Author Topic: would this circuit work?? (Read 3117 times)

(unknown) · « **on:** February 06, 2009, 02:25:29 PM »

Hi, would this circuit work? Input 3 small turbines into bridge rectifiers, outputs to regulators with caps and connect the caps in series to increase the voltage at the output? I do not have a lot of experience with power circuits and any feedback would be greatly appreciated.

TomW · « **Reply #1 on:** February 06, 2009, 07:44:29 AM »

Odin;

I think it is a gross overthinking of the plumbing. Problem is, you don't explain "why" you want all this complexity or why you want a regulated 15 volts?

If it is for battery charging you are way over the top.

Maybe a bit more info on what you are trying to accomplish will yield an elegant solution from our brain trust of electronic gurus that hang out here?

Bottom line, as drawn, I do not think it will work. Seems those regulators all sharing a common ground that each output is referenced to and will not really be in series? It may make a great light show and smoke cloud but not sure.

As usual, I could be wrong on the "will it work" part.

Tom

RogerAS · « **Reply #2 on:** February 06, 2009, 07:48:14 AM »

Until a fuse is blown and the turbines run free, yes this will work, to an extent. When one or more of the fuses or regulators fail the turbines will go into runaway. Not a good thing.

If you are looking at LM7805 regulators you will be limited to 1 AMP at the final output as pushing them past this point usually releases the magic smoke.

Instead of your arrangement why not series the output from the rectifiers, place a much higher voltage rated cap across the final output of the rectifiers, and an in line blocking diode after the cap? That final diode will stop back drain of keeping the caps charged when the wind dies.

My base question is what the effort of this circuit is to be applied? Charging batteries will eliminate the need for regulation as the batteries will clamp the output until fully charged, and at the point a dump load must be employed to protect these batteries.

More detailed information as to the purpose of this device will allow us a more informed response.

Opera House · « **Reply #3 on:** February 06, 2009, 08:30:19 AM »

Absolutely has no chance of working.

You can't have three 5V regulators all referenced to the same common and somehow add them up.

Rectify each winding separately and add them up without a common ground.

Flux · « **Reply #4 on:** February 06, 2009, 08:31:28 AM »

No it's just about crazy.

you must have some very tiny thing in mind to consider feeding standard integrated regulators.

Turbines in series have been mentioned before but I see little hope of much success as they will not all see the same wind at once.

Series regulators don't work with wind turbines unless they have pitch control and even then the idea is not a useful one.

Trying to produce a regulated output from wind without batteries is not practical either.

Finally it would be foolish to run three machines in series when one correctly designed one would do the job. If you have three then get them to work properly and run in parallel.

If these are really tiny machines such as stepper motors and the blades are incredibly inefficient and the things never goes over 40v in a gale then it might sort of work if you sort out the regulator grounds but the power out would be negligible and any load in excess of that produced by the turbine with least wind would drop the regulators out and volts would drop.

Flux

(unknown) · « **Reply #5 on:** February 06, 2009, 08:35:25 AM »

Hi, I live in a low wind area and the small alternator I built produces 6 volts at about 250 RPMs which works will the VAWT I fabricated. I am trying to stay away for larger units and tall towers; dealing with the local government and zoning is to much of headache; so I am planning to construct 3 small turbines that are roof mounted and connect them to charge a battery bank. The turbines are low cost and easy to fabricate but I need a circuit that will connect the 3 to get charging voltage that I can connect to dump load charging circuit for charging the battery bank.

Flux · « **Reply #6 on:** February 06, 2009, 08:48:48 AM »

It would have made more sense to wind the alternators to suit the job. If you need 3 in series then using 3 times the turns would have got you there.

If you must run them in series then you can use the bridges in series and if it is single phase a large capacitor across each bridge will help a bit. No need for regulators ( if you need regulators you need a shunt one across the battery feeding a dump load.

Probably if it's a Vawt you may not exceed the rating of series regulators and you may never exceed their voltage rating but it is still crazy to use series regulators.

The individual bridges need connecting in series, you can't use a common ground as you showed.

You stand a better chance of success if the alternators are powered from one turbine so they all have similar output at any time. If you use 3 turbines with alternators in series then the one seeing the least wind will decide your power unless the other 2 can manage battery volts alone.

