The dynamo gives out 6-140volts I want to charge a 12v battery bank using a water wheel. I'm used to solar power, the controllers only go up to 50v.

 

Is the dynamo connected to the water wheel in an operating system ?
Is the 6- 140 V DC ?
What is power rating of dynamo ?
What is Ahr. rating of the battery bank ?
Have you ever tried varying the field current to see the effect on output V ?
The control might be = or similar to an older 12 automotive alternator regulator.
I know nothing about water powered dynamos.

 

Put a few light bulbs in parallel on the genny. Several 60W incandescent bulbs would do nicely. Then what is the highest voltage you get?
I suspect it needs a load bank for dumping excess power when charging finished or other loads go off.

 

How many rpm do you need to get 140V from the dynamo? What size water wheel? What water flow rate?

 

Is the dynamo connected to the water wheel in an operating system ?
Is the 6- 140 V DC ?
What is power rating of dynamo ?
What is Ahr. rating of the battery bank ?
Have you ever tried varying the field current to see the effect on output V ?
The control might be = or similar to an older 12 automotive alternator regulator.
I know nothing about water powered dynamos.

The dynamo will be connected directly to the water wheel in an operating system.

The power rating of the dynamo is 1000watts see link below

http://www.ebay.co.uk/itm/112360400708?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

The battery bank will be 240Aph
I have not tried anything yet still waiting delivery.

The company selling suggest
a normal charge regulator from 30A
but these seem to have a top limit of 50v
I'm thinking that I probably will not reach this voltage

 

How many rpm do you need to get 140V from the dynamo? What size water wheel? What water flow rate?

The water wheel will be 2"dia
Below is a link to the dynamo which will be connected directly to the water wheel.

http://www.ebay.co.uk/itm/112360400708?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I do not know the water flow all I can say is its moderate.

 

The water wheel will be two feet diameter
Below is a link to the dynamo which will be connected directly to the water wheel.

http://www.ebay.co.uk/itm/112360400708?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I do not know the water flow all I can say is its moderate.

 

I do not believe that your 2 inch diameter water wheel will turn this motor with it's 240:1 step up (When used as a generator.) gearbox. The information in the advert contradicts itself. The claim that the gearbox steps up POWER is wrong. A gearbox will always output slightly less power than the input power.

Les.

 

I do not believe that your 2 inch diameter water wheel will turn this motor with it's 240:1 step up (When used as a generator.) gearbox.

Even if the wheel is 2 feet diameter I share your doubts, Les. Maybe if the wheel is positiond at the foot of Niagara Falls it would work .

 

At 1600 gallons per minute with a 10 foot head there is 4.0 water horsepower.

It can work with sufficient flow rates, but 2 inches dia. Is a LONG way from 1600 GPM.

 

From "Producing Your Own Power", Net horsepower available at turbine shaft = ( cubic ft./ sec. X gross head in ft.) / 8.8 . You would need about 2 HP or better for 1 kW DC output.
A 2 ft. dia. wheel seems fine depending on type & head.

 

From "Producing Your Own Power", Net horsepower available at turbine shaft = ( cubic ft./ sec. X gross head in ft.) / 8.8 . You would need about 2 HP or better for 1 kW DC output.
A 2 ft. dia. wheel seems fine depending on type & head.

Thankyou for all your replies
it is an under driven water wheel and I am building the prototype. I will post my results.

 

it is an under driven water wheel

What head of water is available?

 

What head of water is available?

Hi yes it is a under driven wheel floating on a catamaran.

 

So, it's a bit like a paddle-steamer operating back-to-front .
What is the maximum speed of the catamaran?
What will the dimensions of the paddles themselves be?

 

Under cut water wheels are only 30-40 percent efficient. So whatever power calculation used for available water energy will be reduced by the efficiency factor of the water wheel type you choose. Spiral vanes on a flat surface wheel with center intake and peripheral outflow can be over 60 percent efficient.

 

At 15 mph, I get 209 rpm before efficiency. At 40 % =~ 500 W, , something is wrong ?

 

At 209 wheel rpm, with 100:1 gearing (the gearing spec is confusing and says "Ratio 240:180:120/1") the generator shaft would be spinning at an unrealistic and over-spec 20,900 rpm! Rated rpm is 6000.

 

Sounds like it might work, now to original question -how to control output. I'm guessing that wheel can be raised & lowered, if so, gross control might be by depth of immersion, fine control with a buck converter, or charge controller. Output V can be monitored & cause disconnect or raise signal if V approaches 50 V?
Might look at -www. greenenergyhydrocat.

 

Found a graph of stream velocity vs power. Looks possible.