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Frank Newbie Joined: 13/10/2010 Location: Posts: 5
Posted: 05:09am 24 Oct 2010
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I have been following this forum for a while as I have built an undershot water-wheel which is driving a F&P 80 in star. 7 groupings of 6 coils. The water-wheel is geared R1:48. The water-wheel does 1 revolution every 6 seconds = 480rpm.
Unfortunately my cable run is 160 meters with 16mm squared cable. hence some losses.
Even so open circuit, 50V. 1R:4 seconds. Connected to batteries, 7 Amps and Volts are still able to switch my tristar controller to equalization 30V and hold PWN absorbtion 29.2 Volts.
I have tried the 36 pole stator in Deltor 7 amps at about the same RPMs as 80 F&P, as well as the 7 phase 2X3 coils. Much better volts, 110V open circuit. But connected to battery the load on the wheel reduced RPM to 350 RPM 7 Amps.
The load eventually broke one of the drive chains.
I have tried to give the amps and volts, on the 80, 36, and 7 phase at the same RPMs. Due to rain of course water flow varies. I've had as little as 4 amps and as much as 11 amps.
The creek flows all the year round and I only use half of the flow for the wheel.
Question: Will caps help to increase power in my situation? If so on my 80 in star, correct me if I'm wrong, 2 DC electronic caps back to back 400 VDC 330 UF on each phase with 100 K lead resistors. Or am I using the wrong generator altogether?
Don't get me wrong, I am very happy with what I've built from scratch but I think we all try for a little bit more power.
Frank
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 09:20am 24 Oct 2010
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Hi Frank,
Some photos would be nice.
Caps help prior to cutin when the rpm is lower than needed to get enough voltage to reach the battery voltage.
I dont think in your case caps will help as you are already way over cutin voltage for the battery.
Gordons the expert on caps and im sure he will comment soon on this.
Pete.Sometimes it just works
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 11:14am 24 Oct 2010
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Water boys tend to run their f&p's much higher RPM's than the wind turbine boys typically,perhaps try running more rpm's????????Luck favours the well prepared
GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127
Posted: 01:59pm 24 Oct 2010
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Hi Frank,
caps are all about loading and matching, and allowing power to be harnessed in the power region below and close to cutin. Caps work well with a windmill, but would be not much advantage on a controlled power source like a water wheel. A well matched water wheel will likely have a higher efficiency without caps.
I have no experience with hydro systems, or even lathe testing. The unique nature of the wind and a windmill allows the caps to do their thing.
Gordon.
become more energy aware
Frank Newbie Joined: 13/10/2010 Location: Posts: 5
Posted: 12:04am 25 Oct 2010
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Thanks Pete, Karl and Gordon for your replies. Maybe I'll have to try more RPM's or just be happy with what I'm already getting.
I shall be putting a new post on called 'Franks's undershot waterwheel' along with some photos for those interested.