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Re: [beam] Maxibug v3 input needed

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  • wrigter
    What will be the short circuit current of the 9V solar panel? I less than 100mA, a simple 5V 1W zener can be used to limit the voltage across the cap. On the
    Message 1 of 12 , Sep 13, 2010
      What will be the short circuit current of the 9V solar
      panel?
      I less than 100mA, a simple 5V 1W zener can be used to limit
      the voltage across the cap.

      On the other hand, a number of toys use a 5.5V supercap for
      energy storage and charge in about 10 seconds from a 9V
      battery charging station (possibly through a small series
      resistor). The super cap becomes very leaky above 6V and to
      that extent limits the voltage rise. Not sure how it affects
      the life of the cap but it cerainly sucks the life out of
      the battery.

      You'll have to check the archives to see who originated the
      maxibug circuit, I merely expanded on it in V5, which uses a
      solar charged battery station to charge the maxibug V5 in 10
      seconds. When charged the bug is photophobic and reverses
      away from the LED to exit the charger. It then looks for
      shadows until the cap charge drops below a lower threshold
      and the bug becomes photophylic. The charger LED then
      becomes an irresistible attraction for the bug and after
      mating of the charging contacts, the cap is quickly
      recharged.

      There was some discussion at the time of using upper and
      lower rings around the maxibug body as charging contacts so
      that when two bugs collided, the one with the lower charge
      could steal some energy from energy rich bug. That could
      also be used to revive stranded bugs.

      Wilf

      ----- Original Message -----
      From: "Jack" <grsshpr875@...>
      To: beam@yahoogroups.com
      Subject: [beam] Maxibug v3 input needed
      Date: Mon, 13 Sep 2010 16:11:00 -0000

      >I'm thinking of using a Maxibug
      ><http://costaricabeam.solarbotics.net/Circuits/Vores/Maxibu
      >g%203%20(Sola\ rised).png> v3 popper to give mobility to
      >an outdoor daytime pummer. The conditions will be less than
      >ideal considering the intermittent shade from overhead
      >trees covering about 50% of the bots operating area. My
      >idea is to charge a 5.5V 1F gold cap with a 9V solar panel
      >instead of the prescribed 5V setup to overcome shady
      >weather, angle of the panel to the sun, etc. To prevent
      >overcharging the cap under continuous sunlight I thought I
      >might use an 8212 with a FET between the panel and cap to
      >connect and disconnect the panel from the circuit at 5V.
      >This same setup would be applied to the Miller SE pummer
      >that needs ~4V. Does this sound reasonable? Another concern
      >is the capacitors volatge rating. Are caps rated for the
      >voltage they hold or the voltage they're exposed to? I'm
      >not sure... Anyhow, I thought I'd run my plan by the pros
      >here before I start going on a component buying spree lol
      >
      >I'm also curious if anyone knows of any videos of the
      >mazi/maxibug in action. I haven't found any myself.
      >
      >
    • Jack
      ... The current is just shy of 100mA so that would work. So connect the zener across the leads of the cap? It sounds so easy. ... These gold caps are pretty
      Message 2 of 12 , Sep 14, 2010
        --- In beam@yahoogroups.com, wrigter <wrigter@...> wrote:
        >
        > What will be the short circuit current of the 9V solar
        > panel?
        > I less than 100mA, a simple 5V 1W zener can be used to limit
        > the voltage across the cap.

        The current is just shy of 100mA so that would work. So connect the zener across the leads of the cap? It sounds so easy.

        > On the other hand, a number of toys use a 5.5V supercap for
        > energy storage and charge in about 10 seconds from a 9V
        > battery charging station (possibly through a small series
        > resistor). The super cap becomes very leaky above 6V and to
        > that extent limits the voltage rise. Not sure how it affects
        > the life of the cap but it cerainly sucks the life out of
        > the battery.

