Author Topic: 12 volt slave setup  (Read 986 times)

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johnnym

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12 volt slave setup
« on: February 03, 2017, 09:02:31 AM »
Someone at Thermodyne finally got back to me and told me If my turbine is rated at 48v and I want it to be 12v I can use a 12v slave setup. What is this?

Adriaan Kragten

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Re: 12 volt slave setup
« Reply #1 on: February 03, 2017, 10:35:44 AM »
I think that it is a DC-DC converter. I know that DC-DC converters exist which transform about 24 DC into 12 DC but might be they also exist for 48V DC to 12V DC.

OperaHouse

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Re: 12 volt slave setup
« Reply #2 on: February 03, 2017, 11:11:17 AM »
I think that is somewhat correct.  A converter will allow a wide range of input voltage and convert that to a set fixed voltage.  I believe the slave is a tracking converter and outputs a DC voltage proportional to the input voltage, much like a transformer does with AC.  Probably a specialty item that won't be found on ebay cheap.

johnnym

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Re: 12 volt slave setup
« Reply #3 on: February 03, 2017, 12:30:35 PM »
If I could go back in time I would have done things differently but I just decided to dive into the deep end.

"This is what he wrote me:

Hi,   You need all 48 volt rated or a 12 volt slave set up

STUDY SLAVING HERE

NEED AN AUTOMATIC POWER REGULATOR FOR YOUR BATTERY? STUDY HERE.

SEA440 VIDEO'S - It's a BATTERY CONTROLLER so the BATTERY really does not care how the power is getting into it, wind, solar,,, atomic, it's all the same to the battery.   When your battery gets full it dumps or cuts your choice.  See both video's, one is on cutting and one on about dumping the excess power.

http://youtu.be/2oNCDbRiXjQ
http://youtu.be/JSusPX734F0
https://youtu.be/rVffRzl6zcY    48Volt

NEED AN AUTOMATIC POWER REGULATOR FOR YOUR BATTERY?

STUDY POWER SLAVING (see diagrams near bottom of web page)
http://www.hydrogenappliances.com/batteryregulator.html
BUY SEA440  HERE
http://www.hydrogenappliances.com/sea400but.html
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=301035093103

IMAGES
http://www.hydrogenappliances.com/SEA440 DUMP MODE 24.jpg
http://www.hydrogenappliances.com/SEA440 CUTMODE24.jpg
http://www.hydrogenappliances.com/SEA440 DUMP MODE 48.jpg
http://www.hydrogenappliances.com/SEA440 CUT MODE 48.jpg
http://www.hydrogenappliances.com/SEA440 CUT MODE .jpg
http://www.hydrogenappliances.com/SEA440 DUMPMODE12.jpg

PROGRAMMING CONTROLLERS ALL MODELS
https://youtu.be/81y50tpSads   G4   P-1 setting  001
https://youtu.be/rVffRzl6zcY    G5   P-1 setting 001
https://www.youtube.com/watch?v=f9_P2rfQzgs
https://www.youtube.com/watch?v=f9_P2rfQzgs
https://www.youtube.com/watch?v=IZRahrogJ_A
https://www.youtube.com/watch?v=NZENiUNoHWo
https://youtu.be/8mAhuEGwlnE "

I think they sell the item but it is not very clear. Hell, the wind is blowing like crazy here today. I just want to finally get this thing set up. Thanks everyone.  :)

kitestrings

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Re: 12 volt slave setup
« Reply #4 on: February 06, 2017, 10:28:11 AM »
Hi J,

Not to discourage you, but I think if I were you, I'd stop and assess what you're trying to do and how best to do it.  Maybe you've done this, but doing a bit of homework would save you a whole lot of frustration down the road.  If you're loads are modest you can probably do what you want with a simple fixed voltage system (12 or 24V likely).  Converters, and strategies to step down, or buck a DC voltage, are do-able but can introduce losses and unnecessary complexity.  And, if you're dumping load, if it is not going to something dependably useful, it is just loss.

I started to watch the first video and left at the point where the author said, "...just want to let you know too about electricity...electricity vibrates people.."  He goes on to explain that it loosens fasteners and terminals.  While this might be true at the molecular level - and that's not my area of expertise - I think what is loosening  his fasteners is the repetitive action of that large starter relay/solenoid.

