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Re: [Electronics_101] Re: Got Lights?

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  • Stefan Trethan
    a simple diode isn t going to work. you need a current limiter. is the big ground and the small ground connected? (chassis or so) you will need a series
    Message 1 of 24 , Apr 1, 2004
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      a simple diode isn't going to work.
      you need a current limiter.

      is the "big ground" and the small ground connected? (chassis or so)

      you will need a series transistor....

      ST


      On Fri, 02 Apr 2004 03:17:20 -0000, kphenix500 <kphenix500@...>
      wrote:

      > Thanks gentlemen for your response. I posted pics in the photo
      > section under Ken's Toy. This is a "mini" sand rail (less than
      > 600lbs) and is powered by a motorcycle engine producing around 80hp.
      > The alternator or stator is encased in the engine's side cover and
      > cannot be replaced. there is a company known as Ricky Stator that
      > rewinds motorcycle & ATV stators to increase their output.
      > Unfortunately mine is already operating at peak output and cannot be
      > enhanced. It is a fairly common practice with this type vehicle to
      > add an external automotive alternator but it is generally driven off
      > the final drive and not the crankshaft. Consiquently the alternator
      > is only producing power when the vehicle is moving and it also robs
      > horespower. You could almost use the light switch for brakes. Just
      > joking. Anyway, these are some of the reasons why I chose the aux
      > battery setup instead. Bill Darden @ batteryfaq.org says I may be
      > able to connect a diode isolator between the 2 batteries. If this
      > sounds viable, I need help finding the proper value diode to let no
      > more than 2 amps pass through. Thanks again for your advice.
      > -ken
      >
      > --- In Electronics_101@yahoogroups.com, "kphenix500"
      > <kphenix500@y...> wrote:
      >> Hey guys, I need help. I need to locate or get advice on how to
      >> build a device to safely (2 amps max) charge a U1 category power
      >> chair battery by connecting to a 12v automotive/motorcycle
      >> electrical system. It sounds pretty simple but I have yet to find
      > a
      >> company that offers anything like this. I don't know much about
      >> electronics - I'm learning by the despiration method. I have a
      >> motorcycle powered mini sand buggy that I built from scatch.
      >> Unfortunately, the motor's stator only produces 23 to 27 amps -
      > not
      >> nearly enough to power the 370 watt off road lighting system I'm
      >> using. I am using an Interstate DCS33 battery on the lights in
      >> isolation. This setup provides several hours of nighttime duning
      >> pleasure. The downside is that I must remove the 30lb battery to
      >> charge it. I'd like to have a way to charge on the fly. Any ideas?
      >> -ken
      >
      >
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    • Steve
      Dave, I don t think you understand how an alternator and regulator work. It controls both the voltage -and- current, so it s possible to draw, say, 60A at
      Message 2 of 24 , Apr 2, 2004
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        Dave, I don't think you understand how an alternator and regulator
        work. It controls both the voltage -and- current, so it's possible to
        draw, say, 60A at 13.8V from idle to full bore.

        A vehicle alternator is a 3 phase AC generator that regulates voltage
        and current by controlling current in the rotor.

        Here's more detail:
        http://www.autosite.com/garage/subsys/bachargs.asp

        To Ken: you don't select a diode to limit current. The alternator's
        regulator handles that. However, I doubt your current alternator is
        going to last long charging two batteries, especially when you are
        adding a load like those lights.

        Why not just find a larger alternator that will fit? And then do the
        same for the main battery?

        Alien Steve

        --- In Electronics_101@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
        wrote:
        ...
        > That said, your altinaotr will generate voltage based on speed and
        > yoru voltage regulator will only pass what is needed. Since you
        > probably can charge the battery at idle, high RPM is time spend not
        > using the generated power. And by the looks of your photos, that
        > does not idle very often.
        >
        > Ergo, you should be able to see much higher voltages as the motor RPM
        > increases and with the higher voltages, you should be able to deliver
        > higher watts.
        >
        > Since the voltage regulator is designed to limit voltage to the
        > battery at somewhere around 14.7 volts, it is cutting off the power
        > most of the time.
        >
        > The trick would be to run unfettered at the higher voltages and pull
        > off what you can.
        >
        > A multi stage voltage regulator might allow you to let the voltage
        > run up to 30 volts and then use that to charge the battery.
        >
        > Also, you don't really need all 300 watts. If you are getting a few
        > hours of run time, charging with 150 watts would increase your time
        > considderably.
        ...
      • Stefan Trethan
        he just wants to partially charge the second batt. (not refill all current the lamps draw.) when he turns off the lamps it can charge fully. you need only
        Message 3 of 24 , Apr 2, 2004
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          he just wants to partially charge the second batt.
          (not refill all current the lamps draw.)
          when he turns off the lamps it can charge fully.

          you need only limit the current, the voltage is set by the present
          regulator.
          when the big battery is full the new current regulator will have almost
          zero drop.
          when the big battery is empty the current regulator has enough drop to
          keep the current
          at 2A (or whatever wanted).

          a vehicle "voltage regulator" only regulates voltage, by changing the
          rotor current.
          it does NOT regulate the current in any way.