Flux

(unknown) · « **Reply #7 on:** February 06, 2009, 08:52:48 AM »

Thanks Roger, your idea seems worth trying, thanks for the input and have a good one.

(unknown) · « **Reply #8 on:** February 06, 2009, 08:55:02 AM »

Hi, like a Jerry configuration?

(unknown) · « **Reply #9 on:** February 06, 2009, 09:02:08 AM »

Thanks to all for putting on the right track. I will post the results in the diary section when the project is complete. Thanks again.

electronbaby · « **Reply #10 on:** February 06, 2009, 09:43:15 AM »

Your keywords are: VAWT, and ROOF MOUNT. I think your moving in the wrong direction personally. If you have 250RPM, then it would make more sense to wind one alternator to accomplish the task. This will be the most efficient for what you are trying to achieve and you wouldn't have to mess with all the unnecessary components that will lead to a failure eventually. But, this has already been said.

Or perhaps you reasoning is to spread the annoying vibrations out over your whole roof instead of one location?

tecker · « **Reply #11 on:** February 06, 2009, 10:01:44 AM »

The real problem is the regulators won't series load like that and the caps won't pass the dc for certain .The way to get this to work is to charge 5 or 6 volt batteries from each turbine and series that . It works well and you don't have to worry about anything but the bridge . Make your bridge larger than what the output is and use long wire that matches the max load you want to take of from each turbine if the wire gets warm upsize until it runs cool.

Norm · « **Reply #12 on:** February 06, 2009, 10:29:57 AM »

In good weather (above freezing) why not just have

small pumps to pump to a water tower when

the water level reaches overflow....it self siphons

to a lower reservoir thru a water turbine and

generator to charge a battery if the battery is

fully charged a by-pass valve opens to the lower

reervoir.

Should be no worry about run away or stall??

tecker · « **Reply #13 on:** February 06, 2009, 10:46:50 AM »

C size Nicads will load to fairly high amperage and charge fast (and are cheap ) when they go bad they still plump up with the wind and act like Caps . You can regulate of the nicads or just use them as is if they won't drop to very low volts for long periods .

ETech · « **Reply #14 on:** February 06, 2009, 12:38:20 PM »

Since the circuit is DC.

Each of the capacitors will act like an open circuit to DC, NO CURRECT FLOW.
As others have said each of the 5 volt regulators are referenced to the same point (ground).
it would be easier to connect all of the rectified DC outputs in parallel and then regulate the combined outputs.
Three terminal regulators are available in 3.3v, 5v, 12v, 15V, and programmable outputs.

For charging batteries you may want to skip the regulator and use a dump controller.

Etech

boB · « **Reply #15 on:** February 06, 2009, 01:51:22 PM »

>>The real problem is the regulators won't series load like that and the caps won't pass the dc for certain

and

>> Each of the capacitors will act like an open circuit to DC, NO CURRECT FLOW

That is what I thought also.

AND, NOW you will have something that is normally only common and unwanted in the solar industry... Partial shading for wind turbines ! Now, THAT would be hard to track !

boB

tanner0441 · « **Reply #16 on:** February 06, 2009, 02:43:48 PM »

Hi

Looking at the circuit I can't see where you get the negative rail from, it does not connect anywhere apart from the capacitor on the first regulator. If it should show going to ground then all the regulators on your drawing share a common ground.

Brian

ghurd · « **Reply #17 on:** February 06, 2009, 02:44:40 PM »

The first thing I thought was even with the caps and grounds sorted out,

it leaves 3 windmills running at xA and 7V into the 7805 to get 70%, or about 2 windmills worth of power out of 3 windmills.

G-

TomW · « **Reply #18 on:** February 06, 2009, 03:20:13 PM »

Brian;

And I thought it was just me.

Tom

jimjjnn · « **Reply #19 on:** February 06, 2009, 06:31:52 PM »

I did a double check on it too. His output lines are labelled + and - But looks to me that they are both +

With no - output

(unknown) · « **Reply #20 on:** February 06, 2009, 08:33:54 PM »

Hi Roger, is this what you are recommending?

edy252 · « **Reply #21 on:** February 13, 2009, 10:50:33 AM »

hi...as others said...if the three 7805's have the same ground then their output has the same level (+5 volts) so u cant add them up...

second, i dont think that the regulator will like u trying to input current into its output pin....not sure...but i guess so

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Author Topic: would this circuit work?? (Read 3117 times)

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