Some for profit sites post rather ambitious projections for relatively small diameter turbines, and/or talk about unrealistically high usable winds.  They also promote installing them on towers that are too short, or on rooftops.  If you're not familiar with "Betz Limit" you might take a look here:

https://www.ndsu.edu/pubweb/~klemen/Perfect_Turbine.htm

You might enjoy reading some of Hugh Piggott's books, or "The Dans" at Otherpower.  There are a lot of products out there and a lot of them sound too good to be true with good reason.

You might also google what Hugh, Paul Gipe and others have to say about rooftop turbines and small turbines in urban areas.

~ks


Adriaan Kragten

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Re: 12 volt slave setup
« Reply #5 on: February 06, 2017, 12:28:50 PM »
In my report KD 35 I give a derivation of the Betz-coefficient at chapter 4.2. In chapter 4.3 I give the three reasons why the theoretical Cp is lower than the Betz-coefficient, being wake rotation, finite number of blades and airfoil drag. These three effects result in a certain maximum theoretical Cp. However, the effective blade length is shorter than R and using formula 6.3 you find the real maximum Cp. With this Cp you can calculate the maximum mechanical power at the rotor shaft for a certain wind speed if the rotor is loaded such that it turns at the optimum tip speed ratio. But for the generated electrical power you also have to take the transmission efficiency and the generator efficiency into account. If the windmill is used for battery charging, there is only a low rpm range for which the generator efficiency is high. This is because the charging voltage is almost constant and the power only increases by increase of the current. But the copper losses in the generator winding increase strongly at increasing current and the generator efficiency at maximum power is therefore rather low. If the windmill is positioned far from the batteries, you also have certain cable losses in the connecting lines. So the average electrical power is much lower than the mechanical power on the rotor shaft. All these effects together result in a much lower power than derived with the Betz-coefficient. But even if all these effects are taken into account, certain windmills are producing less than that what is possible because rotor and generator are not well matched. This means that the rotor is turning far from the optimum tip speed ratio where the Cp is maximal.

electronbaby

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Re: 12 volt slave setup
« Reply #6 on: February 09, 2017, 07:32:33 PM »
Your 48v turbine will work with a blocking diode (rectifier) on your 12v battery. It WILL charge it and you need a dump load or clipper device to prevent over charging, but it will work. Only problem, is that if you expect to see any quantifiable energy out of the turbine, you need to allow the rotor to operate at somewhat an efficient speed vs. voltage point. If you clamp it to a 12v battery, the rotor will stall (but it will still work to an extent). You could add quite a bit of feed line resistance to pick up a bit of rotor speed to increase your energy capture, but not without adding a bit more of feed line loss.

If you have not heavily invested in all the balance-of-system components yet (the ones that require certain set voltages) its probably less expensive to pick up a few more batteries for a 48v system than to start buying fancy DC-DC converters and adding more complexity. Just my opinion.

Have fun!!

RoyR
Have Fun!!!  RoyR KB2UHF

johnnym

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Re: 12 volt slave setup
« Reply #7 on: February 11, 2017, 08:15:26 AM »
Electronbaby, Do you think this would be able to power 2 led 7 or 10 watt light bulbs? So the maximum wattage would be 20 watts. This will be connected to a 12v battery. The inverter can handle 410 watts. So with the loss it seems that with what I am trying to use it for should work.

We had 26mph winds yesterday according to the closest weather station but that is around 20 miles away. It was way higher in my area. Probably at least 40mph if not higher.

tanner0441

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Re: 12 volt slave setup
« Reply #8 on: February 11, 2017, 08:48:13 AM »
Hi

Your comments on wind speed.  From experience don't assume anything.

I used to live in a place where the mean wind speed was assumed to be around 20MPH (by me). when I measured it I found it considerably lower. A 40MPH wind could give you difficulty standing still. The place I am at now gets some very strong winds but when I put a turbine up it spent more time pirouetting like a ballerina with the turbulence.

A cheap and cheerful anemometer from EBay isn't expensive and takes all the guesswork out of the equation.

Brian

johnnym

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Re: 12 volt slave setup
« Reply #9 on: February 11, 2017, 10:33:16 AM »
Yes, our back patio porch swing got knocked over. The cushions for the swing blew away.