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Re: [beam] FullSpeed Dozer

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  • wilf rigter
    Thanks for the layout description Jim. Lots of free drawing programs around if you re interested. Jab you beat me to it. Yours looks fine but from the exercise
    Message 1 of 6 , Jun 1, 2007
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      Thanks for the layout description Jim. Lots of free drawing programs around if you're interested.
      Jab you beat me to it. Yours looks fine but from the exercise of laying out the components around the chip, it seem  there may be a better choice of pin numbers as shown in the uploaded circuit /layout diagram. How well this circuit will  work for you  will depend on the motors which should have a winding resistance of about  30ohms 
       
      wilf
      ----- Original Message -----
      Sent: Thursday, May 31, 2007 10:57 PM
      Subject: [beam] FullSpeed Dozer

      Hi.
      Thanks Jo, Wilf and Jim.
      I gave it a go. don't know if it's right.Please correct me if I'm wrong.
      Thanks for the circuit and the great detail. This is how I see it.
      If this is right I'll build it(thats the part I like and get).)
      I need sleep.
      jab

    • jabmechtech
      ... programs around if you re interested. ... laying out the components around the chip, it seem there may be a better choice of pin numbers as shown in the
      Message 2 of 6 , Jun 1, 2007
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        --- In beam@yahoogroups.com, "wilf rigter" <wrigter@...> wrote:
        >
        > Thanks for the layout description Jim. Lots of free drawing
        programs around if you're interested.
        > Jab you beat me to it. Yours looks fine but from the exercise of
        laying out the components around the chip, it seem there may be a
        better choice of pin numbers as shown in the uploaded circuit /layout
        diagram. How well this circuit will work for you will depend on the
        motors which should have a winding resistance of about 30ohms
        >
        > wilf



        Hi.
        Now I see!
        Thanks I have learned alot from this project.
        I can't build this yet, I'm short on the part count. It seemed to
        keep climbing.:(
        I'm amazed at how manny diferant ways there is to tweek this IC and
        Dozer.
        You guys are awsume!
        Thank you for your time and sharing you ideas.
        I hope others will build these too.
        jabmechtech
        > ----- Original Message -----
        > From: jabmechtech
        > To: beam@yahoogroups.com
        > Sent: Thursday, May 31, 2007 10:57 PM
        > Subject: [beam] FullSpeed Dozer
        >
        >
        > Hi.
        > Thanks Jo, Wilf and Jim.
        > I gave it a go. don't know if it's right.Please correct me if I'm
        wrong.
        > Thanks for the circuit and the great detail. This is how I see it.
        > If this is right I'll build it(thats the part I like and get).)
        > I need sleep.
        > jab
        >
      • Joseph Charles
        Hi Jab, I ve actually come full circle on this. I noticed last night that the 74AC14 full-speed dozer seemed to need a fair difference in light levels on each
        Message 3 of 6 , Jun 2, 2007
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          Hi Jab,

          I've actually come full circle on this.

          I noticed last night that the 74AC14 full-speed dozer seemed to need a
          fair difference in light levels on each of the PD's in order to react.
          If it went into a less well-lit part of the room, it basically became
          a bit 'visually impaired' and just chugged around, not reacting when I
          shaded a PD. I had to make one PD very much darker than the other one
          to get a reaction.

          I assume the largish hysteresis of the 74AC14 inputs, and the very
          high resistance of the PD bridge, when darkish, compared to the 10M
          oscillator resistor, may be at play here. (Could be wrong, though!)

          I swapped out the PD's for a pair of phototransistors, with current
          limiting 1k resistors (one for each PT), and the sensitivity was
          greatly improved.

          But I looked at the increasing parts count and thought, "Hmmm...".

          So I breadboarded the original 'waddle' bot (with reverse), and set it
          loose. I've decided I actually prefer the funny little movement of
          this version, and its sometimes unpredictable reactions, to the more
          'souped-up' versions.

          It think that Wilf's 74AC240 BullDozer circuit won't have the same
          insensitivity problems that my 74AC14 version had, so it might be fun
          to have a go at building that one.

          This also confirms why I like to use breadboards (and some sort of
          test base, too). You can chop and change a circuit, and try as many
          variations as you like, before settling on a final design.

