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Monday, August 31, 2009

Homemade Deep Well Hand Pump

I found this site today and the "well" page is pretty interesting.
http://www.fdungan.com/well.htm

It talks about driving your own 80 foot well with a wooden hammer or a post pounder. And it explains the different type of wells and how to dig them. But I found this homemade hand pump the most interesting.

It is made of some hose adapters and a brass ball. It acts as a check valve. This goes down in the well and is attached to some stiff UV resistant irrigation hose. When you pull it up and down it starts pumping water. It may take a lot of effort the first time you set this up but after that it is much quicker because it doesn't lose its prime. I estimate about 50 strokes per gallon.
Also, even if you are going to use an electrical pump, this manual pump still comes in handy for when you first dig the well. It allows you to clear out the sand and silt very quickly.

This type of pump will work for years and doesn't require maintenance. Pretty impressive for just a few bucks at the hardware store. Looks like it would be great for emergencies or for off grid water pumping.

Richard

Wednesday, August 26, 2009

Liar Liar Pants on Fire

Today I was browsing ebay looking at wind turbine stuff. I came across this link here. Here is an excerpt:

Wind Turbine 1000 watt. Complete system minus inverter and battery

This is the Best of the Best. Made in Michigan. Made in the U.S.A.

This high out put 1000 watt Wind Turbine is the best out there to start with;

The frame is made of 6061 aluminum aprox 52 inches long strong yet light. bolted together with stainless steel washers nuts and bolts. This unique designed lets you install the wires down the center of the tube so the wires wont get tangled up.This is truly a work of art.

Dont buy a frame thats made out of cheap steel from china then welded by a amatuer and painted over, the frame will rust crack paint will chip off and will look terrible in weeks

This heavy duty motor/generator can produce a 1000 watts as a wind generator. The wind generator is rated for 130 volts dc 8 amps and reversible (creates electricity spinning in either directions they have thick magnets and brushes inside the housing. The outside housing is painted with white epoxy paint.The motor hits about 12 volts at 12 mph start up speed is about 3-4 mph. This is a awsome motor.

Dont waist your money with one of those 200 watt systems

These blades our the best out there. You get 3 turbo torque aircraft grade aluminum. The blades are about 5 inches wide at their widest and 24 inches in length (diameter of swept area is aprox 52 inches) with hub. These are cnc machined with a dimensional tolerance of .005 inches. They are perfectly balanced and spin very smooth.they are light strong and will not rust built to last , low wind start up about 3-4 mph. Our blades can with stand 70 mph.our blades our field tested and under go hundreds of hours of prototyping.

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This upsets me. Some people read this and don't see the problems.

1) It says a 1,000 watts - and we know that 8 amps multiplied by 130 volts is 1,040 watts. But, in real life we are charging a battery. In this case a 12 volt battery. If the battery is maxed at 15 volts and you put out 8 amps then that is only 120 watts. But in cold strong wind you can get up to 3 times the current rating, making this a 360 watt wind turbine system at best.

2) It only produces 12 volts at about 12 mph wind. But a battery is usually 12.7 volts or more and the voltage drop across the diode is 0.7 volts. That means that you need 13.4 volts or more to start charging. So, with a 4.3 foot diameter blade (52 inches) that means on a breezy day when the average wind speed is about 17 mph, you would only average about 50 watts of power.

3)This is one of those cheap treadmill motor that has very poor bearings. It will break under high winds and prolonged use. These motors don't produce any usable power until you get to high rpms and that means it is a poor choice for wind turbine use.

4) If the blades are 30% efficient and the motor is 50% efficient, then overall the system is 15% efficient. When I put that in my motor analyzer, I get the following:

So, the part of the description that says don't waste your time with a 200 watt system is obviously misleading. This system is basically a 200 watt system in a "real world" situation.

5) Notice that I used a TSR of 5 and RPM of 4500. But, that is very generous of me since most treadmill motors have a 5,000 or more RPM rating. Also, TSR of 5 implies that the blades have lift. A curved surface alone will not make much lift. You need a curved leading edge and a sharp trailing edge. I'm guessing that this blade would have about a 3 to 5 TSR rating.

6) I like aluminum, but remember, even the best aluminum will get micro fractures at stress points and they build up over time. But the thick pvc pipe painted with titanium dioxide paint will last for years.

7) Just because the blades can handle 70 mph winds doesn't mean that the little bearings in that cheap motor can handle that for any length of time.

So, this is about a 200 to 300 watt wind turbine that needs a very breezy location to make any usable power. And the motor bearings will break in about 6 months to a year. There is a way to use these motors and make them last...but this aint it.

Richard

Friday, August 21, 2009

Some more Fog Catchers

I like the concept for collecting water from fog. There are a lot of places that could use this and it requires no electricity.



I have an idea that you could make electricity with this as well, using the "electret effect". But I'll do some more research into that and some testing before I write about that.

Have a good weekend,
Richard

Wednesday, August 19, 2009

Temperature Coefficient for Electrical Resistivity

I remember telling someone in a forum about using stainless steel bolts as a shunt for use as a cheap current measurement. Someone else said that shunts are made with exotic (aka expensive) materials with very low thermal coefficients of resistance. I found this chart not too long ago and thought I would post it.

As you can see, stainless steel has a negligible coefficient. So, I feel vindicated. Stainless steel is exotic by the way. It is just mass produced and used for construction, thus making it pretty cheap.

Richard

Tuesday, August 18, 2009

Video of Motor analyzer update

Here is the video showing it in operation. Remember, if you purchased this in the past then this is a free upgrade.