          (believe me i have built one for my car with temperature compensation and
          all (winter))

          st


          On Fri, 02 Apr 2004 15:58:22 -0000, Steve <alienrelics@...> wrote:

          > Dave, I don't think you understand how an alternator and regulator
          > work. It controls both the voltage -and- current, so it's possible to
          > draw, say, 60A at 13.8V from idle to full bore.
          >
          > A vehicle alternator is a 3 phase AC generator that regulates voltage
          > and current by controlling current in the rotor.
          >
          > Here's more detail:
          > http://www.autosite.com/garage/subsys/bachargs.asp
          >
          > To Ken: you don't select a diode to limit current. The alternator's
          > regulator handles that. However, I doubt your current alternator is
          > going to last long charging two batteries, especially when you are
          > adding a load like those lights.
          >
          > Why not just find a larger alternator that will fit? And then do the
          > same for the main battery?
          >
          > Alien Steve
          >
          > --- In Electronics_101@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
          > wrote:
          > ...
          >> That said, your altinaotr will generate voltage based on speed and
          >> yoru voltage regulator will only pass what is needed. Since you
          >> probably can charge the battery at idle, high RPM is time spend not
          >> using the generated power. And by the looks of your photos, that
          >> does not idle very often.
          >>
          >> Ergo, you should be able to see much higher voltages as the motor RPM
          >> increases and with the higher voltages, you should be able to deliver
          >> higher watts.
          >>
          >> Since the voltage regulator is designed to limit voltage to the
          >> battery at somewhere around 14.7 volts, it is cutting off the power
          >> most of the time.
          >>
          >> The trick would be to run unfettered at the higher voltages and pull
          >> off what you can.
          >>
          >> A multi stage voltage regulator might allow you to let the voltage
          >> run up to 30 volts and then use that to charge the battery.
          >>
          >> Also, you don't really need all 300 watts. If you are getting a few
          >> hours of run time, charging with 150 watts would increase your time
          >> considderably.
          > ...
          >
          >
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          >
          > To visit your group on the web, go to:
          > http://groups.yahoo.com/group/Electronics_101/
          >
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          > Electronics_101-unsubscribe@yahoogroups.com
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        • manifold
          Motorcycle regulator/alternator sets are a little more primitive. The end of the crankshaft has the alternator rotor attached to it which is a set of permanent
          Message 4 of 24 , Apr 2, 2004
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            Motorcycle regulator/alternator sets are a little more primitive. The
            end of the crankshaft has the alternator rotor attached to it which is
            a set of permanent magnets. There is a three phase stator around it
            and the regulator schematics that I have seen use SCRs to control the
            pulse times to the battery.

            I assume it is a phase angle triggered circuit but I am not sure where
            the current limiting comes from. I do know that I have burned up a few
            stators on various motorcycles usually because the regulator
            overcharged the battery and it dried it out within a few months. After
            replaceing the water in the battery and push starting it for a few
            weeks, gosh, the stator was bad. I rewound it and it worked. Twice.

            I would go ahead and try connecting the batteries the same way that RV
            batteries are connected and see if it works. Do RV's use a simple
            diode to isolate the systems? It probably will be fine and the
            secondary battery will get some charge from the engine alternator and
            it will not burn up because you keep water in your batteries :)

            It will still put extra drag on your engine while the batteries are
            charging and when your lights are on. The good news is that you may be
            able to use a smaller lighter secondary battery.

            Are you using tungsten lights? How about getting more efficient lights
            that take less power?



