turbine charging.

[turby44]

hi folks,

     i have a very good 2kw turbine which works a dream,its 120 volt with a battery bank of 2x10piecex12volt105ah ,i also have a 72volt forklift truck,i would like to charge the forklift battery from the turbine controller which is the recent new digital job and 120 volt,i have to step down the charge from 120 volt to 72 volt,has anyone got a good idea as to how to go about doing this,?or can anyone put me in touch with such a transformer even if it is just a trickle charger.

         holding breath,,

                turby.

[Electron Pump]

  W.O.W. Thats a lotta volts man! If your turbine is at 120v, got any idea how many amps? How steady is it at that voltage? Is that open volts? I think this one is over my head. Better let someone else field this one. W.O.W. 120v windmill!

[Dan the Handyman]

Hey Turby,

 You might want to try the guys over at allaboutcircuits.com for some help. It is not just a transformer you will need. You will also need a bridge rectifier, a controller, and a dump (or off switch). The ideal for transformers is primary vs. secondary number of turns: 120VAC - 12VAC = 10 turns primary to 1 turn on the secondary. Of course there are many other factors involved. 10 turns is basically a short, and probably will fry your generator. It is only an example: the ratio of turns, and the gauge of the wire will determine the output (impedance).

 Is your unit commercial? Then check the warranty.

 Hope this helps.

 Dan the Handyman

[turby44]

hi electron pump,

             this turbine is rated 2kw with a peak of 2.5kw and the controller runs the 120vdc to the the inverter which is 2kw sine and fairly common.we use halogen fires during very windy weather this eases the pressure on the controller,stops it getting warm but still allows the abs like braking to function in a force 8.

   i have this notion that i could charge the 72volt forklift and every once in a while do some work around the yard with it.i dont have to be a rocket scientist to figure out that the normal charger for this forklift battery would cook my precious 2kw sine inverter but somehow there must be a way that the 120volts dc from the controller can be channelled down to 72volt dc and charge my forklift.

  regards,

          turby

   

[turby44]

hi dan,

       thanks for the info,i will contact these people and hopefully they will come up with a solution,

           regards,

             turby.

[Dan the Handyman]

Hey Turby,

 You are welcome. Please let us know what you find out. If you see a guy there Sgt. Wookie don't be put off by his name. He's super smart. Just tell them to keep it simple. They'll have you building the master computer, when you need an egg timer;-)

 Dan the Handyman

[oztules]

If you want to trickle charge, and wish to stay low tech, a capacitor coupling in parallel with your normal system will bleed off a few amps without unduly upsetting the load matching. You can pick the size to suit the trickle charge / loading your after. Even this will still require it's own diversion or cut off controller, so when the 72v bank is full, it just leaves the normal 120v system in place.

Very simple, and very do-able.

Gordon over here: http://www.thebackshed.com/Windmill/FORUM1/forum_posts.asp?TID=1138&PN=2&TPN=1 will give you the idea. He uses parallel cap system to drive the 24v battery system and the 48v grid tie inverter concurrently..... and a cap booster as well.,... beware the article is 30 odd pages long.

..........oztules

[turby44]

hi oztules,

         thank you for the help,i will look for suitable capacitors and hopefully get the voltage correct.the present batterybank is made up of 2 rows of 10 x 12 volt 105ah powersafe batteries one atop the other which perform well.i had considered moving across the rows and tapping into the 6th and coming out with 72volts to the forklift battery.leaving the controller still charging 120 to the main battery bank,it sounds too simple and i guess i could be left with a mess,of which damaged controller and batteries might be the least.the capacitors seem the best route.

    thanks again

               turby

[turby44]

and still i search for the best answer,i look through "electrics for dummies" and "practical electronics" and i gather that i will need a capacitor,resistor amd diode,does anyone know the ratings on these little geezers and how to set them up.

      the general idea is,,to bring the charge coming from my 120volt turbine controller down to 72volt to charge my forklift truck batteries.i would be much pleased and jolly happy to be able to do this.

       still loking,

           turby

[oztules]

http://www.fieldlines.com/story/2006/9/29/231514/003

http://www.fieldlines.com/story/2008/5/20/2347/87104

These refer to using caps to charge EV battery banks, forklift banks etc. You only need access your 120vac (before the main diode bridge from your mill), 24uf/amp ac capacitors, rectifier diodes and some thing to turn it off when charged. (modified Ghurd controller perhaps)

It doesn't get much simpler than this.

...........oztules