[SOLVED] Voltage regulator inside a Bosch car alternator

Hello Everyone!

Can anyone please tell me which voltage regulator[part number] is present inside a Bosch Car Alternator?

I guess it is some kind of linear voltage regulator.

As far as I know the alternator need to run at very high speed to produce output suitable for charging 12V car battery.

What is the rotation speed range?

manishanand14 said:

Hello Everyone!

Can anyone please tell me which voltage regulator[part number] is present inside a Bosch Car Alternator?

I guess it is some kind of linear voltage regulator.

As far as I know the alternator need to run at very high speed to produce output suitable for charging 12V car battery.

What is the rotation speed range?

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What exactly model ? There is different types. Todays alternators have digital control and they are water cooled.

Alternators need 750rpm and up to produce power. Full power of alternator is reached on highest RPM of engine, at lower engine rpm you get small power from it. With newer car this is different.

Its special high power voltage regulator dedicated to usage in car alternators, also the same is with alternator diodes.

Todays EU cars alternators can produce 100-200A just like some big city bus. With increasing of electricity demands in cars alternators are improved to be stronger and better. Just see difference between digital AC in newer car and old car with old dumb AC inside.

Rotation speed of alternators depends from car to car, and alternator construction. Directly rotation speed depends from ration of pulley on engine and alternator. Strong sports rally cars can have up to 10000rpm of alternator. On older car alternator pulley is changed with smaller to get higher rpm at lower rpm of engine, to provide apropriate charging of battery in only city driving. With new idiotic traffic laws older cars cant never recharge batteries to full state, because mandatory lights on. More results will have to prohibit production of cars with black and darken colors.





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Thanks for the reply.

I asked this question in a very general way to acquaint myself with the voltage regulator inside it.

Can you please tell me what may be the voltage and the current output of the alternator.I guess the current output will depend on the speed of the engine.

I guess the voltage regulator in the old ones [first diagram you have posted]must be a linear regulator.Then it must be wasting a lot of power.If we use a switched mode regulator,can we not improve the efficiency of the alternator.

Can you please send me the link to the data sheet of some of the popular and easily available car alternators.

Voltage of alternator depends from alternator regulator in other words from alternator model. It is usually 14,4V-14,2V on alternator, but on batterz terminals no more then 13,8V or you will have thirsty battery.

Without regler voltage goes to 15V and more, and voltage is related direct from rpm of engine and can go to 17-19V.

Also without battery voltage will have strong peaks up to 40V which can kill fine electronics in car.


If you whant better efficiency try newer car.

Can you please send me the link to the data sheet of some of the popular and easily available car alternators.

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I dont think that this will not be from some significance, because you are from India, and I'm in Europe. I mean on "easy available".

All depends from car which alternator to use. I have in Golf 2 VR6 150A alternator (almost for welding :-D). But you cant put that in some car with weak engine like 1.1 or 1.3. You need power to rotate alternator, it takes in full strenght up several HP for normal cars (55-65A), you see what will happen with 120A or higher with smaller engine. There is systems for welding in field with alternators powered by small fuel engine, or car engine.

There is one other story about battery capacity in car. Should put bigger or smaller battery inside or leave it like factory. But this is just other story.

:wink:

If I couple the alternator with the rear wheel of a bicycle via a belt and If I pedal @ 30rpm I guess I will be getting 12V output regulated.

I wish to store the energy in a supercap[100F or higher,15V rated bank] for small duration.I mean i want to pedal for say 5 minutes and store the energy generated in a supercap bank and then gradually discharge to power small loads.

Can you please tell me the feasibility of this basic concept.

manishanand14 said:

If I couple the alternator with the rear wheel of a bicycle via a belt and If I pedal @ 30rpm I guess I will be getting 12V output regulated.

I wish to store the energy in a supercap[100F or higher,15V rated bank] for small duration.I mean i want to pedal for say 5 minutes and store the energy generated in a supercap bank and then gradually discharge to power small loads.

Can you please tell me the feasibility of this basic concept.

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Oooo, ooo easy :shock:, You cant do that, humans body is not that strong on longer roads. Average humans dont have needed power to rotate energised alternator. That alternator must be modified to use permanent strong magnets in rotor to generate magnetic field. Standard alternator use electricity in rotor to make magnetic field, but resistance will occur, and situation will worse on higher electricity load on alternator. Ration should be high, pedal wheel should be bigger say 21" and alternator wheel should be smaller.


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See this video with supercap tv and console, I can post only one video per post :

https://www.youtube.com/watch?v=3LzcGXHjpdM&playnext=1&list=PL8834A9F0DFE9ED17&feature=results_main

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If you whant to charge battery, there is one way you need sun, focused reflector, gas in pipe and stearling engine. This is used to make ice bricks without nothing just gas in closed pipes and sun. But this is other story.

So will a 12V PMDC will be a better choice instead of alternator.

All depends from what you whant to do with electricity. All conversions have loses.


Did you see DIY variants of alternators for wind generators ? Several amperes at low speed of rotation. :wink:

thanks for all the replies

No prob I'm glad to help You.