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seuadr,
I have seen similar thoughts like this and you are actually looking at exactly what bothered me right at the beginning when I first looked at the charging system. I have read up on it quite a bit and I now have come to understand why we are stuck with it. If you will bear with me I will just mention them:
1) Our bikes have a 3 phase AC alternator with a full wave rectifier bridge. These bridges are rated at anything from a couple of Amps mostly up to 35 Amps for the larger bikes. You can do the maths in calculating what the RMS voltage would give you after rectification and that will be your DC max voltage before regulation. This output is also directly related to the RPM's of the alternator and is sometimes the factor most overlooked. It cannot put out maximum current at low RPM's and when people look at this they forget that this. Thus we also want enough current to keep the bike and battery alive at low speeds as well.
2) The regulator uses SCR's that shunt the excess current once a preset voltage is reached, such as say 14.2 V (these regulators differ by design between 13.8 V to 15.1 Volt as the regulation voltage). Again the SCRs are current rated to match the bridge and may be the same or slightly higher than the bridge. A field regulated alternator kicks in earlier at low RPM's and usually provides a steady 13.8V throughout.
3) Small and large bikes can both have the same size 18 pole alternator (or any other size) as an example, but the windings could differ. Thus the maximum current is dependant on the maximum rating of the alternater (usually given in Watts), say 22 Amp or 28 Amp for example.
4) The Rectifier/Regulator of a smaller bike and thus a lower output alternator will be matched so that the R/R does not exceed its rating, overheat and fail. Thus a larger R/R on a low output alternator will just provide a larger safety factor and the R/R will not be stressed and may last longer. It will not provide more current.
5) Fitting an stronger alternator usually means that more copper and heavier wire is used. Just keep in mind that there is very limited space for more copper. There is always a tradeoff, heavier windings fill the space with less windings and thus lower AC voltage. Thinner wire allow more windings, higher AC voltage. This you can look at yourself. More current, more heat etc. You also do not want to run the motor at 10 000 RPM before making any usefull current! It is a bit nicer if you can cruise in traffic with lights on, at low RPM without draining your battery.
6) Series or linear regulators do not work on a bike, it is claimed that more heat is generated in the components, thus requiring much larger and expensive regulators. Many people question this and I have seen many theories. I think this is a subject on its own.
7) Shunt regulators as we know them now, have been used since the late 70's by each and every M/C manufacturer right up to today. If there really was another and better way someone would have followed that path already. I think that many high tech R & D's have alreadly looked at this and found this to be the best option cost wise, easy to manufacture and takes up the least space. By the way I have noticed that Shindengen have now brought out a FET instead of SCR shunt regulator, 50 Amp rating.
8) The ideal power generating system is the standard car type alternator with a field winding regulating the output voltage, thus not using permanent magnets and some top end bikes already use this - Goldwing etc. There is thus no unused current that has to be absorbed somewhere as heat and for starters the regulators are not heavy duty like ours.
9) What this all means is that the actual space and size limitations will be one of the main reasons for sticking to this old method, then comes cost as well. Unfortunately it is not a bullet proof design as the regulator can easily be build to weld with, but the stator windings remain the achilles heel. One needs to get an alternator out into some cooling air and use field winding regulation and then you can literally weld with an alternator.
10) It thus boils down to the fact that no matter what we do we cannot get more amps from our bikes than what the stator can give and that is due to the size and space limitation. You can only upgrade the stator slightly and in the process you are most likely compromising the safety factor which will then manifest itself a bit sooner. Thus if you ever do upgrade your charging system and maybe squeeze out an extra 20 or 30 watts, remember to upgrade your regulator as well.
11) On a smaller bike, yes, you could use an upgraded alternater, to specs of the larger bikes, but you MUST then also put in a larger regulator and most of then are only rated maximum 35 Amp. This will still limit you to very much the same load you already have on the larger bikes and will not give you the capability to add foglights or a 200W HF radio other than very low current extras.
As you can see we are really very much stuck with what we have and the best way is to ensure that everything is in perfect condition, alternator, wiring, battery and regulator. Reduce the current hungry loads as far as possible by fitting LED's or maybe HID headlights (35 watt). Maintain your battery well and enjoy the GS.
As you can see I am no electronics fundi, and gave it as I see and understand it. If I made some non-scientific statements in error then I apologise and do not use this at your college as your professor may fail you and I will be to blame!!
Edit: I apologise if I came over rudely in this one, it was not my intention. I just wanted to paint the whole picture from what I have seen to date. Your questioning things like this is admirable and shows an enquiring mind. My intention is or was not to put anyone down that tries to think outside the box! You would most probably be amazed if I could show you all the proposals on changes to our charging systems that people have thought of and then finally saw that it was theoretically good, but not very possible in practice, meaning that I am very open to such innovations and look at them closely for possibilities.
