« Reply #1 on: August 28, 2008, 02:13:00 PM »
if you are giving it the amount of current and voltage that its rated for then you don't need to worry.
It should prob be warm , does it burn your finger or is it just warm.
Check out the Roboduino, Arduino-compatible board!


Link: http://curiousinventor.com/kits/roboduino

www.Narobo.com

Offline reflexsaTopic starter

  • Beginner
  • *
  • Posts: 2
  • Helpful? 0
Re: L297 L298 Help Please!!!
« Reply #2 on: August 29, 2008, 01:11:57 AM »
The L297 becomes warm to the touch, but the L298 gets a bit hot, I am going too heatsink it today.
As for the motors, the way I see it is that they will draw only the amount of current they were designed to draw because of the resistance of the windings?
The draw a little over 700mA per motor.

Thanks for any help

Offline airman00

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 3,653
  • Helpful? 21
  • narobo.com
Re: L297 L298 Help Please!!!
« Reply #3 on: August 29, 2008, 07:22:06 AM »
OK everything is fine, nothing to worry about
Check out the Roboduino, Arduino-compatible board!


Link: http://curiousinventor.com/kits/roboduino

www.Narobo.com

Offline waymental

  • Jr. Member
  • **
  • Posts: 28
  • Helpful? 0
Re: L297 L298 Help Please!!!
« Reply #4 on: September 09, 2008, 03:04:44 PM »
I am thinking about playing around with the L298. Would it be possible for someone who is using one to post a picture. I just want to get a visual. I have looked it up and read a lot about it already. I would like to see how someone here set it up. Nothing technical just a picture.

Offline Webbot

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 2,132
  • Helpful? 109
Re: L297 L298 Help Please!!!
« Reply #5 on: September 10, 2008, 12:24:38 PM »
There's a schematic etc on my Motor Controller tutorial
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline waymental

  • Jr. Member
  • **
  • Posts: 28
  • Helpful? 0
Re: L297 L298 Help Please!!!
« Reply #6 on: September 10, 2008, 03:38:36 PM »
Yea I checked it out. I was just wondering if someone could post a picture of how they have it used. Nothing technical just a photograph.

Offline ArcMan

  • Supreme Robot
  • *****
  • Posts: 519
  • Helpful? 4
  • Mmmm... Plasma
Re: L297 L298 Help Please!!!
« Reply #7 on: September 10, 2008, 05:08:46 PM »
Here ya go...



Offline ArcMan

  • Supreme Robot
  • *****
  • Posts: 519
  • Helpful? 4
  • Mmmm... Plasma
Re: L297 L298 Help Please!!!
« Reply #8 on: September 10, 2008, 05:43:34 PM »
Oh BTW...
You can add the flyback suppression diodes now or wait until you blow up a couple of L298's first.
Here's the principle...
When you are applying voltage to a motor coil and then you cut off that voltage (which is what a motor drive does), the coil can literally generate thousands of volts.  This is alot of voltage.  You can either supress it to your power rails, which is what the diodes do, or you can use that energy to destroy your L298.  You choose  ;)

Offline Webbot

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 2,132
  • Helpful? 109
Re: L297 L298 Help Please!!!
« Reply #9 on: September 10, 2008, 05:58:38 PM »
The pinouts are a bit of a swine with a 0.1" board - but are long enough that you can bend them to fit without a problem
Webbot Home: http://webbot.org.uk/
WebbotLib online docs: http://webbot.org.uk/WebbotLibDocs
If your in the neighbourhood: http://www.hovinghamspa.co.uk

Offline waymental

  • Jr. Member
  • **
  • Posts: 28
  • Helpful? 0
Re: L297 L298 Help Please!!!
« Reply #10 on: September 11, 2008, 07:19:15 AM »
Nice! Thanks for the picture. This helps me a lot.


Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,658
  • Helpful? 169
    • Society of Robots
Re: L297 L298 Help Please!!!
« Reply #11 on: September 15, 2008, 03:47:30 PM »
Quote
I dont really have space for 8 diodes per motor so I dont have those either.
Look around for Diode Array IC's . . . basically a chip with multiple diodes in it for compact goodness :P

My Axon uses two capacitor arrays, fitting 8 caps in only 2 ICs.

Offline ArcMan

  • Supreme Robot
  • *****
  • Posts: 519
  • Helpful? 4
  • Mmmm... Plasma
Re: L297 L298 Help Please!!!
« Reply #12 on: September 16, 2008, 09:02:14 AM »
Good advice.  Just make sure the diodes are "fast recovery" diodes.

 


Get Your Ad Here

data_list