wind turbine speed?

i have herd that the minimum amount of wind required to power a (homemade) wind turbine is 10 m.p.h. is that true? and whats the maximum wind speed?

Topic by Sun Gear 8 years ago  |  last reply 8 years ago

Okay. now I have a grasp on my amp (or should I say watt) draw. I now need to figure how to make this wind turbine produce what I need. I've bought a small 200 VDC motor to build my first turbine from. This is just my 1st hobby wind generator to see if I can & how well. Probably the wrong one, but it's cheap enough and sure I'll use it for something in the future. 400 rpm seems really fast to generate 12v! So that's my first question... is it? To achieve this speed , in my area (Class 2) I can expect 4 hrs a day wind of only 3-7 mph (trying to stay very modest), so I assume I need multiple blades and gearing. 2nd question; How do I determine how many blades, of what size I should make to obtain a certain rpm in a particular wind speed? Not sure I asked that correctly, so please bear with me. Once I have this generator in hand I will be able to measure the torque needed to turn it. Then I assume I need to determine a blade size and count to meet this need. If that is still not enough, I assume I will then need to gear it and re-calculate the blades. Anyone out there have the math to figure this?

Topic by olddawg 10 years ago  |  last reply 10 years ago

Arduino wind speed detector - is it possible ???

Hello ... I would like to ask, if it is possible with ARDUINO to check the voltage from a small DC motor that is rotating by the wind and then to transform this voltage to numbers on the display ???I would like to make a WIND SPEED INDICATOR ... and that's why I decided to buy ARDUINO ... that's why I need your help/opinion if it is possible - if it is worth to buy it or it is not possible with ARDUINO. Looking forward to your answers. zholy

Question by zholy 9 years ago  |  last reply 5 years ago

British Land Speed Recod Was a Breeze, Thrashes US Record.

On the morning of March 26th, on the dry Lake Ivanpah, The Ecotricity Greenbird driven by British engineer, Richard Jenkins smashed the world land speed record for wind powered vehicles. The Greenbird clocked 126.1 mph (202.9 km/h) , eclipsing the old, American held, record of 116 mph , set by Bob Schumacher in the Iron Duck in March 1999 at the same location.The fully-composite craft (the only metal is in some of the bearings) used a solid wing to reach speeds up to five times that of the actual wind.The wing also provides unwanted lift, so it uses the same downthrust technology as F1 cars - at speed, the 600kg car presses down on the salt-flats with a force of almost 10,000N.Greenbird website.

Topic by Kiteman 10 years ago  |  last reply 10 years ago

what kind of experiment could be made to measure the speed of light (with a laser for exemple)?

Question by darkmind64 9 years ago  |  last reply 9 years ago

Hello, I need some help with counting the pulses  on digital pin with reed switch and arduino for speed meter and also calculation for the speed in km/h.

Question by Konstantin Dimitrov 3 years ago  |  last reply 3 years ago

Low-tech anemometer that records highest wind speed

I've been tooling for one of these for ages, or how to build one. It has to be low-tech: no electronics, no batteries if at all possible. I want to measure the highest-speed winds per day, not the actual windspeed at that particular moment. I live in a wind-tunnel and I'm curious to know just how strongly it blows My very vague idea was: windsock with a cord attached to the far end gauge with vertical slider, wind speeds marked, sliding part fitted with ratchet system so it can move up freely, but not down again cord on the end of the sock connects to the back of the slider: theory: the harder the wind blows, the higher the end of sock will be lifted, and the higher the slider will be pulled. Each day I'd be able to take the highest reading, then reset the slider back down for the next day I've got a cheap cup anemometer but I've no idea how to use its rotation speed to make measurements of course, marking the gauge accurately would be a bit tricky! Does anyone have any thoughts/tips/suggestions? Thanks! I've been looking vainly for "mechanical anemometers" but usually get the "take four paper cups" type, or the pukka ones at £££ or \$\$\$. it'd have to stay outside all the time, so a battery one wouldn't be much use

Question by HelenaTroy 6 months ago

can we use a kite for increasing speed of wind mills. by tying kite while it is going up to the back of wind turbine.?

i wish some one  passes the thread of kite once going round thru backside of wind turbine then if the kite flies higher the thread will move blades of wind turbine faster and we can get more electricity for very less effort .

Question by jignesh shah 9 years ago  |  last reply 9 years ago

How can I wirelessly access a wind monitor via the internet? Answered

I am going to set up a wind-speed monitor at a local beach for kiteboarding. I currently subscribe to ikitesurf.com, but they don't have a monitor at the beach I want. How can I set it up to the Internet so I can get a live feed of the wind speed on my computer at home (home is quite a ways from the beach, as in about 10 miles)?

