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60+ Amp Speed Controller — Parallax Forums

60+ Amp Speed Controller

crgwbrcrgwbr Posts: 614
edited 2007-01-21 16:23 in Robotics
Hey Everyone,

I just finished the speed controller for my heavy-weight (200 lbs)·Stamp controlled Telepresence bot.· Thought you might like to have the pcb, to build one of your own or something.··I etched it onto a 4" X 10" 8oz copper·board, it can handle 60 A continuous, per channel.· Depending on the board you choose, it should be able to handle the following amounts of current per channel...

1oz = 12·A
2oz = 22 A
3oz = 28 A
4oz = 36 A
5oz = 42 A
6oz = 48 A
7oz = 54 A
8oz = 60 A
9oz = 64 A
10oz = 70 A

PWM is provided be two 555 timers controlled by two digital pots.· Then everything is routed through a PCF8547 I/O Expander, this means that the whole thing can be be controlled by a two wire I2C interface, and that 8 of these can be of the same bus.· Oh, and I forgot to mention, the whole thing is isolated by six 4N25 optocouplers.· To open the file you'll need Express PCB (Click here to Download).· Please post any revisions you make to it or errors you find in it.· Also, here's a link to help explain using I2C with the BS2.

Thanks to Everyone who helped me with this,
crgwbr

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NerdMaster
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pcb
pcb
60 Amp Duel H-Bridge.pcb
50K

Comments

  • HavoKaneHavoKane Posts: 109
    edited 2006-09-09 13:00
    awsome man. couple questions though, can this control two motors independently? how much did it cost you to build? where did you order the parts? will this only work thru I2C, or can it be used with the servo ports as well?

    thanks

    Post Edited (HavoKane) : 9/9/2006 1:32:14 PM GMT
  • HavoKaneHavoKane Posts: 109
    edited 2006-09-09 13:56
    also, when i open the .pcb file in ExpressPCB, i get an error saying that the file could not be linked back to the schematic (.sch). could you post a copy of your schematic? im very interested in building one of these for myself
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-09-10 20:58
    You may have to download Eagle V4.16 from www.cadsoft.de to read it.

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • crgwbrcrgwbr Posts: 614
    edited 2006-09-11 13:41
    It should cost around $40-50 to build, I ordered most of my parts from Jameco.· Yes, it can control two motors independantly, each from 0% to 99% duty cycle.· I would post a schmatic, but I don't have one (the one it's linked to is just of the H-Bridge circuitry), I designed it right in Express PCB.· As far as the error message goes, just hit ok, or you can download it again from this post, it's not linked to anything.· One more thing, It can only be used with I2C, not servo ports.· No problem though, I2C only takes 2 I/O pins and a little knowledge of the·SHIFTOUT command.


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    Post Edited (crgwbr) : 9/11/2006 11:51:49 PM GMT
    pcb
    pcb
    60 Amp Duel H-Bridge.pcb
    50K
  • HavoKaneHavoKane Posts: 109
    edited 2006-09-13 02:51
    i cant open it at all with eagle. and all i get is the board layout in express pcb. it says it needs a .sch file to do anything else.
  • crgwbrcrgwbr Posts: 614
    edited 2006-09-13 12:11
    I tried it on another computer, make sure you save it, not just open; also, make sure you use the last one I posted, not the first one.

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    NerdMaster
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  • prime3prime3 Posts: 2
    edited 2006-12-09 21:15
    Sounds good!! Does it do direction control too?· Will it work at 12v dc?· How do i pull up a list of components in express pcb?· So this controller would be isolated from the stamp via the optos.· Thats good.·· Would it need a heat sink or fan to control 3 45-50 amp motors at 12vdc?· I would need three of them right, but only use 2 stamp IO pins.· I want to hook a serial keyboard to a stamp 2, then then control the board.· I'd use the arrow direction keys on the keyboard to send serial ascii to the stamp and it would send the appropriate signal down the I2C.· I would be making rapid adjustments in speed and direction on the keyboard.· Does this sound like a good fit?
  • crgwbrcrgwbr Posts: 614
    edited 2006-12-09 21:34
    prime3,

    This controller is a duel H-Bridge driver, therefore it does do direction control.· No, you would only need two of these, as each one can control two motors.· Yes you will need both heatsinks and a fan to cool, even at 0.016 ohms, 50 Amp will genetate a lot of heat (so be careful).· One final thing, as you seem to be a bit of a beguiner, I would recomend just buying somthing like the HB-25.· The programing required to make this thing work is a bit complex (unless your using a BS2-P).

