Regulate to 13.8 Volts

[Robert Reed]

Mr Al
I can only do this by regular E-Mail with an attachment (Jpeg). Since the format change recently, I don't seem to be able to PM or EM from this site, I can't even get my own profile as a syntax error keeps popping up. Until I get this resolved If you and Sam would just supply me with your E-Mail adress I could shoot this out to you. Maybe you can get through with PM to me if you want to keep it off the forum.

[ecerfoglio]

It will be a 3 phase motor and I will update my schematic to show that. There are two ways to wire it up thou... STAR or DELTA.. I believe you find more Star configurations for Windmill applications.. so I will try that first.

Alternators are (almost) allways wired in a STAR configuration.

There is a good reason for it:

As the rotor moves, each winding "sees" a variable magnetic field. In an ideal machine, that variation is sinusoidal and so the generated EMF is also sinusoidal.

But a in a "real" alternator there are allways harmonics present.

If the windings are simetrical, there are little (or no) even ordered harmonics present.

But the odd ordered ones (3, 5, 7, ...) are allways there. Of course, the third order harmonic is the biggest of them.

In a delta wired machine, that third order harmonic EMF has a low impedance path (arround the three windings) and so creates a current that lowers the machine's efficiency.

If the machine is wired in a star (or "Y") there are no internal closed circuits, and so there is no 3rd harmonic current. Moreover, if you connect only the three "live" wires to the load (no neutral) the 3rd harmonic voltage will cancel out and will not be present in the output.

[Chris Smith]

For the engineering already designed into each alternator, there is no comparison to the lowely alternator.

Its dirt cheap, it has the bearings, the windings, the regulator and the case plus the mounts already designed in,.... its repairable for even less, and well, its 100% proven for the last 4 decades or more so starting with the alternator saves any one from reinventing the wheel.

A big plus.

[MrAl]

Hi again,

Chris,
I've used an alternator once a long long time ago to create
a battery charger. The alternator ran off of a 120vac motor
with a pully and belt system.

Have any idea what the minimum speed of rotation might be
to get the alternator to put out some decent current ?

[Robert Reed]

Mr AL
The manufacturers say that their alternators charge even at engine idle speeds. Engine idle approx 600 rpm - don't know what the alternator rpm is at that speed due to belt/pulley variations.

[Chris Smith]

We were taught a life time ago 1100 rpms I believe is the actually pulley speed of the alternator. [Full production "starts" here]

Im experimenting as well with a 55 amp alternator and the wind, and so I used a ten speed bike rim matched to the pulley using something like 100 inch belt. [High rpm gain]


My next experiment [4 of them] will be the vane type like a kids pin wheel, not the blade types just yet. Just three long strips on an axis.

My first experiment was the anemometer type blade using three satellite dishes and 8 foot arms made out of aluminum. They are self starting but its low to the ground and I don’t have anywhere to place it yet. It works best in a high wind. Our wind is erratic.

I also have a prop from a air plane for another, and finally we have plenty of 5 foot wind generators from the farm watering systems of old. I just need to rebuild one from several broken ones.

I have several 55 amp foreign and domestic, as well as the 100 amp domestic alternator.

Because the alternator is capable of producing over 600 watts of power full speed, you don’t have to run it at full speed or the high Rpms to produce a usable amount of power.

You can remove the regulator and engage the coils full time and then place in a series of diodes for the DC, running the alternator slower and with a Zener to clamp any excess voltage, and using the battery as a partial shunt regulator. You will produce a few amps and volts, and some will clamp to zero, but you will produce power. You can judge the speed VS amps and make adjustments.

You started off with 600 watts, fifty five amps, now you easily produce a few amps like five or even ten.

What happens is the slower speed will still produce enough voltage [ way over 12] with a small amount of amperage, the Zener will ensure the set voltage is no more than 14 volts, and the battery will clamp and absorb the rest.

My final design will be the unregulated voltage and frequency fed into a heater element of 750 watts. [normally 120 v x 60 Hz x 6.25 amps or 750 watts]

Now its 120 variable volts X Variable HZ x 600 or variable watts max into a resistor that dosent care what the values are, it just produces some or a lot of heat as it is a dead short.

The voltage will float with the wind speed in winter adding in plain heat when the wind blows, which normally robs the place of some of its heat from the blowing cold wind.

The whole system will self regulate because the Heater [Resistor] Element can take the full voltage and amperage, [the frequency is irrelevant] and a little more so it wont burn out at 600 watts max when its designed for 750 w.

[MrAl]

Hello again

Ok guys, sounds good.
It was a very long time ago i built that charger.

Also ran a automobile air conditioner compressor (from a circa 1960
Cadillac convertible) from a 120vac motor, with the 12vdc clutch
driven from 120vac with bridge rect and 50 watt (or 100watt) light
bulb in series to drop the voltage. The compressor was used to
compress air into an old water tank to use with a paint sprayer. Since
those compressors have 4 dual acting pistons it worked pretty well with a
little oil now and then.

[Chris Smith]

I still have a 55 amp alternator and AC in one unit, powered by a 120 volt motor. It will put out the PSI but its way too slow.

My brother converted his AC unit in the van complete with a air tank for the same concept, only it was mobile.

Great for tires and dusting out the Motor Cross Bike parts at the race.

[Robert Reed]

Hello Sam
Did you get my PM and/or E-Mail regarding the charger print? I saw that I had a PM from you that you had not received it at that time (prior to recent mailings).