Question by Duke Luke 9 years ago  |  last reply 9 years ago

Ok, here it goes:   In the description concerning general relativity, the following scenario is depicted:  Jim and Slim are riding a "Tornado" ride (goes by different names, but essentially is a centrifuge that pins you against the outer wall and then drops the floor out from under you. Sometimes calle d PUKE machine). Anyways, looking at the ride from a bird's eye view, one measures the circumference and the radius and we find that the ratio is two times PI or about 6.28.  Now that is from OUR perspective, but from Slim's and Jim's measuring the circumference (so says the book) will give a different answer since they are traveling at high speed (assuming the speed is fast enough to invoke the Lorentz contraction).  Thus, he says in the book that his measurement will come up short and therefore not be the same ratio noted.  I don't doubt this, but I have a problem with not taking into account the lengthing of the circumference because of IT'S motion forward.   Am I missing something?   Why wouldn't the same effect  be proportional to the lengthening of the ruler used to measure the circumference, seeing they are traveling at the same speed?   Am I taking his example TOO FAR (in other words, he is assuming the ride is there but not physical)?   Maybe I over analyze?  :-)

Topic by Goodhart 7 years ago  |  last reply 7 years ago

What is the proper wind speed to find the drag coefficient of a car in a wind tunnel?

This is part of a high school project in which students are comparing the Cd of a full size car with the Cd of a 1:64 (Howwheel size) toy car

Question by Lpgeoteacher 9 years ago  |  last reply 9 years ago

HOW CAN I FIND AIR GUN VELCOCITY FROM WIND SPEED? Answered

I need to know how i can make a extact scienctific calculaion of a air gun velocity based on wind speed, requirements so i can even know the laws and regulations of a exact air gun,bb gun,pellet gun,spring gun,and  airsoft guns #1 it must be extact as science #2 show your equation #3 include inperail units and metric OF BOTH  MUZZLE VECOLITY AND MUZZLE ENERGY while keeping it brief of one of only inperial,one only metric and one with a mixture of both or instead of number 3 you can include with just any unit as of that exact unit type for example kilograms and kilograms force,pounds force and foot pounds,kilogram force to joules be sure it inlcude units of joules,foot pounds,newtons, #4 include the wind speed and what the air gun velcoity of the bullet based on wieght and inlcude the amount per each amount of weight and per each amount of wind speed  I KNOW  IT IS  A BIG ASK HOWVER I NEED TO KNOW THE VELOCITY AND FIREPOWER THEN  I CAN EVEN CHECK THE LAWS

Question by 35Timmy 7 years ago  |  last reply 7 years ago

how use car alternator wind generator circuit please?

Can i make wind mill  at my home use car alternator how given conection for low speed wind what type of conversation in alternator give me deatials with out battery how drawn power from alternator contuiosly direct to 12 v  fan motor  or 12v bulb

Question by shakeelyash 8 years ago  |  last reply 6 years ago

okay i have to make a wind meter for sci class. However it has to have certain things in it. A motion transmission system; A motion transformation system; a speed change. It must also use a variety  parts. Most parts will be made available to me, and i have a few ideas. Such as a pulley system to bring the spinning props movement to a way of changing it to another type of motion is where I'm up to Thanks, Andre

Question by andreblue 8 years ago  |  last reply 8 years ago

possible ac motor generator?

Anybody tried machining strong magnets into the armature of say 10 or 20 hp 3 phase motor. do not  know the output if any but if so then running through a transformer that might have output  of  220 that is actually useable for living, working in a garage. i understand it would have to be overdriven  possibly by multiple blades for torque to reach the ness speed. just curious if you think it might work or not be worth the effort. this is a new field for me.

Question by builditbigger 2 years ago  |  last reply 2 years ago

So I am planning on hooking up a grid tied inverter and generator, I still need to measure the voltage on the incoming lines, but I assume it is 120 ish so I think that is were I will hook the inverter and then it will go back out through the transformers into the lines, is this right?  Now lets say it is hooked to a wind turbine, will the amperage on the generator vary with the speed while still supplying the right voltage, if not how do I compensate for varying wind speed. We are talking 29 kw generator (it is huge, 16 more than the max on my meter, I will obviously consult the electrical company.

Question by jj.inc 7 years ago  |  last reply 7 years ago

Measuring oscillation of a multi tool

I have a harbor freight oscillating multitool that is advertised as oscillating between 10k and 20k oscillations per minute. In reality to speed control goes from 0 opm to an unknown value. I’m trying to set the tool to oscillate at 35 Hz. What is the best way to measure the frequency of the tool and set it to 35 Hz?

