Wind Generator Design - Page 2 - Electronic Circuits Projects Diagrams Free

jpanhalt · 5th November 2007, 11:49 AM

Quote:

Originally Posted by mynameisdan

For limiting the speed of the blades you can use a magnet brake.

It might be easier to make the blades with controllable pitch. So-called constant speed propellors for aircraft have such blades.

Second, do not underestimate the drag force against your windmill. A free-wheeling propellor has a drag force approximately the same as a flat plate of the same area as the propellor's arc. Thus, an eight foot propellor (arc area about 50 ft^2) feee-wheeling in a 30 knot wind would have a drag force of about 200 # (See: http://www.sailingusa.info/cal_wind_load.htm). You may want a brake on the prop to stop it from turning in a strong wind or a method of turning the windmill parallel to the prevailing wind. Feathering the blades also acts as a brake and further reduces drag compared to leaving the blades at their normal pitch. John

Hero999 · 5th November 2007, 05:47 PM

If you want to be clever you could design a turbine that eneables you to change the angle of the blades to limit the RPM.

**Krumlink** · 5th November 2007, 09:27 PM

I was thinking about a system of solenoids with magnetic brakes on the end that could slow it down with a push of a button

About the Batteries, what:
Voltage
Amperage

Should they be?

Also, what should I use to generate the voltage?

Super_voip · 6th November 2007, 09:04 AM

Quote:

Originally Posted by Krumlink

I think I like the Lead Acid batteries, and I could use the ones that my HS robotics team uses (they pull up to 100A). They are only 20$.

Or you could use AAA nicads they can supply a lot of current as well, really what you need is old telephone exchange batteries, they can supply a lot of current for a long time.

**Krumlink** · 6th November 2007, 08:34 PM

Quote:

Originally Posted by Super_voip

Or you could use AAA nicads they can supply a lot of current as well, really what you need is old telephone exchange batteries, they can supply a lot of current for a long time.

AAA NICADS may be too small for this scale. I am talking a few amps per hour, more than any NICAD for that matter could/would supply without overheating.

I like the Lead acid idea, and so does my Family.

I really need a generator now!

mneary · 6th November 2007, 11:04 PM

Your HS robotics battery is capable of providing high current for only a short time. Remember, the actual competition was 2 minutes, 10 seconds.

Leftyretro · 7th November 2007, 01:10 AM

Quote:

Originally Posted by Krumlink

AAA NICADS may be too small for this scale. I am talking a few amps per hour, more than any NICAD for that matter could/would supply without overheating.

I like the Lead acid idea, and so does my Family.

I really need a generator now!

There are special NICAD batteries that can supply tons of current, used in R/C models for high performance motors.

Just a standard NICAD 'D 'cell is rated at 4 amp/hrs I seem to recall.

Lefty

Hero999 · 7th November 2007, 06:58 PM

Quote:

Originally Posted by Krumlink

AAA NICADS may be too small for this scale. I am talking a few amps per hour, more than any NICAD for that matter could/would supply without overheating.

I like the Lead acid idea, and so does my Family.

I really need a generator now!

You want more than a few Ah which is what a typical AA NiMH cell can provide. You need a couple of hundered Ah at the very least.

**Nigel Goodwin** · 7th November 2007, 07:30 PM

Quote:

Originally Posted by Krumlink

I like the Lead acid idea, and so does my Family.

So does everybody else in the world - solar power, wind power - you use lead acid batteries, end of story really!.

**Krumlink** · 7th November 2007, 07:58 PM

Besides, the most amount of watts I would be using at any one time would probably be a max of about 200Watts.

I need a way to generate the voltage now

**Nigel Goodwin** · 7th November 2007, 08:14 PM

Quote:

Originally Posted by Krumlink

Besides, the most amount of watts I would be using at any one time would probably be a max of about 200Watts.

I need a way to generate the voltage now

As you suggested in the first place, a car alternator is an easy place to start.

**Krumlink** · 7th November 2007, 08:40 PM

How much would you think it would cost for a cheap one? I will have to check it out.

Hero999 · 7th November 2007, 09:37 PM

Nothing, go to a scrap yard.

Also note that car alternators aren't very efficient.

kchriste · 8th November 2007, 03:53 AM

A better solution than a car alternator would be to use a larger DC permanent magnet motor as a generator. If you want to use stuff from old cars, a radiator cooling fan motor may provide enough current as a generator. Years ago I made a windmill out of an old computer tape drive motor (Think large 1970s computer). I think the motor was designed to run from 24-48V so it put out 12V @ 10amps quite nicely at low RPMs.

Boncuk · 13th November 2007, 01:28 AM

Quote:

Hmmmmmm

What about a massive capacitor bank

Lead Acid Batteries?

Good point! WIMA has developed a capacitor not too big around with a capacity of 400F!
A 500F type is under development. One disadvantage they have: Charge is limited to 2.5V

The massive capacitor bank could be the garage filled with capacitors from bottom to top.

5th November 2007, 05:47 PM	(permalink)
Hero999 Experienced Member	If you want to be clever you could design a turbine that eneables you to change the angle of the blades to limit the RPM. __________________ What's so bad about Microsoft? Get Opera it's simply a superb browser.

5th November 2007, 09:27 PM	(permalink)
Krumlink Moderator Blog Entries: 1	I was thinking about a system of solenoids with magnetic brakes on the end that could slow it down with a push of a button About the Batteries, what: Voltage Amperage Should they be? Also, what should I use to generate the voltage? __________________ MechTronics

7th November 2007, 07:58 PM	(permalink)
Krumlink Moderator Blog Entries: 1	Besides, the most amount of watts I would be using at any one time would probably be a max of about 200Watts. I need a way to generate the voltage now __________________ MechTronics

7th November 2007, 08:40 PM	(permalink)
Krumlink Moderator Blog Entries: 1	How much would you think it would cost for a cheap one? I will have to check it out. __________________ MechTronics

7th November 2007, 09:37 PM	(permalink)
Hero999 Experienced Member	Nothing, go to a scrap yard. Also note that car alternators aren't very efficient. __________________ What's so bad about Microsoft? Get Opera it's simply a superb browser.

6th November 2007, 11:04 PM	(permalink)
mneary Experienced Member	Your HS robotics battery is capable of providing high current for only a short time. Remember, the actual competition was 2 minutes, 10 seconds.

8th November 2007, 03:53 AM	(permalink)
kchriste Experienced Member	A better solution than a car alternator would be to use a larger DC permanent magnet motor as a generator. If you want to use stuff from old cars, a radiator cooling fan motor may provide enough current as a generator. Years ago I made a windmill out of an old computer tape drive motor (Think large 1970s computer). I think the motor was designed to run from 24-48V so it put out 12V @ 10amps quite nicely at low RPMs. __________________ --- The days of the digital watch are numbered. ---

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