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AleemAhmedAnsar
Newbie

Joined: 07/06/2009
Location: Pakistan
Posts: 1

Posted: 01:21am 08 Jun 2009

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Dear Friends,
I am Aleem Ahmed Ansar a new member to your club,and posting these few lines expecting that your replies will be beneficial .
I belong to Pakistan where there is an acute shortage of electricity, leave alone the rural areas even in the larger cities we have a load shedding of electricity for almost 12 hours in intervals.I plan to build small, cheap domestic units of windmill capable enough to charge a 12 volts battery.Obviously wind is no problem around here.The result I need is to glow one lamp of 60 to 100 watts and a fan of 55 to 75 watts. This will be sufficiant for the poor people .This is a noble cause and I sincerely hope that all of you reading this shall help me in what ever way possible.
I have been able to successfully complete the mechanical part of the wind mill though rather crude but very cheap.It is erected approximately 40 feet above ground and the fan turns approximately at 300 to 400 revolutions (not checked by a tachometer)in average wind what we have here.
I was told that I should put up a car dynamo 12 volts and 50 kw to charge a 12 volt battery because it will prevent the battery from overcharging,but I made the wrong connections and spoiled the dynamo, a second dynamo was tried by the help of an auto electrician but he said that this will not work as the load is too much.You must have realised by now that my electrical side is extremely poor, so please help me.

Questions:
1.Are the rpm of the blades low?
2.What is the best DC motor that can be used, describe fully?
3.Can we increase the revs by using pulleys ,or will this arrangement increase the weight further,or the 3 blades 2ft each require some alteration.
4.Do we require any electronic controls for such a small arrangement.
5.Is it possible to connect the wires to a "UPS"(uninterrupted power supply unit)to achive a 220V AC.If yes where should these connections be made.
6.Where can I use a meter to see how much voltage the wind mill is capable of in different winds.

Please consider that my english is very simple so dont use very dufficult words in your reply.Any advice you consider might help is most welcome.I am awaiting your reply anxiously.
Thanks.
GOD bless you all.
Aleem Ahmed Ansar.
Karachi(Pakistan).

I am trying to build a domestic windmill generator for needy people of my country at a very small price.

KiwiJohn
Guru

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

Posted: 03:25am 08 Jun 2009

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Salaam, welcome to this forum Aleem, I am sure all the answers to your questions can be found right here as we have some very experienced windmill builders regularly posting here..

Regarding your questions
Questions:
1.Are the rpm of the blades low?
This is hard to answer without knowing how you designed your blades but if it is turning at 3-400RPM that is certainly evidence enough that you are on the right track!

2.What is the best DC motor that can be used, describe fully?

The best DC motor is a permanent magnet motor designed for at least 30 volts. When operating as a generator your voltage output will be a little less than when operating as a motor for the same RPM. If you have a DC motor to test the first test is to connect all the wires together and see if it is hard to turn by hand, if it is hard to turn with the wires connected together but easy to turn with the wires connected to nothing you have potentially a suitable motor.

3.Can we increase the revs by using pulleys ,or will this arrangement increase the weight further,or the 3 blades 2ft each require some alteration.

Yes, you could use pulleys but few people choose to do this, as you say it increases the weight but it also wastes precious energy and makes your machine require more maintenance.

4.Do we require any electronic controls for such a small arrangement.

Almost none for a small battery system, the load of the battery will prevent the voltage from going too high except if you have a long period of high winds and no load on the battery. The minimum electronics required is a diode to prevent the battery discharging through the generator when the wind dies.

5.Is it possible to connect the wires to a "UPS"(uninterrupted power supply unit)to achive a 220V AC.If yes where should these connections be made.

Hmmmmm.... I think this might be possible just by connecting your generator output wired to the UPS battery but I am not confident in saying this.

6.Where can I use a meter to see how much voltage the wind mill is capable of in different winds.

You need two meters, one to show amperage (current) and one to show battery voltage, with those two and with advice from here you will be able to measure your generator output.

There are many people on this site with more knowledge and experience than me and I am sure they will be along soon to assist in this discussion

Best wishes for your project which I am sure is very worthwhile. I have visited Pakistan including Karachi a few times and always enjoyed my time there.

Best regards
John
Wellington
New ZealandEdited by KiwiJohn 2009-06-09

Robb
Senior Member

Joined: 01/08/2007
Location: Australia
Posts: 221

Posted: 01:15pm 08 Jun 2009

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Can you list what type of motors are available to you?

KiwiJohn
Guru

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

Posted: 02:01am 09 Jun 2009

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...deleted by me!

Edited by KiwiJohn 2009-06-10

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