        These gold caps are pretty pricey for a BEAM project IMO. I'm not sure I want to give them a hard time and possibly shorten their lifespan. I'll go with your above stated suggestion.

        > You'll have to check the archives to see who originated the
        > maxibug circuit, I merely expanded on it in V5, which uses a
        > solar charged battery station to charge the maxibug V5 in 10
        > seconds. When charged the bug is photophobic and reverses
        > away from the LED to exit the charger. It then looks for
        > shadows until the cap charge drops below a lower threshold
        > and the bug becomes photophylic. The charger LED then
        > becomes an irresistible attraction for the bug and after
        > mating of the charging contacts, the cap is quickly
        > recharged.
        >
        > There was some discussion at the time of using upper and
        > lower rings around the maxibug body as charging contacts so
        > that when two bugs collided, the one with the lower charge
        > could steal some energy from energy rich bug. That could
        > also be used to revive stranded bugs.
        >
        > Wilf

        I gave your v5 a look but it looks to have a lot of custom fabrication involved. I've still got all my fabrication efforts focused on my QLF totem pole thing (almost a year in the works). Nice adaptation of the mazibug btw.

        Thanks for the advice, Wilf!
      • Jack
        An update and a possible problem... The update: Got the bug to work on the breadboard and motor around with the power of the sun. I found I ll need ~300mA to
        Message 3 of 12 , Sep 21, 2010
          An update and a possible problem...

          The update: Got the bug to work on the breadboard and motor around with the power of the sun. I found I'll need ~300mA to make it overcome shady conditions and using an 8V panel should be enough.

          I haven't done the zener voltage regulation yet (still haven't gotten the fat 1W resistor for it).

          The platform I've made uses Solarbotics GM17s and it moves predictably slow. When the CdS cells are at almost equal resistance both motors experience whiny-power-sucking-228:1 jitter and the bot almost comes to a halt. I'm going to try the GM17 gear set from Didel that has 51:1 and 100:1 ratios I believe. Hopefully that helps some.

          I used a SPST toggle to simulate the tactile sensor. When I threw the switch and reset it the bot would continue in reverse almost 1.5 times in a circle before resuming forward. I replaced the 10uF cap with a 1uF cap and now it reverses about 45 deg and goes back to normal.

          Now... the problem: While the bot it mobile it doesn't ever go photophillic. I figure it has something to do with the LED (not the FLED) not lighting up? The voltage will easily exceed 5V. I don't know what to do. Any help appreciated!
        • Jack
          ... I meant photophobic. It only orients towards the light. Never heads away.
          Message 4 of 12 , Sep 21, 2010
            --- In beam@yahoogroups.com, "Jack" <grsshpr875@...> wrote:
            >
            >... While the bot is mobile it doesn't ever go photophillic...>

            I meant photophobic. It only orients towards the light. Never heads away.
          • wrigter
            To slow the switching between the two motors when the LDRs are equally illuminated, insert a 1M resistor between the LDR midpoint and 240 pins 15/17. The LED
            Message 5 of 12 , Sep 21, 2010
              To slow the switching between the two motors when the LDRs
              are equally illuminated, insert a 1M resistor between the
              LDR midpoint and 240 pins 15/17.

              The LED should be on while charging. Can you confirm this?

              wilf

              ----- Original Message -----
              From: "Jack" <grsshpr875@...>
              To: beam@yahoogroups.com
              Subject: [beam] Re: Maxibug v3 input needed
              Date: Tue, 21 Sep 2010 22:04:21 -0000