            --- In Electronics_101@yahoogroups.com, "Steve" <alienrelics@y...> wrote:
            > Dave, I don't think you understand how an alternator and regulator
            > work. It controls both the voltage -and- current, so it's possible to
            > draw, say, 60A at 13.8V from idle to full bore.
            >
            > A vehicle alternator is a 3 phase AC generator that regulates voltage
            > and current by controlling current in the rotor.
            >
            > Here's more detail:
            > http://www.autosite.com/garage/subsys/bachargs.asp
            >
            > To Ken: you don't select a diode to limit current. The alternator's
            > regulator handles that. However, I doubt your current alternator is
            > going to last long charging two batteries, especially when you are
            > adding a load like those lights.
            >
            > Why not just find a larger alternator that will fit? And then do the
            > same for the main battery?
            >
            > Alien Steve
            >
            > --- In Electronics_101@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
            > wrote:
            > ...
            > > That said, your altinaotr will generate voltage based on speed and
            > > yoru voltage regulator will only pass what is needed. Since you
            > > probably can charge the battery at idle, high RPM is time spend not
            > > using the generated power. And by the looks of your photos, that
            > > does not idle very often.
            > >
            > > Ergo, you should be able to see much higher voltages as the motor RPM
            > > increases and with the higher voltages, you should be able to deliver
            > > higher watts.
            > >
            > > Since the voltage regulator is designed to limit voltage to the
            > > battery at somewhere around 14.7 volts, it is cutting off the power
            > > most of the time.
            > >
            > > The trick would be to run unfettered at the higher voltages and pull
            > > off what you can.
            > >
            > > A multi stage voltage regulator might allow you to let the voltage
            > > run up to 30 volts and then use that to charge the battery.
            > >
            > > Also, you don't really need all 300 watts. If you are getting a few
            > > hours of run time, charging with 150 watts would increase your time
            > > considderably.
            > ...
          • Dave Mucha
            Ok, I ll be the first to admit I don t know how the alternator works, but it seems that speed of rotation and energy used to create rotation should equal
            Message 5 of 24 , Apr 2, 2004
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              Ok, I'll be the first to admit I don't know how the alternator works,
              but it seems that speed of rotation and energy used to create
              rotation should equal energy out.

              So, either the unit uses some hp at idle and some fraction thereof at
              high RPM, or something else is at play.

              If the alternator can power a typical vehicle at idle, then the
              available power at 3x that rpm should offer 3x that power.

              The voltage regulator would seem to limit the voltage output. so
              that if the alternator output at 700 RPM is 15 volts, the it would go
              to logic that 45 volts would be possible at 2,100 RPM.

              If the unit were to use 1hp of motor power at idle, then the total
              energy at high RPM should be 3x that at idle ?

              I am only speculating, but it seems that the goal is to limit voltage
              to 15volts or less regardless of RPM. If watts followed RPM, then
              the delivered amps would ramp with RPM.

              I am wondering if the accepted thinking is to limit voltage to the
              level needed to charge the battery, and not to pull as much power as
              possible.


              I mean that it takes something along the lines of 11 hp to keep a
              luxury car moving at 55 mph, but the car has a 350 hp engine.
              Similarly, the maximum domestic car has a watt load of all lights,
              radio and ignition, so if the generating loop can supply that at
              idle, it seems to follow that the availabe power at high RPM would be
              much greater.

              Of course, I may be missing something but hopefully, someone will
              point out where I am going wrong.

              Dave
            • Roy J. Tellason
              ... Would this by any chance have been a battery that sat over the winter without being maintained at full charge? That was the reason I used to sell so darn
              Message 6 of 24 , Apr 2, 2004
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                On Friday 02 April 2004 02:57 pm, manifold wrote:
                > Motorcycle regulator/alternator sets are a little more primitive. The
                > end of the crankshaft has the alternator rotor attached to it which is
                > a set of permanent magnets. There is a three phase stator around it
                > and the regulator schematics that I have seen use SCRs to control the
                > pulse times to the battery.
                >
                > I assume it is a phase angle triggered circuit but I am not sure where
                > the current limiting comes from. I do know that I have burned up a few
                > stators on various motorcycles usually because the regulator
                > overcharged the battery and it dried it out within a few months. After
                > replaceing the water in the battery and push starting it for a few
                > weeks, gosh, the stator was bad. I rewound it and it worked. Twice.

                Would this by any chance have been a battery that sat over the winter without
                being maintained at full charge? That was the reason I used to sell so darn
                many of the things each spring, along with garden tractor batteries, and
                trolling motor batteries, though not all at the same time...

                > I would go ahead and try connecting the batteries the same way that RV
                > batteries are connected and see if it works. Do RV's use a simple
                > diode to isolate the systems?

                An isolator is actually two diodes, common anode connection to the output of
                the alternator, and the cathodes going to each battery.

                > It probably will be fine and the secondary battery will get some charge from
                > the engine alternator and it will not burn up because you keep water in your
                > batteries :)

                Maybe, depending on how much of the time that alternator is expected to
                deliver power. They do get hot, and are probably not rated to put out 100%
                of the time.
              • Roy J. Tellason
                ... Yeah, up to a point, but... ... Available power? Yeah. ... Why do you assume that as RPMs go up the _voltage_ goes up too? ... Not necessarily. ... To
                Message 7 of 24 , Apr 2, 2004
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                  On Friday 02 April 2004 09:16 pm, Dave Mucha wrote:
                  > Ok, I'll be the first to admit I don't know how the alternator works,
                  > but it seems that speed of rotation and energy used to create
                  > rotation should equal energy out.

