Regulators - what’s the difference

[parrot]

Now I’m not the most electrically minded, but was looking at a Nippondenso KE15 and KE70 alternator regulator yesterday and wondered, what’s the difference?  

I’m guessing it has something to do with the output rating of the alternator?  Certainly some of the wires are a bit bigger on the later regulator.  But these little magic boxes have always puzzled me.  What exactly do they do?
 

 

[ke70dave]

My understanding (maybe right, maybe wrong) is that the issue with alternators is that their output changes with rpm...So the regulator is there to keep it in check across the whole rpm range. Alternator needs to be able to charge the battery from 850rpm (idle) and ~6000rpm (redline) without going over ~14volts (so you dont cook anything)

Now Mr banjo will hopefully chime in here, but i believe the regulator varies the current in the rotor to regulate the output of the alternator. Looks like the current in the rotor is proportional to the current out put of the alternator (wiki gives an example of a 70a alternator may require a 7a rotor current). So perhaps this explains the difference in sizes in wiring you are seeing. 

https://en.wikipedia.org/wiki/Alternator_(automotive)#Field_regulation

 

[parrot]

Water cooled alternators!  I wonder what uses those.  Probably a Bugatti Veyron or some such.  I was working through that and wondered what the field current is, and got onto another page that explained it quite well.

https://alternatorparts.com/understanding-alternators.html#:~:text=ALTERNATOR ROTOR&text=Current through the wire coil,%2FC%2C or direct current.

It actually starts to make sense, sort of.  I seem to recall my old Datsun 1600's had adjustable regulators I vaguely recall twiddling with no idea of what I was doing, and no doubt made things worse.  But at least it turned me to reliable Toyota's

[Banjo]

Hi Pete,

                I could bore you to tears, but this video describes just about everything regarding automotive alternators.

https://youtu.be/jdSKlg80DjU

The only difference you will come across on our Rollas, is that early Rolla's had alternators, where the regulator was a separate unit, & was non electronic.

Later model Rollas have alternators, which have an inbuilt electronic alternator.  Alternators, are generally sized by the maximum load current they can produce.  Maximum electrical load is usually required during night driving, when lights & other electrical loads are at their greatest. One of the best mods you can do to a Rolla, is fit an alternator, with a greater output.

Early model alternators fitted to Rollas, produced 30 - 35- 40 amps max output current.  Best mod I ever did to my KE30 2 door, was to fit a Hilux alternator, with 85 Amp output.  Others on this forum, have used Holden Commodore alternators, with up to 120 amp output.

Cheers Banjo 

[Banjo]

As the u-tube video above relates, the reason we need a big ampere/hour battery, is for just one thing;  to start the car !  Once the car is started, you really only need a quite  small battery, as the power/current consumed by the car once running, is very small, by comparison to starter motor current, which can easily be supplied by a small alternator & smaller battery.

I'm olde enough to remember my dad using a crank handle, to start our Morris straight 6, when it had a flat battery. It not only took a lot of effort, but if it fired & "kicked back", it could really do some damage to your arm or wrist.  The reason the starter motor is large, is that it is working against the  compression in the engine.

Lots of remarks on the net that we only have another 10-15 years, before the demise of  I.C.E. motors.

I read an article recently, in which it claimed the ICE motor is not done with yet, & there are still those developing new features, to prolong it's life. One that caught my attention was a "camless" engine, where the valves are opened by hydraulic pressure, controlled by electronically controlled electric valves. They have built running engines, that rev to 20K rpm, using this technique. One feature that caught my attention was the fact, that the starter motor size could be greatly reduced, & hence the size of the battery.  The technique was that when starting the engine, all valves would be opened except one. Once it kicked in, the other cylinders could be brought on-line, one at a time. 

Crazy when you thing about it, that we lug this very heavy battery around all day, simply so we can simply start the car, when it stops.

https://youtu.be/S3cFfM3r510

https://www.youtube.com/watch?v=Bch5B23_pu0

Cheers Banjo

Edited January 12, 2021 by Banjo