Topic by rednax718 1 year ago  |  last reply 1 year ago

I haven't seen anything this on here so I thought I'd step up. Engineers (or anyone who fancies themselves A DIYer) I found a few days back I little some very interesting Wind Powered Rides...six-or-seven-ways-wind-powers-vehicles OK so we know it CAN be done, but can it be done by a DIYer? OK here's my concept, Design and shape are optional but basic components are such: Take a pair of multi-speed Bicycles, their gearing will be the basic propulsion for this vehicle. Take one of the "bikes" and hook up a prop where the pedals "where" and set the wheel output to be higher then the prop speed, this should take care of the foreward movement once going. Now for the initial starting power (Bike 2), this can either be by petal, or by electric (solar/battery- up to you) But the basis for this whole thing is simple energy transfer, if the moving air over the prop causes the drive wheels to go, and by having them geared higher, the vehicle SHOULD move faster the faster you go ..Right? Can I get some math to back this up? it sounds like it would work.

Topic by Green_Primus 10 years ago  |  last reply 8 years ago

how to measure frequency in this circuit?

i want to measure the frequency of this flasher circuit but i always get a frequency close to that of the mains. I am using a wall wart. i changed some of the components to speed up the flashing but the frequency reading stayed the same. to check my multimeter i tried measuring the frequency of mains and the joule thief circuit and it looks like my multimeter is good. how should i measure the frequency in this flasher circuit?

Question by codestroy7 7 years ago  |  last reply 3 years ago

RPM/MPH formula

I'm designing an anemometer with Arduino and I need a formula to figure out the speed at which the rotor turns. I have a rotor with three magnets, spaced 71mm apart, triggering a Hall Effect sensor which the Arduino reads and counts. Now I can't seem to figure out a formula to calculate wind speed from this information. Anybody got an Idea (or the answer?)

Topic by smkoberg 8 years ago  |  last reply 8 years ago

Building a sensor chronograph to measure speed of batted ball

I need a sensor chronograph designed to measure the speed of a batted baseball. It would consist of a frame assembly mounted on a pole in front of home plate in a batting cage. The goal would be for the device to be stationary, able to measure the speed of a batted ball on demand and then displaying it on an LCD positioned 30-60 feet away. It should be automatic and unattended, working without anyone doing anything to activate it other than hitting an oncoming pitch. We are interested in measuring only the batted ball, not the pitched ball from the pitcher or the swing speed of the bat. The measuring area would need to be about 2-6 feet high (depending on how far in front of home plate it is positioned) to accommodate a batted ball that is hit high or low. It should be able to measure the speed of any ball hit fair, from the first base line to the third base line.  The speed of the batted ball would range anywhere from 40 to 130 mph. Since the device would be used on a repetitive, long term basis care would need to be taken during the design to provide for protection from any batted balls that might find their way into the device itself (a piece of screen, chain link or plexiglass installed in front of it?) If you know where I might obtain a working apparatus or might locate someone willing to build one I would appreciate your response to the email address below. Jerry Heath jerry@webcitycybercafe.com

Topic by jerryeheath 7 years ago

is there any way to measure rpms cheaply?

We are making wind turbines in one of my classes and my team is making a tesla turbine as ours. we want a way to measure how fast the disks are spinning. please help.âº

Question by DehLeprechaun 8 years ago  |  last reply 4 years ago

Bamboo wind chimes/ flutes

In the older Robin Hood movie with Kevin Costner, when Robin, Azeem, and Duncan were running from the Sheriff's men, they ran into Sherwood forest.  The forest was reported to be 'Haunted'.  Partway in they heard strange sounds which were discovered to be what I believe bamboo wind chimes that were also flutes or whistles that were activated by the wind.   Anyone know how these could be made?   The main problem I see is that the flute/whistle needs to sound at low wind speed. I have never figures this part out.    Thanks.

Topic by lonepiper 8 years ago  |  last reply 8 years ago

No idea how to make this LED Windmill

OK, I have an idea that sounds kind cool but no working knowledge of electronics. How difficult would it be to make a bank of wind powered LEDS? A circut that progressively lights up more leds as the wind kicks up to a higher speed?

Topic by Eye Poker 11 years ago  |  last reply 11 years ago

Re-winding a PMDC motor?