                  Yeah, up to a point, but...

                  > So, either the unit uses some hp at idle and some fraction thereof at
                  > high RPM, or something else is at play.
                  >
                  > If the alternator can power a typical vehicle at idle, then the
                  > available power at 3x that rpm should offer 3x that power.

                  Available power? Yeah.

                  > The voltage regulator would seem to limit the voltage output. so
                  > that if the alternator output at 700 RPM is 15 volts, the it would go
                  > to logic that 45 volts would be possible at 2,100 RPM.

                  Why do you assume that as RPMs go up the _voltage_ goes up too?

                  > If the unit were to use 1hp of motor power at idle, then the total
                  > energy at high RPM should be 3x that at idle ?

                  Not necessarily.

                  > I am only speculating, but it seems that the goal is to limit voltage
                  > to 15volts or less regardless of RPM. If watts followed RPM, then
                  > the delivered amps would ramp with RPM.

                  To some extent this is true. I've had a number of cars with ammeters in them,
                  and right after you start up it is fairly common to see that meter swing a
                  little further over when you were giving it some gas. This was only right
                  after you started it, and did moderate pretty quickly as the battery was
                  brought back to full charge.

                  > I am wondering if the accepted thinking is to limit voltage to the
                  > level needed to charge the battery, and not to pull as much power as
                  > possible.

                  The vehicles in question were all Chrysler products. These had three
                  terminals on the alternator, plus ground. One was the output, and was tied
                  to the ignition circuit (and therefore to the battery when the switch was
                  on). The other two were the field coil, and were fed varying amounts of
                  power at a varying duty cycle as determined by the voltage regulator. The
                  regulator was a three-terminal device as well, one of which was tied to the
                  ignition circuit to monitor the battery voltage, and the other of which fed
                  the field coil terminal of the alternator.

                  I don't know how they did it in vehicles with idiot lights or in those setups
                  where the regulator is inside the alternator, which seems to be pretty
                  common with GM products and probably some others.

                  > I mean that it takes something along the lines of 11 hp to keep a
                  > luxury car moving at 55 mph, but the car has a 350 hp engine.
                  > Similarly, the maximum domestic car has a watt load of all lights,
                  > radio and ignition, so if the generating loop can supply that at
                  > idle, it seems to follow that the availabe power at high RPM would be
                  > much greater.

                  Yeah, it's _possible_ to get an alternator to kick out much more power when
                  it's needed, but I doubt that this happens much of the time.

                  > Of course, I may be missing something but hopefully, someone will
                  > point out where I am going wrong.

                  Hope this helps some.
                • Stefan Trethan
                  correct.... when i have headlights and ventilation on in my car at idle the voltage drops to 13V or so. The field wind in the rotor is then on full bore.
                  Message 8 of 24 , Apr 2, 2004
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                    correct....

                    when i have headlights and ventilation on in my car at idle the voltage
                    drops to 13V or so.
                    The field wind in the rotor is then on full bore.

                    slightly more rpm and all is fine... 15V when cold..

                    when running on high rpm the field wind will nearly be off....

                    you should not remove the regulator and connect field to full on,
                    because then the power will be too big at rpm (resistive losses)
                    and your alternator will burn.

                    (also your battery will boil a hole in the car)


                    ST


                    (Note: if you have trouble with the car electrics build a expanded scale
                    voltmeter that plugs into the cigarette lighter plug. good to know the
                    voltage...)

                    On Sat, 03 Apr 2004 02:16:00 -0000, Dave Mucha <dave_mucha@...>
                    wrote:

