Gas Engine Driven Battery Charger

[wsmurdoch]

Do you know what make and model alternator your Chinese alternator is a clone of?

Bill

[RaymondR]

Hi Bill,

Other than the voltage and Ampere rating there was no information on the box. The auto electrician I purchased it from is a very knowledgeable fellow and I will be visiting him next week to see if he knows of a different regulator with a voltage input terminal.

[wsmurdoch]

The reason I asked is that I have with little trouble brought out the field wire form General Motors CS-130 and CS-130D alternators and used them on my boat. Both are type P alternators with the internal regulator on the positive side of the field (rotor) coil and were easy to do. With the field wire out a host of opportunities become available -- $500 computer controlled external regulators, $50 Ford external regulators, a rheostat, or a string of light bulbs -- to control the alternator output. It would get you around the problem of not having a sensing terminal.

If you have one of the Delco N type alternators, download a pdf copy of "The 12V Doctor's Alternator Book" and look at page 52 (1986 ed). With a silicon diode you can increase the output voltage by 0.5V for about $0.50. Also, pages 105 and 106 may give you a leg up.

Talk to your auto electrician about it. The guys can be magicians.

Bill

[Sternwake]

My Vehicle comes with an externally regulated alternator. I've bypassed the regulator inside engine computer and use an adjustable external VR.

No idea what vehicles in the Aussie market also have external regulation.

My vehicle specs 2 different style of alternators

https://www.amazon.com/Quality-Built.../dp/B000ESDDK2


I bought this one^ model when the Autoparts store refused to acknowledge I ever purchased an alternator from them, but they had warrantied it at least 5 times in the previous 15 years so I was not really butthurt.

It does not do as well at hot idle speeds as the one which failed, but the failed one had the lower brush bridging both slip rings, I've modified thebrush holder to lower the brushes and rehoned the slip rings and plan to return it to service.

I thought the dual internal fan of the Nippon Denso design would be better, but the Chrysler/Bosch 50/120 does better at hot idle than the NipponDenso 50/120:

https://www.autozone.com/external-en...61301_490751_0

Perhaps it is the slightly bigger diameter of the latter, or the external fan, or both.

I use a transpo540HD regulator, about 25$ on Ebay. I added heatsinking and a 60mm fan to it. I also removed the original trimpot, soldered wires to the legs and use a 10 turn bourns potentiometer( 2K ohm)

I can get it to achieve the full 120 amp rating at about 2200+ engine rpm, and use a K type thermocouple thermo epoxied to the casing and dial it back if it starts exceeding 170f.

Soon I will have some data on the field current sent to the rotor. I'm kind of wondering if the older regulator was cumulatively damaged by the one brush barely touching both slip rings. The Alternator only stopped working once the brush wore enough to hit the gap between slip rings. I have a second transpo 540HD ready to go to test that theory. Should do that right now.

[RaymondR]

Hi again Bill,

I have done the regulator bypass as you suggest on the Niko alternator on my old boat's Yanmar and used a 12V motor speed controller to adjust the excitation. It worked well however I was amazed at how much carbon it deposited inside the engine box. I have also used diodes in the voltage sense terminal of the regulator to boost the output and bike spokes in series in the discharge as high wattage resistors to limit alternator output.

I learned an awful lot about alternators from the 12 Volt Doctors Handbook and would not be without a copy of it on the boat.

Hi Sternwake,

You sound like a person I could hold many technical conversations with.

Once I burned out the Niko alternator on my previous boat I had modified the mountings to use Bosch Universal 85 Amp alternators and mounted two of them, one for the cranking and one for the house systems which I completely isolated from each other. Since the Bosch regulators had a voltage sensing terminal I could manipulate the output by varying the sense voltage.

The fan on the 130 Amp alternator is running backwards because of the way I have belt drives it and whilst it appears to provide sufficient cooling whilst the alternator output is only 65 Amps. I will need to do something about it before I start drawing more from it. I am pondering putting a smaller pulley on it and making an oversized fan from 3 mm alloy whilst at it.