I have a 12V 5000RPM 15A PMDC motor and even at its top speed I can stop it by hand which is just not right. I took the armature out and here is what I found: Its a 2pole with 16 winding slots, each winding is quite large but theirs only 3 wraps! I know if you half the wire surface area and double the wraps you get half the RPM. Currently the rotor has 3 wraps per coil of 18guage wire with easily enough room for 10x that. What wire size and how many wraps should I re-wind this motor to get maximum torque at 2000RPM?

Question by iceblu3710 9 years ago  |  last reply 9 years ago

HELP DESIGNING WINDING MACHINE

The machine should be able to wind a filament or wire around a beam structure that could measure 40 feet long by a diameter from 5 to 40 inches. A mechanical tensioning system portable and compact for supporting and dispensing fiber filament or wire, to the filament winder with a standard tension range from 1 lbf to 10 lbf. The winding around the beam such be done silmultaniosly in a criss cross pattern to a 45 angle degree. If interested in helping me with the design, my options are open to discuss terms. Please contact me if more information is needed. thank you, munsangv

Topic by munsangv 10 years ago  |  last reply 10 years ago

Winding Method For Guitar Pickups?

I just finished putting together a Savonius wind turbine:https://www.instructables.com/id/ERTAINQF18DW99A/One of the things I really want to work on for the next version is improving the inductance of the coils. Someone told me today that there's a whole community of musicians focussed on wiring their own guitar pickups. He said they do cool stuff with modified sewing machines and the like.Has anyone run across people or projects like this? Do you have you own favorite methods for quickly and effectively making copper coils? I'm thinking something in the 36 gauge thickness with several hundred wraps. So far, I've managed to do okay with 28 gauge wound up in aluminum bobbins by a variable speed drill, but I know there's got to be a better way.

Topic by mikejedw 11 years ago  |  last reply 8 years ago

How can i make a simple wind tunnel apparatus for measuring lift? Answered

I am making a wind tunnel from a fan, some cardboard, duct tape, cups and K'nex to help me design flying machines. How can i make something for measuring lift on a wing about 4 inches long? Also, would it be best to test lift and stability with low, medium or high winds.

Question by aar0nc0le 8 years ago  |  last reply 8 years ago

the distance of others planets measure with tausends of years of light speeds. Answered

How come a ufo creator on board reach to earht.are thair life too long to do it?

Question by tayyareci 10 years ago  |  last reply 10 years ago

Whistling blades on wind direction weather vane

I have a propeller with four blades that acts as a wind direction weather vane. What I would like is for the propeller to make a whistling noise when it is rotated by the wind. Someone told me if I put a small hole or a slit in each of the blades it will make a whistling noisy which should change with wind speed. Can anyone tell me what size hole/slit I would need? Also at what angle would the slit have to be? Or can you tell me any other way to get a whistle from the blades when the wind is blowing? The blades are metal and about 200mm long (400mm overall diameter).

Topic by LouL 10 years ago  |  last reply 4 years ago

LED light from wind turbine

We are playing around with various basic LED lighting from a small wind turbine and have a couple different ideas about how to build.  But we are wondering what the voltage range LED lighting can handle?  Even a small turbine can create a wide range of wattage based on the speed of the wind, at what point are we going to be doing damage to our lighting?  Do we need to come up with some sort of wattage dampener/regulator between the generator and the lights?  Simplicity is key in our design.

Topic by Two Paddles Design 3 years ago  |  last reply 3 years ago

Anemometer and the diameter vs circumference

Various Instructables have been created for building a wind speed anemometer, and nearly all use a bicycle speedometer for the read out. My question is, regardless of the actual diameter, the sensor can be close to the outer rim, or close to the hub, because one revolution is going to be one revolution and register as such on the speedometer. So, setting the speedometer to whatever rim size you desire, the readout would be correct. If you set the tire size to 24", then each time the sensor is tripped, it will show the speed for that tire size.  The same with 27" or 28" tires. The reason I'm asking is because I'm putting together a 'gopher chaser' from Harbor Freight (on sale last weekend for \$1.50) which measures 17 3/8". I have no desire to cut new blades from sheet metal.... Thanks for any input on the issue.

Topic by GrumpyOldGoat 8 years ago  |  last reply 8 years ago

What type of wind turbine design will get me the highest rpm in low wind? Answered

I have a couple ac motors that i am trying to turn into wind generators and they both need fairly high rpms to begin output. Where I live, we have pretty constant wind but not always high wind, so I need a turbine design that will get me the max constant speed for a reasonable price. Any ideas?

Question by Iceman94 9 years ago  |  last reply 8 years ago

Where can I find a wind up mechanism?