              >An update and a possible problem...
              >
              >The update: Got the bug to work on the breadboard and motor
              >around with the power of the sun. I found I'll need ~300mA
              >to make it overcome shady conditions and using an 8V panel
              >should be enough.
              >
              >I haven't done the zener voltage regulation yet (still
              >haven't gotten the fat 1W resistor for it).
              >
              >The platform I've made uses Solarbotics GM17s and it moves
              >predictably slow. When the CdS cells are at almost equal
              >resistance both motors experience whiny-power-sucking-228:1
              >jitter and the bot almost comes to a halt. I'm going to try
              >the GM17 gear set from Didel that has 51:1 and 100:1 ratios
              >I believe. Hopefully that helps some.
              >
              >I used a SPST toggle to simulate the tactile sensor. When I
              >threw the switch and reset it the bot would continue in
              >reverse almost 1.5 times in a circle before resuming
              >forward. I replaced the 10uF cap with a 1uF cap and now it
              >reverses about 45 deg and goes back to normal.
              >
              >Now... the problem: While the bot it mobile it doesn't ever
              >go photophillic. I figure it has something to do with the
              >LED (not the FLED) not lighting up? The voltage will easily
              >exceed 5V. I don't know what to do. Any help appreciated!
              >
              >
              >
              >
            • Jack
              The LED never comes on. The FLED only flashes. Dimly at that. I ve tried different LEDs and settled on a low-current one that doesn t take much to be visable.
              Message 6 of 12 , Sep 22, 2010
                The LED never comes on. The FLED only flashes. Dimly at that. I've tried different LEDs and settled on a low-current one that doesn't take much to be visable. I swear the cathode is hooked up to pin 2 on the '240. I even tried different caps and FLEDs out of frustration. Just more info for you.

                --- In beam@yahoogroups.com, wrigter <wrigter@...> wrote:
                >
                > To slow the switching between the two motors when the LDRs
                > are equally illuminated, insert a 1M resistor between the
                > LDR midpoint and 240 pins 15/17.
                >
                > The LED should be on while charging. Can you confirm this?
                >
                > wilf
                >
                > ----- Original Message -----
                > From: "Jack" <grsshpr875@...>
                > To: beam@yahoogroups.com
                > Subject: [beam] Re: Maxibug v3 input needed
                > Date: Tue, 21 Sep 2010 22:04:21 -0000
                >
                > >An update and a possible problem...
                > >
                > >The update: Got the bug to work on the breadboard and motor
                > >around with the power of the sun. I found I'll need ~300mA
                > >to make it overcome shady conditions and using an 8V panel
                > >should be enough.
                > >
                > >I haven't done the zener voltage regulation yet (still
                > >haven't gotten the fat 1W resistor for it).
                > >
                > >The platform I've made uses Solarbotics GM17s and it moves
                > >predictably slow. When the CdS cells are at almost equal
                > >resistance both motors experience whiny-power-sucking-228:1
                > >jitter and the bot almost comes to a halt. I'm going to try
                > >the GM17 gear set from Didel that has 51:1 and 100:1 ratios
                > >I believe. Hopefully that helps some.
                > >
                > >I used a SPST toggle to simulate the tactile sensor. When I
                > >threw the switch and reset it the bot would continue in
                > >reverse almost 1.5 times in a circle before resuming
                > >forward. I replaced the 10uF cap with a 1uF cap and now it
                > >reverses about 45 deg and goes back to normal.
                > >
                > >Now... the problem: While the bot it mobile it doesn't ever
                > >go photophillic. I figure it has something to do with the
                > >LED (not the FLED) not lighting up? The voltage will easily
                > >exceed 5V. I don't know what to do. Any help appreciated!
                > >
                > >
                > >
                > >
                >
              • wrigter
                I will breadboard it and we can compare notes. Wilf ... From: Jack To: beam@yahoogroups.com Subject: [beam] Re: Maxibug v3 input needed
                Message 7 of 12 , Sep 22, 2010
                  I will breadboard it and we can compare notes.