                    >
                    > Ok, I'll be the first to admit I don't know how the alternator works,
                    > but it seems that speed of rotation and energy used to create
                    > rotation should equal energy out.
                    >
                    > So, either the unit uses some hp at idle and some fraction thereof at
                    > high RPM, or something else is at play.
                    >
                    > If the alternator can power a typical vehicle at idle, then the
                    > available power at 3x that rpm should offer 3x that power.
                    >
                    > The voltage regulator would seem to limit the voltage output. so
                    > that if the alternator output at 700 RPM is 15 volts, the it would go
                    > to logic that 45 volts would be possible at 2,100 RPM.
                    >
                    > If the unit were to use 1hp of motor power at idle, then the total
                    > energy at high RPM should be 3x that at idle ?
                    >
                    > I am only speculating, but it seems that the goal is to limit voltage
                    > to 15volts or less regardless of RPM. If watts followed RPM, then
                    > the delivered amps would ramp with RPM.
                    >
                    > I am wondering if the accepted thinking is to limit voltage to the
                    > level needed to charge the battery, and not to pull as much power as
                    > possible.
                    >
                    >
                    > I mean that it takes something along the lines of 11 hp to keep a
                    > luxury car moving at 55 mph, but the car has a 350 hp engine.
                    > Similarly, the maximum domestic car has a watt load of all lights,
                    > radio and ignition, so if the generating loop can supply that at
                    > idle, it seems to follow that the availabe power at high RPM would be
                    > much greater.
                    >
                    > Of course, I may be missing something but hopefully, someone will
                    > point out where I am going wrong.
                    >
                    > Dave
                    >
                    >
                    >
                    >
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                  • Dave Mucha
                    ... voltage ... http://www.autosite.com/garage/subsys/bachar01.asp#Chap1 ======================================================== All charging systems use the
                    Message 9 of 24 , Apr 3, 2004
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                      --- In Electronics_101@yahoogroups.com, Stefan Trethan
                      <stefan_trethan@g...> wrote:
                      > correct....
                      >
                      > when i have headlights and ventilation on in my car at idle the
                      voltage
                      > drops to 13V or so.
                      > The field wind in the rotor is then on full bore.
                      >
                      > slightly more rpm and all is fine... 15V when cold..
                      >
                      > when running on high rpm the field wind will nearly be off....
                      >
                      > you should not remove the regulator and connect field to full on,
                      > because then the power will be too big at rpm (resistive losses)
                      > and your alternator will burn.
                      >
                      > (also your battery will boil a hole in the car)



                      http://www.autosite.com/garage/subsys/bachar01.asp#Chap1
                      ========================================================
                      "All charging systems use the principle of electromagnetic induction
                      to generate electrical power. Electromagnetic principle states that a
                      voltage will be produced if motion between a conductor and a magnetic
                      field occurs. The amount of voltage produced is affected by:

                      #1 The speed at which the conductor passes through the magnetic
                      field.
                      #2 The strength of the magnetic field.
                      #3 The number of conductors passing through the magnetic field. "
                      =================================================================


                      From this we can establish that RPM varies so #1 does vary.
                      #2 may be a function of the voltage regulator, or it may be a fixed
                      value.
                      #3 is a constant on any given device.


                      The whole idea is that the alternator spun at some fixed ratio to the
                      motor. Lower motor RPM= lower alternator RPM = lower output voltage.

                      The voltage regulator is designed to maintain a voltage very close to
                      a constant. Remove the regulator and you have nothing more than
                      coils rotating in a housing. Adding the electrical field to the
                      windings and you then have coils rotating in a magnetic field and
                      that will generate voltage in proportion to RPM.

                      More RPM = More voltage

                      I totally agree that if one allows the voltage to increase, the
                      battery will boil.

                      Also, the coils rotating in the magnetic field can be used as a brake
                      or at least a major drag on the motor.

                      If the alternator can produce 100watts at 12 volts, we can deduce
                      that we are seeing 8.33 amps.

                      If the alternator were to spin 3x is seems that voltage should
                      increase 3x (without being regulated to a constant voltage) so that
                      the alternator would deliver a higher value, I assume it is linear.

                      So a motor at idle around 700 RPM vs a motor at 2,100 RPM would drive
                      the alternator to possibly 36 volts ? Same 8.33 amps would yeild 300
                      watts.

                      Figure volts times amps / 746 = hp and you rob the motor of roughly 5
                      hp.

                      Not enough to stall the motor, but enough to know the lights are on.

                      Like I said before, I don't know enough about alternators and it
                      *may* be the voltage regulator alters the magnetic field so as to
                      maintain the voltage.

                      But unless there is something else going on, the principal of faster
                      = more would stand.

                      How to use 36 volts on 12 volt lights is another matter.

                      Dave
                    • Steve
                      ... wrote: ... Well, that -is- what we ve been saying. The strength of the magnetic field is changed by changing the current in the rotor. Do you understand
                      Message 10 of 24 , Apr 3, 2004
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                        --- In Electronics_101@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
                        wrote:

                        ...
                        > Like I said before, I don't know enough about alternators and it
                        > *may* be the voltage regulator alters the magnetic field so as to
                        > maintain the voltage.

                        Well, that -is- what we've been saying. The strength of the magnetic
                        field is changed by changing the current in the rotor.

                        Do you understand that there is no permanent magnet in a standard
                        vehicle alternator? And that the power is -not- drawn from the rotor?
                        Power is drawn from 3 phases of coils in the stator.

                        The magnetic field is created in the rotor by a current through a
                        winding on it. Rotor spins, generates 3 phases of current/voltage in
                        the stator windings. Goes through 3 phase rectifier.