          Jo


          --- In beam@yahoogroups.com, "jabmechtech" <jabmechtech@...> wrote:

          > I can't build this yet, I'm short on the part count. It seemed to
          > keep climbing.:(
        • jing.alcantara
          hi Jo, i just finished my mobile platform and hooked up my DOZER and guess what? it just sits there DOZING. i know it works cuz when i lift the base the motor
          Message 4 of 6 , Jun 2, 2007
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            hi Jo,

            i just finished my mobile platform and hooked up my DOZER and guess
            what? it just sits there DOZING. i know it works cuz when i lift the
            base the motor runs so i guess i needed a motor driver. but i dont
            have the 74***245 chip, what i got is the 74ACT240. i tried googling
            for a circuit that uses this chip but my efforts turn futile. can you
            give me a schematic for a motor driver that uses the 74ACT240 chip.
            thanks again.

            jing

            --- In beam@yahoogroups.com, "Joseph Charles" <jodicalhon@...> wrote:
            >
            > Hi Jab,
            >
            > I've actually come full circle on this.
            >
            > I noticed last night that the 74AC14 full-speed dozer seemed to
            need a
            > fair difference in light levels on each of the PD's in order to
            react.
            > If it went into a less well-lit part of the room, it basically
            became
            > a bit 'visually impaired' and just chugged around, not reacting
            when I
            > shaded a PD. I had to make one PD very much darker than the other
            one
            > to get a reaction.
            >
            > I assume the largish hysteresis of the 74AC14 inputs, and the very
            > high resistance of the PD bridge, when darkish, compared to the 10M
            > oscillator resistor, may be at play here. (Could be wrong, though!)
            >
            > I swapped out the PD's for a pair of phototransistors, with current
            > limiting 1k resistors (one for each PT), and the sensitivity was
            > greatly improved.
            >
            > But I looked at the increasing parts count and thought, "Hmmm...".
            >
            > So I breadboarded the original 'waddle' bot (with reverse), and set
            it
            > loose. I've decided I actually prefer the funny little movement of
            > this version, and its sometimes unpredictable reactions, to the more
            > 'souped-up' versions.
            >
            > It think that Wilf's 74AC240 BullDozer circuit won't have the same
            > insensitivity problems that my 74AC14 version had, so it might be
            fun
            > to have a go at building that one.
            >
            > This also confirms why I like to use breadboards (and some sort of
            > test base, too). You can chop and change a circuit, and try as many
            > variations as you like, before settling on a final design.
            >
            > Jo
            >
            >
            > --- In beam@yahoogroups.com, "jabmechtech" <jabmechtech@> wrote:
            >
            > > I can't build this yet, I'm short on the part count. It seemed to
            > > keep climbing.:(
            >
          • jabmechtech
            ... need a ... react. ... became ... when I ... one ... it ... fun ... I ll try swapping out the IR LEDs for PRs insted with the 1K resistorlike you did. But
            Message 5 of 6 , Jun 2, 2007
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              --- In beam@yahoogroups.com, "Joseph Charles" <jodicalhon@...> wrote:
              >
              > Hi Jab,
              >
              > I've actually come full circle on this.
              >
              > I noticed last night that the 74AC14 full-speed dozer seemed to
              need a
              > fair difference in light levels on each of the PD's in order to
              react.
              > If it went into a less well-lit part of the room, it basically
              became
              > a bit 'visually impaired' and just chugged around, not reacting
              when I
              > shaded a PD. I had to make one PD very much darker than the other
              one
              > to get a reaction.
              >
              > I assume the largish hysteresis of the 74AC14 inputs, and the very
              > high resistance of the PD bridge, when darkish, compared to the 10M
              > oscillator resistor, may be at play here. (Could be wrong, though!)
              >
              > I swapped out the PD's for a pair of phototransistors, with current
              > limiting 1k resistors (one for each PT), and the sensitivity was
              > greatly improved.
              >
              > But I looked at the increasing parts count and thought, "Hmmm...".
              >
              > So I breadboarded the original 'waddle' bot (with reverse), and set
              it
              > loose. I've decided I actually prefer the funny little movement of
              > this version, and its sometimes unpredictable reactions, to the more
              > 'souped-up' versions.
              >
              > It think that Wilf's 74AC240 BullDozer circuit won't have the same
              > insensitivity problems that my 74AC14 version had, so it might be
              fun
              > to have a go at building that one.
              >
              > This also confirms why I like to use breadboards (and some sort of
              > test base, too). You can chop and change a circuit, and try as many
              > variations as you like, before settling on a final design.
              >
              > Jo
              >
              > Hi Jo.
              I'll try swapping out the IR LEDs for PRs insted with the 1K
              resistorlike you did. But use the Motor drive circuit.I'll also have
              a go at the 2nd circuit with the 330ohm resistor and diode and single
              74hc14.
              Mine just spun in one direction unless I plased my hand almost on it
              to shade the eyes then it falowed my hand(like it was hungry for
              fingers) :).
              When I can get some more parts I'll build Wilfs BullDozer.
              Thank you. I have learned so much from this project and had a blast
              doing it. I'm sorry I still don't understand the bread board thing, I
              can't get stuff to work until I build(and Rebuild)it.
              Thanks.
              Jab
              > --- In beam@yahoogroups.com, "jabmechtech" <jabmechtech@> wrote:
              >
              > > I can't build this yet, I'm short on the part count. It seemed to
              > > keep climbing.:(
              >
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