                  Wilf
                  ----- Original Message -----
                  From: "Jack" <grsshpr875@...>
                  To: beam@yahoogroups.com
                  Subject: [beam] Re: Maxibug v3 input needed
                  Date: Wed, 22 Sep 2010 15:24:25 -0000

                  >The LED never comes on. The FLED only flashes. Dimly at
                  >that. I've tried different LEDs and settled on a
                  >low-current one that doesn't take much to be visable. I
                  >swear the cathode is hooked up to pin 2 on the '240. I even
                  >tried different caps and FLEDs out of frustration. Just
                  >more info for you.
                  >
                  >--- In beam@yahoogroups.com, wrigter <wrigter@...> wrote:
                  >>
                  >> To slow the switching between the two motors when the
                  >> LDRs are equally illuminated, insert a 1M resistor
                  >> between the LDR midpoint and 240 pins 15/17.
                  >>
                  >> The LED should be on while charging. Can you confirm
                  >> this?
                  >> wilf
                  >>
                  >> ----- Original Message -----
                  >> From: "Jack" <grsshpr875@...>
                  >> To: beam@yahoogroups.com
                  >> Subject: [beam] Re: Maxibug v3 input needed
                  >> Date: Tue, 21 Sep 2010 22:04:21 -0000
                  >>
                  >> >An update and a possible problem...
                  >> >
                  >> >The update: Got the bug to work on the breadboard and
                  >> >motor around with the power of the sun. I found I'll
                  >> >need ~300mA to make it overcome shady conditions and
                  >> >using an 8V panel should be enough.
                  >> >
                  >> >I haven't done the zener voltage regulation yet (still
                  >> >haven't gotten the fat 1W resistor for it).
                  >> >
                  >> >The platform I've made uses Solarbotics GM17s and it
                  >> >moves predictably slow. When the CdS cells are at almost
                  >> >equal resistance both motors experience
                  >> >whiny-power-sucking-228:1 jitter and the bot almost
                  >> >comes to a halt. I'm going to try the GM17 gear set from
                  >> >Didel that has 51:1 and 100:1 ratios I believe.
                  >> >Hopefully that helps some.
                  >> >I used a SPST toggle to simulate the tactile sensor.
                  >> >When I threw the switch and reset it the bot would
                  >> >continue in reverse almost 1.5 times in a circle before
                  >> >resuming forward. I replaced the 10uF cap with a 1uF cap
                  >> >and now it reverses about 45 deg and goes back to
                  >> >normal.
                  >> >Now... the problem: While the bot it mobile it doesn't
                  >> >ever go photophillic. I figure it has something to do
                  >> >with the LED (not the FLED) not lighting up? The voltage
                  >> >will easily exceed 5V. I don't know what to do. Any help
                  >> >appreciated!
                  >> >
                  >> >
                  >> >
                  >>
                  >
                  >
                  >
                • Jack
                  Many thanks for your time, Wilf. To my shegrin I must admit to solving the phillic/phobic problem; it was a motor wiring issue :grimace: The circuit behaves as
                  Message 8 of 12 , Sep 22, 2010

                    Many thanks for your time, Wilf. To my shegrin I must admit to solving the phillic/phobic problem; it was a motor wiring issue :grimace: The circuit behaves as originally described. The LED still doesn't light up but everything else works nicely.

                    Forgive me but I'm not sure I understand the remedy for the jitter. In my mind I read it like this. It doesn't seem to have an effect, for better or worse.