                        Regulator has basically three limits: a max voltage out, max current
                        out, and a max current into the rotor winding. The max current into
                        the rotor winding limits power available at low RPMs. If it did not
                        have this limit, it would likely burn up the rotor slip rings and
                        windings. As for max current out, alternators are designed with a duty
                        cycle in mind. As normally they must put out a lot more current when
                        the vehicle is first started to recharge the battery.

                        Alien Steve
                      • Stefan Trethan
                        ... DEFINITELY. all common car alternators (ac) i have seen use a field coil in the rotor. the voltage regulator output variable is the current through this
                        Message 11 of 24 , Apr 3, 2004
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                          > Like I said before, I don't know enough about alternators and it
                          > *may* be the voltage regulator alters the magnetic field so as to
                          > maintain the voltage.

                          DEFINITELY.

                          all common car alternators (ac) i have seen use a field coil in the rotor.
                          the voltage regulator output variable is the current through this coil.

                          (the voltage regulator does not work like a linear regulator or so in the
                          power lines,
                          it is only connected to the alternator output for sensing - there is no
                          voltage drop or
                          so across the regulator)

                          >
                          > But unless there is something else going on, the principal of faster
                          > = more would stand.


                          principle seems correct, you could draw more watts, but not more ampere.
                          i too dunno how to use tha additional volts...

                          However, this is a motorcycle generator, which seems entirely different.

                          It has permanent magnets, so constant field.
                          the voltage (or battery charge) is regulated via phase angle control of
                          the alternator
                          main output. (this means the current is conntrolled and the battery acts
                          as buffer).

                          I see two possibilities to charge the big battery:

                          version a)

                          a current regulator directing a certain, fixed amount of current from the
                          small battery to the big
                          battery, this current would go through the existing regulator also of
                          course.

                          version b)

                          find the wires from the generator, before the existing regulator, and add
                          a second regulator, which
                          charges the big battery at a low maximum rate (2A or so).
                          you maybe could use another part of the waveform than the existing
                          regulator and thus decrease the
                          resisitive losses / increase useable power without more heating of the
                          alternator.

                          Version B would be technically better, but much more sophisticated than
                          version A.
                          I would try version b, and most likely have a look if i can add safety
                          things like
                          overtemperature protection of the alternator.
                          For a beginner i would recommend version A, a current limiting transistor
                          is not that hard to
                          build and it can be debugged without a scope...

                          Stefan


                          >
                          > How to use 36 volts on 12 volt lights is another matter.
                          >
                          > Dave
                          >
                          >
                          >
                          >
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                        • Stefan Trethan
                          ... correct for CAR, seems in a motorcycle it is permanent magnets and scr phase angle control of main current. the buggy in question has a motorcycle engine.
                          Message 12 of 24 , Apr 3, 2004
                          • 0 Attachment
                            > Well, that -is- what we've been saying. The strength of the magnetic
                            > field is changed by changing the current in the rotor.
                            >
                            > Do you understand that there is no permanent magnet in a standard
                            > vehicle alternator? And that the power is -not- drawn from the rotor?
                            > Power is drawn from 3 phases of coils in the stator.
                            >
                            > Alien Steve
                            >
                            >

                            correct for CAR,

                            seems in a motorcycle it is permanent magnets and scr phase angle control
                            of main current.

                            the buggy in question has a motorcycle engine.

                            ST
                          • MAX Alarm
                            O.K. guys..let me put some lights on youre discusion...myne yob is car electric..if we speak about normal alternator produced somewhere about 1990-1998...there
                            Message 13 of 24 , Apr 3, 2004
                            • 0 Attachment
                              O.K. guys..let me put some lights on youre discusion...myne yob is car electric..if we speak about normal alternator produced somewhere about 1990-1998...there is voltage regulator inside alternator...you have windings on stator directly conected on set of diodes and this are for charging baterys..
                              another windings are on rotor ..rotor wind.is drived via voltage regulator  on most cars regulation is via pulse duration because resistance of rotor are  2-6 ohm..
                              so rotor are polarised and you have strong mag.field ..if voltage start rising about 14.6 regulator shut off curent to rotor..when vol.drop below 12.9  it switch rotor again..and all this is work in cycles..
                              if youre car have abs / air cond. this is treshold (14.3) on most european car..
                              older car without all this work 12.8-13.5...
                               
                              another important stuff related to charging is CURENT but again voltage regulator adjust polarisation on rotor wind...
                               