Keep well.
I have seen similar thoughts like this and you are actually looking at exactly what bothered me right at the beginning when I first looked at the charging system. I have read up on it quite a bit and I now have come to understand why we are stuck with it. If you will bear with me I will just mention them:
1) Our bikes have a 3 phase AC alternator with a full wave rectifier bridge. These bridges are rated at anything from a couple of Amps mostly up to 35 Amps for the larger bikes. You can do the maths in calculating what the RMS voltage would give you after rectification and that will be your DC max voltage before regulation. This output is also directly related to the RPM's of the alternator and is sometimes the factor most overlooked. It cannot put out maximum current at low RPM's and when people look at this they forget that this. Thus we also want enough current to keep the bike and battery alive at low speeds as well.
2) The regulator uses SCR's that shunt the excess current once a preset voltage is reached, such as say 14.2 V (these regulators differ by design between 13.8 V to 15.1 Volt as the regulation voltage). Again the SCRs are current rated to match the bridge and may be the same or slightly higher than the bridge. A field regulated alternator kicks in earlier at low RPM's and usually provides a steady 13.8V throughout.
3) Small and large bikes can both have the same size 18 pole alternator (or any other size) as an example, but the windings could differ. Thus the maximum current is dependant on the maximum rating of the alternater (usually given in Watts), say 22 Amp or 28 Amp for example.
4) The Rectifier/Regulator of a smaller bike and thus a lower output alternator will be matched so that the R/R does not exceed its rating, overheat and fail. Thus a larger R/R on a low output alternator will just provide a larger safety factor and the R/R will not be stressed and may last longer. It will not provide more current.
5) Fitting an stronger alternator usually means that more copper and heavier wire is used. Just keep in mind that there is very limited space for more copper. There is always a tradeoff, heavier windings fill the space with less windings and thus lower AC voltage. Thinner wire allow more windings, higher AC voltage. This you can look at yourself. More current, more heat etc. You also do not want to run the motor at 10 000 RPM before making any usefull current! It is a bit nicer if you can cruise in traffic with lights on, at low RPM without draining your battery.
6) Series or linear regulators do not work on a bike, it is claimed that more heat is generated in the components, thus requiring much larger and expensive regulators. Many people question this and I have seen many theories. I think this is a subject on its own.
7) Shunt regulators as we know them now, have been used since the late 70's by each and every M/C manufacturer right up to today. If there really was another and better way someone would have followed that path already. I think that many high tech R & D's have alreadly looked at this and found this to be the best option cost wise, easy to manufacture and takes up the least space. By the way I have noticed that Shindengen have now brought out a FET instead of SCR shunt regulator, 50 Amp rating.
8) The ideal power generating system is the standard car type alternator with a field winding regulating the output voltage, thus not using permanent magnets and some top end bikes already use this - Goldwing etc. There is thus no unused current that has to be absorbed somewhere as heat and for starters the regulators are not heavy duty like ours.
9) What this all means is that the actual space and size limitations will be one of the main reasons for sticking to this old method, then comes cost as well. Unfortunately it is not a bullet proof design as the regulator can easily be build to weld with, but the stator windings remain the achilles heel. One needs to get an alternator out into some cooling air and use field winding regulation and then you can literally weld with an alternator.
10) It thus boils down to the fact that no matter what we do we cannot get more amps from our bikes than what the stator can give and that is due to the size and space limitation. You can only upgrade the stator slightly and in the process you are most likely compromising the safety factor which will then manifest itself a bit sooner. Thus if you ever do upgrade your charging system and maybe squeeze out an extra 20 or 30 watts, remember to upgrade your regulator as well.
11) On a smaller bike, yes, you could use an upgraded alternater, to specs of the larger bikes, but you MUST then also put in a larger regulator and most of then are only rated maximum 35 Amp. This will still limit you to very much the same load you already have on the larger bikes and will not give you the capability to add foglights or a 200W HF radio other than very low current extras.
As you can see we are really very much stuck with what we have and the best way is to ensure that everything is in perfect condition, alternator, wiring, battery and regulator. Reduce the current hungry loads as far as possible by fitting LED's or maybe HID headlights (35 watt). Maintain your battery well and enjoy the GS.
As you can see I am no electronics fundi, and gave it as I see and understand it. If I made some non-scientific statements in error then I apologise and do not use this at your college as your professor may fail you and I will be to blame!!
Edit: I apologise if I came over rudely in this one, it was not my intention. I just wanted to paint the whole picture from what I have seen to date. Your questioning things like this is admirable and shows an enquiring mind. My intention is or was not to put anyone down that tries to think outside the box! You would most probably be amazed if I could show you all the proposals on changes to our charging systems that people have thought of and then finally saw that it was theoretically good, but not very possible in practice, meaning that I am very open to such innovations and look at them closely for possibilities.
Keep well.
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