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

                    >
                    > I will breadboard it and we can compare notes.
                    >
                    > Wilf
                    > ----- Original Message -----
                    > From: "Jack" grsshpr875@...
                    > To: beam@yahoogroups.com
                    > Subject: [beam] Re: Maxibug v3 input needed
                    > Date: Wed, 22 Sep 2010 15:24:25 -0000
                    >
                    > >The LED never comes on. The FLED only flashes. Dimly at
                    > >that. I've tried different LEDs and settled on a
                    > >low-current one that doesn't take much to be visable. I
                    > >swear the cathode is hooked up to pin 2 on the '240. I even
                    > >tried different caps and FLEDs out of frustration. Just
                    > >more info for you.
                    > >
                    > >--- In beam@yahoogroups.com, wrigter wrigter@ wrote:
                    > >>
                    > >> To slow the switching between the two motors when the
                    > >> LDRs are equally illuminated, insert a 1M resistor
                    > >> between the LDR midpoint and 240 pins 15/17.
                    > >>
                    > >> The LED should be on while charging. Can you confirm
                    > >> this?
                    > >> wilf
                    > >>
                    > >> ----- Original Message -----
                    > >> From: "Jack" grsshpr875@
                    > >> To: beam@yahoogroups.com
                    > >> Subject: [beam] Re: Maxibug v3 input needed
                    > >> Date: Tue, 21 Sep 2010 22:04:21 -0000
                    > >>
                    > >> >An update and a possible problem...
                    > >> >
                    > >> >The update: Got the bug to work on the breadboard and
                    > >> >motor around with the power of the sun. I found I'll
                    > >> >need ~300mA to make it overcome shady conditions and
                    > >> >using an 8V panel should be enough.
                    > >> >
                    > >> >I haven't done the zener voltage regulation yet (still
                    > >> >haven't gotten the fat 1W resistor for it).
                    > >> >
                    > >> >The platform I've made uses Solarbotics GM17s and it
                    > >> >moves predictably slow. When the CdS cells are at almost
                    > >> >equal resistance both motors experience
                    > >> >whiny-power-sucking-228:1 jitter and the bot almost
                    > >> >comes to a halt. I'm going to try the GM17 gear set from
                    > >> >Didel that has 51:1 and 100:1 ratios I believe.
                    > >> >Hopefully that helps some.
                    > >> >I used a SPST toggle to simulate the tactile sensor.
                    > >> >When I threw the switch and reset it the bot would
                    > >> >continue in reverse almost 1.5 times in a circle before
                    > >> >resuming forward. I replaced the 10uF cap with a 1uF cap
                    > >> >and now it reverses about 45 deg and goes back to
                    > >> >normal.
                    > >> >Now... the problem: While the bot it mobile it doesn't
                    > >> >ever go photophillic. I figure it has something to do
                    > >> >with the LED (not the FLED) not lighting up? The voltage
                    > >> >will easily exceed 5V. I don't know what to do. Any help
                    > >> >appreciated!
                    > >> >
                    > >> >
                    > >> >
                    > >>
                    > >
                    > >
                    > >
                    >

                  • wrigter
                    The schematic has several errors: 1. add a jumper between the negative side of C2 (the reverse cap) and the tactile sensor. When the sesnor closes, the cap is
                    Message 9 of 12 , Sep 22, 2010
                      The schematic has several errors:

                      1. add a jumper between the negative side of C2 (the reverse
                      cap) and the tactile sensor. When the sesnor closes, the cap
                      is charged up through the contact and when the sensor opens
                      the cap is discharged through R2.
                      2. remove the jumper between the U1A output and the U1C/E
                      outputs.
                      3. LDR CDS2 should be connected to the output of U1A instead
                      of to the input of U1E.
                      4. The inputs of U1C and U1E should be connected together.
                      5. The new 1M resistor should go between the common point of
                      the LDRs and inputs of U1C/E.
                      6. A 0.1uf cap should be connected between the inputs of
                      U1C/E and the output pins of U1D/F

                      wilf



                      ----- Original Message -----
                      From: "Jack" <grsshpr875@...>
                      To: beam@yahoogroups.com
                      Subject: [beam] Re: Maxibug v3 input needed
                      Date: Wed, 22 Sep 2010 19:10:55 -0000