                               
                              sory for my bad english but I hope I help you...
                              ----- Original Message -----
                              From: Steve
                              Sent: Saturday, April 03, 2004 3:09 PM
                              Subject: [Electronics_101] Re: Got Lights? alternator and voltage regulator

                              --- In Electronics_101@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
                              wrote:

                              ...
                              > Like I said before, I don't know enough about alternators and it
                              > *may* be the voltage regulator alters the magnetic field so as to
                              > maintain the voltage.

                              Well, that -is- what we've been saying. The strength of the magnetic
                              field is changed by changing the current in the rotor.

                              Do you understand that there is no permanent magnet in a standard
                              vehicle alternator? And that the power is -not- drawn from the rotor?
                              Power is drawn from 3 phases of coils in the stator.

                              The magnetic field is created in the rotor by a current through a
                              winding on it. Rotor spins, generates 3 phases of current/voltage in
                              the stator windings. Goes through 3 phase rectifier.

                              Regulator has basically three limits: a max voltage out, max current
                              out, and a max current into the rotor winding. The max current into
                              the rotor winding limits power available at low RPMs. If it did not
                              have this limit, it would likely burn up the rotor slip rings and
                              windings. As for max current out, alternators are designed with a duty
                              cycle in mind. As normally they must put out a lot more current when
                              the vehicle is first started to recharge the battery.

                              Alien Steve

                            • Stefan Trethan
                              On Sat, 3 Apr 2004 15:23:15 +0200, MAX Alarm ... it s the same as we are saying it all time. of course you could also control the
                              Message 14 of 24 , Apr 3, 2004
                              • 0 Attachment
                                On Sat, 3 Apr 2004 15:23:15 +0200, MAX Alarm <stjepan.vukic@...>
                                wrote:

                                > O.K. guys..let me put some lights on youre discusion...myne yob is car
                                > electric..if we speak about normal alternator produced somewhere about
                                > 1990-1998...there is voltage regulator inside alternator...you have
                                > windings on stator directly conected on set of diodes and this are for
                                > charging baterys..
                                > another windings are on rotor ..rotor wind.is drived via voltage
                                > regulator on most cars regulation is via pulse duration because
                                > resistance of rotor are 2-6 ohm..
                                > so rotor are polarised and you have strong mag.field ..if voltage start
                                > rising about 14.6 regulator shut off curent to rotor..when vol.drop
                                > below 12.9 it switch rotor again..and all this is work in cycles..
                                > if youre car have abs / air cond. this is treshold (14.3) on most
                                > european car..
                                > older car without all this work 12.8-13.5...
                                >
                                > another important stuff related to charging is CURENT but again voltage
                                > regulator adjust polarisation on rotor wind...
                                >
                                >
                                > sory for my bad english but I hope I help you...


                                it's the same as we are saying it all time.
                                of course you could also control the current in the field wind linear, not
                                pulse width.

                                ST
                              • Dave Mucha
                                ... ... rotor? ... I do realize that the alternator is contorlled by a variable magnetic field and that the generally accepted limits of such
                                Message 15 of 24 , Apr 3, 2004
                                • 0 Attachment
                                  --- In Electronics_101@yahoogroups.com, "Steve" <alienrelics@y...>
                                  wrote:
                                  > --- In Electronics_101@yahoogroups.com, "Dave Mucha"
                                  <dave_mucha@y...>
                                  > wrote:
                                  >
                                  > ...
                                  > > Like I said before, I don't know enough about alternators and it
                                  > > *may* be the voltage regulator alters the magnetic field so as to
                                  > > maintain the voltage.
                                  >
                                  > Well, that -is- what we've been saying. The strength of the magnetic
                                  > field is changed by changing the current in the rotor.
                                  >
                                  > Do you understand that there is no permanent magnet in a standard
                                  > vehicle alternator? And that the power is -not- drawn from the
                                  rotor?
                                  > Power is drawn from 3 phases of coils in the stator.
                                  >
                                  > The magnetic field is created in the rotor by a current through a
                                  > winding on it. Rotor spins, generates 3 phases of current/voltage in
                                  > the stator windings. Goes through 3 phase rectifier.


                                  I do realize that the alternator is contorlled by a variable magnetic
                                  field and that the generally accepted limits of such a device is left
                                  to the manufactures data sheets, but.....

                                  We are trying to figure a way to do something off the mainstream.

                                  If we agree that amps will have some simple limit, but voltage can
                                  vary, it may be possible to get a lot more watts from an alternator
                                  than one would ever need for any common applications.

                                  One thing that comes to mind is 'fooling' the VR by loading it to
                                  maintain something less than it's upper limit. That would allow it
                                  to deliver peak power, and I assume more power, at higher revolutions.

                                  Alternatly, if one were to use a higher voltage and get higher watts,
                                  then we could look at what would be needed to deliver that as uasable
                                  current at a usable voltage.

