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Re: Dump load / LVD circuit

PostPosted: Wed Jun 30, 2010 8:16 am
by windgat
Hi Rod. You could just connect it up, and probably what will happen is the turbine will run at half speed, making it very inefficient, but it would still charge the battery. (The battery would clamp the voltage to around 12V-14V as long as it is not fully charged.)

An alternative is a DC-DC converter, which takes in 24V and puts out 13.6V or so. They use this in trucks (which run on 24V) to run things like 12V music systems.

Re: Dump load / LVD circuit

PostPosted: Thu Jul 01, 2010 6:33 pm
by rod
Hi Windgat,

Thanx for the info i will try it over the weekend.
I got a dump load unit from the USA but they sent me a 12 volt unit.
My system is a 24 volt and they told me it would damage the relay if i connect it.
That is why i need the dump unit from you as soon as possable.
I need to get this bird flying.

Thank you ,

Rod.

E mail or ring me and will do the transfer.

Re: Dump load / LVD circuit

PostPosted: Mon Jul 05, 2010 2:05 pm
by windgat
Cool. I haven't got around to doing a costing yet, but I think R350 would cover it, incl postage. But I haven't yet sent one off to someone, so to be the guinea pig I'll make it R250 for you. First please make sure you have read the web page, so that you understand what the circuit does, and what you need to add to it to make a functioning dump load.

Re: Dump load / LVD circuit

PostPosted: Wed Jul 07, 2010 9:21 pm
by rod
Hi Windgat
Connected the 12 volt dump load unit from usa to the 24 volt turbine as you sugested and it works like a dream.
Thank you for the info on your 24 volt dump unit but how do i get the funds to you let me know your shops phone number and i can get the info and transfer.

Please send me a drawing on what to connect where,i have read your site over and over but some entries i do not grasp.

Thank you,

Rod. :yay:

Re: Dump load / LVD circuit

PostPosted: Fri Aug 06, 2010 7:03 am
by naveenck
Hello Windgat,

I am building a battery charging circuit that uses an input similar to wind - unpredictable and having a wide window of voltages and I need help to build a charge controller for the same. I find your circuit is a good starting point.

However, I need to charge 12V Lead Acid batteries and hence want to know what modifications need to be done to make charge controller feed 14.4V to charge the 12V lead acid battery.

Kindly send in your thoughts.

Thanks in advance,
Naveen

Re: Dump load / LVD circuit

PostPosted: Sun Aug 08, 2010 3:33 pm
by windgat
That should be simple. Just adjust the voltage divider to be approximately 1 to 5 instead of 1 to 10: see R1 and R2 on the page:
http://windpower.org.za/loadcontrol/loadcontrol.html
An alternative would be to adjust R3 and R4. Once you find values that work, please share them here.