    Hope you get your project working,

    crgwbr

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  • prime3prime3 Posts: 2
    edited 2006-12-09 22:14
    Dual channel at 70 amps?? WOW· How many mosfets would you need to run that kind of current with no fans or heat sinks?··Probably a hundred :-)

    What is the range of supply voltage for the motors?

    How can I find the parts list?


    The Parallax controller you speak of is simpler, but at $50 per I would have to buy two per motor to handle the amps if thats possible,·and I would still be stretching it a bit because at stall the motors will draw more. Have you seen anyone using a bs2 use the "open source motor controller" ?· Its rated at hundreds of amps but don't know if its compatible.

    I'm not exactly a newbie, I'm just rusty, about 5 years since I worked with the stamp2.· I haven't worked with I2C yet though.

    If the BS2P is easier, I'd buy one·to make it work.

    Did you make your own PCB?
  • bennettdanbennettdan Posts: 614
    edited 2006-12-10 05:52
    crgwbr

    Nice speed controller what type of heat sink are you using...?
  • Paul Sr.Paul Sr. Posts: 435
    edited 2006-12-10 13:05
    Would it be possible for you to post the .sch file?

    Thanks!
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-12-10 13:32
    crgwbr said...
    Please post any revisions you make to it or errors you find in it.
    Now, crgwbr, have you actually made this?· That is,·have you a working model?
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-12-15 10:51
    Let's see, 60 watts is twice the power of my soldering iron and would make a deafening stereo amp.
    What would that be in HP?

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-12-15 15:56
    PJ gave me the conversion rate and apparently 60watts = 0.08 horsepower or about 1/12th of an HP.

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • WarrlokWarrlok Posts: 77
    edited 2006-12-27 07:06
    Kramer said...
    PJ gave me the conversion rate and apparently 60watts = 0.08 horsepower or about 1/12th of an HP.

    ····· I think its volts * amps.
    ··········
    ·············· (·60 amps * 9.6 volts = 576 WATTS )

    ············· u could do a segway· scool.gif

    ·········· i got· the new sabretooth from lynxmotion its got regenerative braking
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-12-27 10:59
    Ooops...
    That's about 5 HP. I suspect that is nearer to my Yamaha 100cc scooter.

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • stamptrolstamptrol Posts: 1,731
    edited 2006-12-27 19:19
    Gents,

    At 746 watts per HP, its 576/746= 0.768 HP.

    PJ's conversion is right as well. ( 60w = 0.08 HP)

    Cheers

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    Tom Sisk

    http://www.siskconsult.com
    ·
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-12-28 15:54
    Obviously, some of us haven't been thinking things through.
    Intially I was trying to compare the wattage to something tangible, but I mess up the math.
    576 watts could easily provide heat for a small corner of room.

    What size wire do you need for 70 amps?
    Seems to 70 amps would be about the same size wire as mains for a small cottage or older home.
    The output stage must be quite robust.

    This is the whole problem with the low voltage/high amperage path for high power devices. The hardware becomes awkward.
    Even airplanes use voltages in the 40 volts range [noparse][[/noparse]trying to stay low to minimize sparks causing fuel leak ignition].

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • WarrlokWarrlok Posts: 77
    edited 2007-01-21 16:23
    stamptrol said...
    Gents,

    At 746 watts per HP, its 576/746= 0.768 HP.

    PJ's conversion is right as well. ( 60w = 0.08 HP)

    Cheers

    ···· the HB-25 is 25amps and is good to a 1/2hp .ie 50 amps per hp . have i got this confused some how , never been good with math . if anybodys doing this it would·be nice to know how it turns out thanks and····················· "great job man"

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    Problems are the "roads" of life,
    solutions are only "onramps" to the next problem



    ············································· "Brad Smith"


    Post Edited (Warrlok) : 1/21/2007 4:46:03 PM GMT
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