Shop OBEX P1 Docs P2 Docs Learn Events
R/C 5 channel radio and receiver to control 24v DC motor? — Parallax Forums

R/C 5 channel radio and receiver to control 24v DC motor?

eagletalontimeagletalontim Posts: 1,399
edited 2012-06-15 18:42 in Accessories
I just purchased a 2.4Ghz R/C radio for tinkering around with. I have a few golf cart motors laying around which are 24v DC and rated at 20A. I am hoping to purchase or build a module that plugs directly into the receiver and can control both motors which will be connected to 2 car or lawnmower batteries. The challenge here is to have the ability to have forward, reverse, and speed control. Can someone help point me in the right direction of where I can purchase a plug and play device or locate a schematic to build one?

Comments

  • W9GFOW9GFO Posts: 4,010
    edited 2012-05-01 18:37
    Here's a couple of motor drivers, they each will accept RC signals for control;

    http://search.digikey.com/scripts/dksearch/dksus.dll?site=us&lang=en&mpart=MDL-BDC24&vendor=296

    http://www.dimensionengineering.com/products/sabertooth2x25
  • eagletalontimeagletalontim Posts: 1,399
    edited 2012-05-01 20:16
    Wow! Those have a hefty price on them for sure! Is this something that I would be able to accomplish myself with Mosfets and either the SX28 or Prop? I am really bad at figuring out what mosfets to use or what circuitry to connect to the mosfets to correctly drive anything needing a lot of current. I can blink LED's though :) I do have a few Mosfets laying around that can handle the constant on power, but not pulsing. Would building my own from a motor driver circuit be cheaper and if so, where would I start for building this circuit? Sorry for all the questions! Got to ask to learn.
  • eagletalontimeagletalontim Posts: 1,399
    edited 2012-05-02 19:03
    I take that as a no.... :(
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-05-02 19:10
    I'd take a look at some of the hobby websites. They might have an ESC that would work. I found a couple that could handle the voltage and current but they didn't have go into reverse.

    You could use a DPDT relay to switch the power out to the motors to act as a reverse with one of these ESCs.
  • eagletalontimeagletalontim Posts: 1,399
    edited 2012-05-02 19:13
    I thought of using switches, but I would have no way to control the speed. I would like to eventually change the receiver output to a Prop or SX output which I can control by other device reading like range finders and possibly GPS.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-05-02 19:45
    eagletalontim wrote: »
    I thought of using switches, but I would have no way to control the speed.

    My thought was to use the relay to control direction, not speed. The electronic speed controller would control the speed using the same signal as a servo. The ESCs I could find that could handle the power your want didn't have reverse so the relay was just to change the polarity from the ESC to the motor.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2012-05-03 09:03
    I think you'll find all sorts of information over on the OSMC group here:

    http://tech.groups.yahoo.com/group/osmc/

    There are also some more controller options here:

    http://www.robotpower.com/
  • eagletalontimeagletalontim Posts: 1,399
    edited 2012-05-03 17:46
    I like the motor they have on robotpower! Not too expensive either. Right now, I have been researching on the Prop forum about picking up and using the signal from an R/C receiver. Some good information so far, but I still need to figure out how to power the motors I have. I am thinking of sticking with 12 volts instead of 24 since 2 batteries are pretty heavy. I guess I need to find a Mosfet that can handle at least 12 to 16v and 20 amps.
  • jrjr.jrjr. Posts: 45
    edited 2012-05-19 17:35
    Specifically you reverse any 2 wires (Phases) in the ESC output windings to the motor for the reversal.
    The relay might be a problem on current through the contacts so it might be best to obtain an ESC
    that is capable of the "reverse command", or possibly hack the ESC to reverse the gate drive on the phases.

    The gate reversal method is speculation at this point, but it should work, I can't speak to the EMF feedback
    from the phases, that may need swapping as well.

    I'd love to know the ESC protocols, I've never seen them published anywhere, anybody know a link ?

    I'd figure Parallax has some clue to that, or it would make a good article for interfacing to ESC's

    jack
  • TtailspinTtailspin Posts: 1,326
    edited 2012-05-19 21:57
    Maybe this is something you could use?

    Schematic

    P-channel $1.95

    N-channel $1.95

    This is just for the H-Bridge, You will still have to find the R/C interface you like.


    -Tommy
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-05-20 11:37
    eagletalontim wrote: »
    I have been researching on the Prop forum about picking up and using the signal from an R/C receiver.

    I don't know if you've seen my project that uses the input from a R/C receiver to control four motors using PWM. I'd think some of the objects I used would be useful in your project. I've attached the code to post #63.
  • jrjr.jrjr. Posts: 45
    edited 2012-05-20 17:04
    Duane,

    You're turning out to be more useful than a #1 Phillips

    Thanks again,

    jack
  • RichardFRichardF Posts: 168
    edited 2012-06-15 18:42
    Unless I am mistaken, the output of an RC receiver channel is exactly what you need to drive the HB-25 motor controller (1.0-2.0 msec pulse out). The HB-25 should drive your motors.
Sign In or Register to comment.