View Full Version : alternator charging

08-24-2008, 05:16 AM
I came across this web page showing how to use a automotive alternator to generate electricity.
http://www.dangerouslaboratories.org/altcharge.html but I would like to control this via a basic stamp.
I thought of using a digital rheostat·but none I've seen can handle the amperage. So how can I do this ?

Post Edited (firewater) : 8/25/2008 1:24:33 AM GMT

08-24-2008, 05:44 AM
I am not sure if this would work, but possibly use a stamp to control a Mosfet with PULSOUT or PWM. The mosfet would control the·rotor windings, using a circuit to sense an amperage draw and an adc to recoginze a low or high battery voltage. When the battery has reached 14.5 vdc, the stamp can shut off the·mosfet controlled rotor windings.

With an amperage circuit, the stamp would be able to maintain an amperage output by increasing Pulsout/PWM to the·rotor windings beyond·break-even point, while the load exsists. The stamp could also be programed to trickle charge·the battery over an extended period.

08-24-2008, 12:17 PM
Find yourself a better circuit. This one seems too complicated to control and prone to failure.

- Stephen

08-24-2008, 01:23 PM
Is there a reason they are telling you to use one without an internal regulator? Because it would be a HECK of a lot simpler to use one with it.

Something circa 89-95 GM would be easiest IMO, the "CS" alternator, available from 80 amps up to 130. There is one connector and an output wire. Connect "S" to the output, ignore "F" and "P" and connect "L" to a 3-4 watt bulb (192 is normal) and then to posistive. This excites the alternator, so you MUST have it connected, and you MUST have resistance in there. If you really wanted to make it compact, just wire a resistor to the output terminal. You will need to juice the alternator before it will start charging, to energize the field coils. So just keep it connected to a 12v battery.

So if you use an internally regulated alternator, you only need one wire to make it work, the output wire. Much, much simpler than that hack fest they have there. In fact they go on and on about how unsafe it is and how you have to babysit it. I have no idea why they would do this. If you are not going to have a battery, you could probably hook up a small 12v motor with a hand crank or something to energize the fields. That or get a small 12v battery, or a just a bunch of AA's, you only need to kick the fields before they will take over.

Also, keep in mind the power curve of the alternator when selecting pulleys and power sources. Alternators dont really make any power below 2500 RPM, and thier peak is usually much higher. If you buy a reman one, it will come with a test sheet, which will give you a good idea.

Again, I dont know what you are doing, but automotive alternators dont make very good generators for wind or "renewable" energy sources because of thier active fields and high RPMs. Consider motorcycle alternators, they are usually perminant magnet.

08-25-2008, 03:26 AM
while it might be far easier to use the internally regulated one wire delco such as the cs130

in my opinion that is doomed to failure! the internally regulated alternator if hooked to a substantial battery bank

will never be useful for the following reasons.

1. the hp required to drive it is substantial and without control over the charging you are forced to compromise

between gearing it down enough to have the hp to drive it when the battery is low, and driving it fast enough to provide for

low rpm when the battery is nearing full charge.

2. the cs130 is a dreadful machine for the diy'er to work on, the oem regulator is very poor for charging true deepcycle batteries

3. the life expectancy is going to be short if you ask for max output, and have enough hp to drive it.

4. there is no provision in an automotive alternator for temperature compensation, so you will either cook your batteries

or undercharge them.

so the link addresses some of these issues by compromising the automatic nature of a regulator,, you are the regulator with that


take a look at a balmar controller such as the mc612 and it will become clear what is needed and why it is needed, and next it will become clar

that a microcontroller could be used to do what they have done. depending on how good you are with your design and what it is you want to do will determine your success.

you might want to study how an automotive regulator works, it is a pwm control scheme (analog) and i see no reason one could not impliment

some digital control into it.

just such a controller is on my list of modules to produce using the bs2

bob g

Dream it, design it, engineer it, build it, and

do what is necessary to make the damn thing work!

09-03-2008, 12:47 AM
GICU812, I don't know if the author of the link I provided intended it as an early experiment related to inventor Stanley Meyer's Water Fuel Cell (WFC) but it does just that.

Electrical Polarization Process
Amp Inhibiting Circuit
WFC U.S. Patent Validation Report
U.S. Patent Application; S/N 6/302,807 Filed Sept 16, 1981
Natural Water Hydrogen Generation System

Page 18
"Other amp restricting circuits are,
also, applicable such as applying a variable (0-5) volts unipolar pulse frequency across the
armature field-winding of a de-regulated alternator functioning as a pulse-voltage frequency
generator, as so illustrated in Photo Exhibits 11B, 11B1, and 11C."

Large file be very patient:
http://www.waterfuelcell.org/ForumPDFs/International%20Independent%20Test%20Evaluation%20 Report.pdf

09-07-2008, 07:06 AM
Firewater,U need to controll the Exciter windings of the ALT....The current for the (field windings) are small compared to the ALT. output current. Also note that an AUTO. type ALT. is 3 Phase AC, This makes Rect. to DC EZer w/ half wave Rect.s; The BS2 will Reg. an ALT. W/ no problem. You'll need to go from TTL level voltage(+5v) to Auto voltage(+13.8v).I'd use the IRF511 Nchannel MOSFET. The reson for this is the IRF511 is fully SATR. @ 5volts this is the output voltage of the stamp$.w/ this the stamp$ can SW/ 13.8 volts(the fully charge state of a car battery) w/ just 5volts from the stamp$.Use " PULSOUT " statment.This is a PWM output the duty cycle and freq. are controlled in the PULSOUT statment.(see pg. 146 of the BS2$ stamp$works Manuel) also pg.347 of(BS2$ Syntax and Refef. Manuel) for some light on "PUSLOUT"...This is Me all day long,short and sweet......Next You'll need some feed back from the ALT.s output..I'd use the ADC0831, this is an A/D converter,(you'll have to hold this chip(ADC0831) +10 volts above ground. This will give a range of +0 to +5 volts (+10 to +15 volts to ground) {{{!!!^^----___DO NOT APPLY MORE THAN_!!!+5VOLTS!!!_TO A I/O PIN ON THE $BS2x___^^!!!}}}}}
Doing so will let all the factory smoke out, and it can not be replaced!!!!!!!!!!!!!!!...Next a " DO-LOOP "or a " GOSUB-RETURN "
W/ an " IF-THEN-ELSE" statment will control the dutycycle% in the "PULSOUT" statment........If you need some more info or help w/ something,Drop a post reply,,I try to checkin the FORUMs every night...............___%WMc$___out__!!!!!!!!!!!!!