How to keep a DC motor driven platform steady

atferrari

Well-Known Member

Most Helpful Member

• Nov 10, 2005

• #1

I have kind of a small round board atop my bot, spinning driven by a DC motor. When the encoder shows that it has turned the exact required amount, I want to keep it steady unable to turn anymore until next order. External forces exist that could make it to rotate in one sense or the other.

Can this (breaking ?) be achieved with a common DC motor or should I resort to a modified RC servo? Whatever helps in saving power, much better.

No previous experience. That's why such a basic question. :?:

 

bloody-orc

New Member

• Nov 10, 2005

• #2

use wormgear. it makes turning very slow, powerful and stiff. or put a brake on the motor (give v+ on poth leads of the motor)

 

atferrari

Well-Known Member

Most Helpful Member

• Nov 10, 2005

• #3

Mechanical solutions to be avoided

I prefer braking by shorting terminals. :idea:

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Nov 11, 2005

• #4

Re: Mechanical solutions to be avoided

atferrari said:

I prefer braking by shorting terminals. :idea:

Click to expand...

That's what 'bloody-orc' said!, but I think the translation made it a little confusing?.

 

atferrari

Well-Known Member

Most Helpful Member

• Nov 11, 2005

• #5

Got it, Nigel!

In fact I was confirming that I understood what he said. :!:

Even I recall there is a chip (sure there are many!) that will do the shorting if the input signals are properly selected. An H bridge, perhaps?

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Nov 11, 2005

• #6

Re: Got it, Nigel!

atferrari said:

In fact I was confirming that I understood what he said. :!:

Even I recall there is a chip (sure there are many!) that will do the shorting if the input signals are properly selected. An H bridge, perhaps?

Click to expand...

Yes, and not just a chip, a discrete H-bridge will do it as well (assuming it's designed to?) - in fact the specific way he worded his response was directly refering to an H-bridge system.

 

theinfamousbob

Member

• Nov 11, 2005

• #7

This might be a bit more than you need:

https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=62033&Row=361165&Site=US

I am going to be using one for a maze robot for competition and am tying it in to an OOPic.

It should do everything you need, and can take a bit of current.

Hope this helps!

 

atferrari

Well-Known Member

Most Helpful Member

• Nov 11, 2005

• #8

Link doesn't work

Hola Bob,
Your link is not working. Could you help?

Gracias.

 

theinfamousbob

Member

• Nov 11, 2005

• #9

Sorry!

The part can be found at:

**broken link removed**

Hope that works!

-Infamous

 

atferrari

Well-Known Member

Most Helpful Member

• Nov 12, 2005

• #10

Got it. Thanks

A good one. Gracias.

 

theinfamousbob

Member

• Nov 15, 2005

• #11

Glad to help.

 

A

addyismad

New Member

• Dec 23, 2005

• #12

use l293dne chip.....
gives kinda regenerative braking for a particular combo of inputs...