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KiwiJohn
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Joined: 01/12/2005
Location: New Zealand
Posts: 691

Posted: 06:51am 12 Oct 2007

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We have a lot of very knowledgable people posting on this site but maybe there is still room for this simple idea!

Here is a simple circuit that will double your voltage (or halve your current) with just a single relay change over.

The AC from the alternator comes in from the left and with the relay contact to the left (as shown in the diagram) we have 'normal' full wave rectification for charging our battery via the two connection on the right.

Switch the relay contact to the right however and the circuit converts to half wave, voltage doubling rectification. One half cycle charges one of the capacitors and the other half cycle charges the other. The total voltage of the two capacitors is available to charge our battery.

I suggest the way to use this would be to configure our F&P for a low voltage by putting more coils in parallel. This will decrease series resistance and increase the available current but the voltage at low generator RPM may be too low to charge the battery, that is when to use voltage doubling mode.

When the wind picks up the circuit is switched to 'normal' mode to avoid excessive voltage.

I think the circuit could be made fully automatic by wiring the relay coil across the AC input with necessary series resistance to cause the relay to switch at the desired voltage level.

I guess we could also use the voltage doubling mode to increase the voltage and reduce transmission losses when the alternator must be a long way from the battery.
Edited by KiwiJohn 2007-10-13

KiwiJohn
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Joined: 01/12/2005
Location: New Zealand
Posts: 691

Posted: 08:16pm 12 Oct 2007

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Oh well!

herbnz

Senior Member

Joined: 18/02/2007
Location: New Zealand
Posts: 258

Posted: 09:11pm 12 Oct 2007

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Hi John

Yea this is as you say a well known cct used extensively in pc supplies to change 230 v to 110 v input.
It could be used in FP need one per phase parallel outputs a simple switch/relay will double volts for low volts
another simple technic use three indepentant for low volts then short one AC side bridges to change star only needs two normally open contacts.
Good to keep feeding in ideas even if no immedite response brain storming stirs our brains along.
Even ideas that are not right are good I once worked for FP one director there would always throw in studid ideas to get team going ie elements in heaters to costly lets leave them out sell as separate item.
Not that your idea's wrong

Herb

Highlander

Senior Member

Joined: 03/10/2006
Location: Australia
Posts: 266

Posted: 09:25pm 12 Oct 2007

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G'day John, that's a nice trick!

This looks good too, however a little more complex.
here

Dunno how you would scale it up though.

Edited by Highlander 2007-10-14

Central Victorian highlands

adelaide
Regular Member

Joined: 24/03/2006
Location: Australia
Posts: 46

Posted: 10:01pm 12 Oct 2007

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speeking of simpl reliable hears 2 idear i segested long time ago .
have say a 80(or any the same )p for 2/3 of stater and a 80 s/p for 1/3 that ratio could be moved depending on results but key is 2 x 3 phase rectfiers / result is 80 sp makes unifishent power at lo wind and hi wind makes unifishent power + 80 p makes no power at lo wind but makes efishent power at hi wind .
also can better fixed on outher side problem with fast big props /(hub extenshons esenshal(big cord at root to 1/2 way as per blade calqulater recomends (out cuved plastic or tin glue screw/g force /i used for 5 years )))
for starting hi tsr prop and you cant beat mached bigger props for av power cos you may be trying to make some power out to little swept aria

help to make progres or radio and vitamin b

Warpspeed
Guru

Joined: 09/08/2007
Location: Australia
Posts: 4406

Posted: 10:41pm 12 Oct 2007

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herbnz said Hi John

Good to keep feeding in ideas even if no immedite response brain storming stirs our brains along.
Even ideas that are not right are good I once worked for FP one director there would always throw in studid ideas to get team going.
Herb

Very true !!

This is the concept of the "think tank". Someone comes up with some crazy idea that may not be entirely practical. But it starts other people thinking in directions that may not have otherwise occurred to them.

Keep the ideas coming guys, it is all good.

Cheers, �Tony.

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