                      >Many thanks for your time, Wilf. To my shegrin I must admit
                      >to solving the phillic/phobic problem; it was a motor
                      >wiring issue :grimace: The circuit behaves as originally
                      >described. The LED still doesn't light up but everything
                      >else works nicely.
                      >
                      >Forgive me but I'm not sure I understand the remedy for the
                      >jitter. In my mind I read it like this.
                      ><http://xa.yimg.com/kq/groups/518175/sn/1492068992/name/max
                      >i-1M-balancer\ .jpg> It doesn't seem to have an effect,
                      >for better or worse.
                      >
                      > --- In beam@yahoogroups.com, wrigter <wrigter@...> wrote:
                      >>
                      >> I will breadboard it and we can compare notes.
                      >>
                      >> Wilf
                      >> ----- Original Message -----
                      >> From: "Jack" grsshpr875@...
                      >> To: beam@yahoogroups.com
                      >> Subject: [beam] Re: Maxibug v3 input needed
                      >> Date: Wed, 22 Sep 2010 15:24:25 -0000
                      >>
                      >> >The LED never comes on. The FLED only flashes. Dimly at
                      >> >that. I've tried different LEDs and settled on a
                      >> >low-current one that doesn't take much to be visable. I
                      >> >swear the cathode is hooked up to pin 2 on the '240. I
                      >> >even tried different caps and FLEDs out of frustration.
                      >> >Just more info for you.
                      >> >
                      >> >--- In beam@yahoogroups.com, wrigter wrigter@ wrote:
                      >> >>
                      >> >> To slow the switching between the two motors when the
                      >> >> LDRs are equally illuminated, insert a 1M resistor
                      >> >> between the LDR midpoint and 240 pins 15/17.
                      >> >>
                      >> >> The LED should be on while charging. Can you confirm
                      >> >> this?
                      >> >> wilf
                      >> >>
                      >> >> ----- Original Message -----
                      >> >> From: "Jack" grsshpr875@
                      >> >> To: beam@yahoogroups.com
                      >> >> Subject: [beam] Re: Maxibug v3 input needed
                      >> >> Date: Tue, 21 Sep 2010 22:04:21 -0000
                      >> >>
                      >> >> >An update and a possible problem...
                      >> >> >
                      >> >> >The update: Got the bug to work on the breadboard and
                      >> >> >motor around with the power of the sun. I found I'll
                      >> >> >need ~300mA to make it overcome shady conditions and
                      >> >> >using an 8V panel should be enough.
                      >> >> >
                      >> >> >I haven't done the zener voltage regulation yet
                      >> >> >(still haven't gotten the fat 1W resistor for it).
                      >> >> >
                      >> >> >The platform I've made uses Solarbotics GM17s and it
                      >> >> >moves predictably slow. When the CdS cells are at
                      >> >> >almost equal resistance both motors experience
                      >> >> >whiny-power-sucking-228:1 jitter and the bot almost
                      >> >> >comes to a halt. I'm going to try the GM17 gear set
                      >> >> >from Didel that has 51:1 and 100:1 ratios I believe.
                      >> >> >Hopefully that helps some.
                      >> >> >I used a SPST toggle to simulate the tactile sensor.
                      >> >> >When I threw the switch and reset it the bot would
                      >> >> >continue in reverse almost 1.5 times in a circle
                      >> >> >before resuming forward. I replaced the 10uF cap with
                      >> >> >a 1uF cap and now it reverses about 45 deg and goes
                      >> >> >back to normal.
                      >> >> >Now... the problem: While the bot it mobile it
                      >> >> >doesn't ever go photophillic. I figure it has
                      >> >> >something to do with the LED (not the FLED) not
                      >> >> >lighting up? The voltage will easily exceed 5V. I
                      >> >> >don't know what to do. Any help appreciated!
                      >> >> >
                      >> >> >
                      >> >> >
                      >> >>
                      >> >
                      >> >
                      >> >
                      >>
                      >
                      >
                      >
                    • Jack
                      ... Holy, you aren t kidding! Fortunately I ve been working off another schematic. This EAGLE version was drawn up hastily for posting purposes. ... The 1M
                      Message 10 of 12 , Sep 22, 2010

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

                        >
                        > The schematic has several errors:
                        >
                        > 1. add a jumper between the negative side of C2 (the reverse
                        > cap) and the tactile sensor. When the sesnor closes, the cap
                        > is charged up through the contact and when the sensor opens
                        > the cap is discharged through R2.
                        > 2. remove the jumper between the U1A output and the U1C/E
                        > outputs.
                        > 3. LDR CDS2 should be connected to the output of U1A instead
                        > of to the input of U1E.
                        > 4. The inputs of U1C and U1E should be connected together.