                                  IF, (big IF) we could get the alternator to deliver 36volts at the
                                  rated amps, it would be then require handling that higher load and
                                  delivering it at 12 volts.

                                  Dave
                                • Steve
                                  ... control ... Ah... I d missed that. Alien Steve
                                  Message 16 of 24 , Apr 3, 2004
                                  • 0 Attachment
                                    --- In Electronics_101@yahoogroups.com, Stefan Trethan
                                    <stefan_trethan@g...> wrote:
                                    >
                                    > > Well, that -is- what we've been saying. The strength of the magnetic
                                    > > field is changed by changing the current in the rotor.
                                    ...
                                    > correct for CAR,
                                    >
                                    > seems in a motorcycle it is permanent magnets and scr phase angle
                                    control
                                    > of main current.
                                    >
                                    > the buggy in question has a motorcycle engine.

                                    Ah... I'd missed that.

                                    Alien Steve
                                  • MAX Alarm
                                    again me..(car electric) if I need from same alternator bigest voltage I should take another stator(more windings) another rotor(resistance 8-12 ohm) it means
                                    Message 17 of 24 , Apr 3, 2004
                                    • 0 Attachment
                                      again me..(car electric) if I need from same alternator bigest voltage I should take another stator(more windings) another rotor(resistance 8-12 ohm) it means more wind.. and another regulator for higher volt....some years ago I was thinking that similar problem will be solved if yust replace VR but when I put 28 V VR max voltage is about 18-20..so for higher voltage you will need more windings( of course smaler diameter of wires) because you always will have about 300W from this source..it means if you need higher volt you will be less in curent..absolute power from this source ( alternator) depends how big is alternator ...that is from myne praxis ( last 10 years)..
                                       
                                      but for practice ..you can play with VR so use wire for power up VR and measure Voltage on it..you can put some resistors in series with sensitive pin on VR...
                                       
                                      when you pull out Vr from alternator you will see some contact directly on rectifier(diodes plate) this is sensitiv input for VR..so try ...play with voltage divider..and you will see what is max.voltage from youre alternator...TAKE care that screws are GROUND conection for VR so put extra wire for GROUND...
                                       
                                      on one kawasaki motorcycles I measure 32Vdc when VR was dead..(and batery...) 
                                       
                                      do make this experiment when car is conected to alternator  because some car electronic realy dont like any power more than 14vdc...
                                       
                                      If you see gray smoke from alt..it means you fuck up something..buy anoter one and play again...
                                       
                                      ..Regards from Croatia 
                                      ----- Original Message -----
                                      Sent: Saturday, April 03, 2004 6:10 PM
                                      Subject: [Electronics_101] Re: Got Lights? alternator and voltage regulator

                                      --- In Electronics_101@yahoogroups.com, "Steve" <alienrelics@y...>
                                      wrote:
                                      > --- In Electronics_101@yahoogroups.com, "Dave Mucha"
                                      <dave_mucha@y...>
                                      > wrote:
                                      >
                                      > ...
                                      > > Like I said before, I don't know enough about alternators and it
                                      > > *may* be the voltage regulator alters the magnetic field so as to
                                      > > maintain the voltage.
                                      >
                                      > Well, that -is- what we've been saying. The strength of the magnetic
                                      > field is changed by changing the current in the rotor.
                                      >
                                      > Do you understand that there is no permanent magnet in a standard
                                      > vehicle alternator? And that the power is -not- drawn from the
                                      rotor?
                                      > Power is drawn from 3 phases of coils in the stator.
                                      >
                                      > The magnetic field is created in the rotor by a current through a
                                      > winding on it. Rotor spins, generates 3 phases of current/voltage in
                                      > the stator windings. Goes through 3 phase rectifier.


                                      I do realize that the alternator is contorlled by a variable magnetic
                                      field and that the generally accepted limits of such a device is left
                                      to the manufactures data sheets, but.....

                                      We are trying to figure a way to do something off the mainstream.

                                      If we agree that amps will have some simple limit, but voltage can
                                      vary, it may be possible to get a lot more watts from an alternator
                                      than one would ever need for any common applications.

                                      One thing that comes to mind is 'fooling' the VR by loading it to
                                      maintain something less than it's upper limit.  That would allow it
                                      to deliver peak power, and I assume more power, at higher revolutions.

                                      Alternatly, if one were to use a higher voltage and get higher watts,
                                      then we could look at what would be needed to deliver that as uasable
                                      current at a usable voltage.

                                      IF, (big IF) we could get the alternator to deliver 36volts at the
                                      rated amps, it would be then require handling that higher load and
                                      delivering it at 12 volts.

                                      Dave


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