                         

                        Holy, you aren't kidding! Fortunately I've been working off another schematic. This EAGLE version was drawn up hastily for posting purposes.

                         

                        > 5. The new 1M resistor should go between the common point of
                        > the LDRs and inputs of U1C/E.
                        > 6. A 0.1uf cap should be connected between the inputs of
                        > U1C/E and the output pins of U1D/F

                         

                        The 1M resistor works like a charm. No more jitter. Movement straight forward is smooth as butter.

                        The 0.1uF cap has me confused. Again, my interpretation of your instructions here.  When the cap is connected the bot only wheels around in one direction regardless of light levels. Besides that I feel the bot is ready for a few pics and a video :)

                      • wrigter
                        You had me wondering Jack. The positive feedback cap value together with the 1M resistor should be tuned to the time constant of acceleration (determined by
                        Message 11 of 12 , Sep 22, 2010
                          You had me wondering Jack.

                          The positive feedback cap value together with the 1M
                          resistor should be tuned to the time constant of
                          acceleration (determined by robot mass and motor speed) so
                          that it results in a little wiggle as it moves in straight
                          line. If the cap is too big, the wiggle will be too big or
                          the bot may even twirl. With no feedback cap and no resistor
                          there is probably high frequency switching back and forth
                          of the motor drive signals which could be wasteful of
                          energy. With no feedback cap (and stray capacitance alone),
                          the resistor will help lower the frequency of the switching
                          but may not be optimum for efficiency. Experiment for best
                          results.

                          Wilf

                          ----- Original Message -----
                          From: "Jack" <grsshpr875@...>
                          To: beam@yahoogroups.com
                          Subject: [beam] Re: Maxibug v3 input needed
                          Date: Wed, 22 Sep 2010 23:25:39 -0000

                          >--- In beam@yahoogroups.com <mailto:beam@yahoogroups.com> ,
                          >wrigter <wrigter@...> wrote:
                          >>
                          >> The schematic has several errors:
                          >>
                          >> 1. add a jumper between the negative side of C2 (the
                          >> reverse cap) and the tactile sensor. When the sesnor
                          >> closes, the cap is charged up through the contact and
                          >> when the sensor opens the cap is discharged through R2.
                          >> 2. remove the jumper between the U1A output and the U1C/E
                          >> outputs.
                          >> 3. LDR CDS2 should be connected to the output of U1A
                          >> instead of to the input of U1E.
                          >> 4. The inputs of U1C and U1E should be connected
                          >together.
                          >
                          >
                          >
                          >Holy, you aren't kidding! Fortunately I've been working off
                          >another schematic. This EAGLE version was drawn up hastily
                          >for posting purposes.
                          >
                          >
                          >
                          >> 5. The new 1M resistor should go between the common point
                          >> of the LDRs and inputs of U1C/E.
                          >> 6. A 0.1uf cap should be connected between the inputs of
                          >> U1C/E and the output pins of U1D/F
                          >
                          >
                          >
                          >The 1M resistor works like a charm. No more jitter.
                          >Movement straight forward is smooth as butter.
                          >
                          >The 0.1uF cap has me confused. Again, my interpretation of
                          >your instructions here.
                          ><http://xa.yimg.com/kq/groups/518175/sn/1117442670/name/max
                          >i-1M-balancer\ -v2.jpg> When the cap is connected the bot
                          >only wheels around in one direction regardless of light
                          >levels. Besides that I feel the bot is ready for a few pics
                          >and a video :)
                          >
                          >
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