I need a winding mechanism for a project. This would be small toy sized. It would be optimal if it were multidirectional winding. Either way winds like a watch. Not a lot of torque so that small hands can wind it, but not as small as a watch winding mechanism or as complex. I would like to add gears to change the speed of the output or torque as needed. Or if anyone knows where a sawing type input such as a worm gear winding. Both of these would be super helpful. I can tear apart winding toys of course. In an information gathering stage right now.

Question by caltman2 5 years ago  |  last reply 5 years ago

Can anybody tell me how to (further) check my VAWT charge controller for malfunctioning?

I have installed a Flexcharge NC25A-12 Charge Controller and an SE440 regulator in line between my VAWT turbine and its rectifier and the 1000 amp inverter. The turbine and controls charge four Trojan 105, six volt, batteries which are hooked in series parallel (two each in parallel, the parallels hooked in series). The turbine is a heavily modified Lenz-2 (vertical axis, three blades with spring-loaded furling & angle of attack control). It generates 108 to 140 Watts (nine amps at twelve volts to ten amps at fourteen volts) at wind speeds of fifteen to twenty five miles per hour. Nevertheless, I'm not able to charge the batteries. I think the Flexcharge charge controller is stuck, that inasmuch as the controller’s "Multi Function Indicator" function does show when batteries are low, when voltage from the system is low, and when charging is occurring (flashing and steady green light), but has never shown "divert" (to a heat sink). More, I have never been able to get the batteries to hold anything close to their individual 225-250 amp-hour rating. It's beginning to look like the batteries, purchased new originally, have sulfated on account of the charge controller panel not working. I note in using my multimeters that the cable at the heat sink indicates 2.85 volts, even when the batteries are down to 11.9 volts, and when the charge controller is not indicating "divert." When, moreover, an external battery charger (the automotive kind) is hooked in line and in lieu of the wind turbine and rectifier (these being disconnected from the controller, regulator, batteries, and dump load), the batteries indicate full charge on both hand-held multimeters and turbine system voltmeter and ammeter, but the charge controller does not indicate “divert” to the dump load heaters. Any ideas will be much appreciated. Thanks!

Question by taiosan 7 years ago

Reducing speed / RPM of pedestal fan

I have a 400 mm pedestal fan rated for 230V 50Hz AC, 120W with minimum 2200 RPM which uses motor coils winding for speed regulation. Its speed and noise is very much even at lowest setting. I want to reduce its speed even further. I am thinking of three options - one - changing the OEM fitted 3.00 micro-farad 440V capacitor with 1.5 or 2.0 micro-farad 440V capacitor, second - using a capacitance based speed regulator (used with ceiling fans) and the third - using a resistance based speed regulator (least preferred option though). Please tell which option will work fine without doing any harm to motor coil? Any other options are highly welcome.

Question by sharmavk83 10 months ago

Can a hard drive motor be used to generate electricty?

I have built a small Lenz type VAWT and wanted to used a hard drive motor I had laying around since it has great bearings and a the disc provide a great way to mount the air foils.  I believe it would generate 3 phase power but I am not sure how to wire it.  three of the six wires have continuity - are there three specific coils?  I have no information on the motor itself.  Would the motor have to spin at high speeds to really generate anything?

Question by gearhead460 6 years ago  |  last reply 6 years ago

Blade Tip Power System for wind energy...

I'm looking at adding a not too obtrusive wind generator to a house I just bought. One of the best I have come across is the honeywell BTPS (Blade Tip Power System) - it isn't as sleek looking as a lot of the turbines I am looking at, but it seems like a good concept to me. http://www.earthtronics.com/honeywell.aspxI can't believe that this company is the first to come up with the concept; has anyone here seen any other similar systems, designed to run in the lower speeds/altitudes common in a smaller residential setup, but generating decent power?

Topic by karossii 9 years ago  |  last reply 9 years ago

how do you measure speed of a vehicle using hall effect sensor?

I mean where do you fix the sensor and how is it done!

Question by Nr-Think different 6 years ago  |  last reply 6 years ago

VAWT a new way to wind generation

Guys need help to realise its feasiblity and pros & cons. This project will comprise of a renewable energy source which is controlled by TI msp430 controller by closed loop system. This renewable energy source will use a magnetically levitated vertical axis wind turbine with single phase permanent magnet alternator made by our team. There will be 3 stationary wind guide vanes/flaps of concave shape on the outer periphery of turbine. These vanes will be controlled by dc gear motor for constant wind flow and protection against high speed winds. Using perturb & observe MPPT algorithm on DC-DC boost converter, constant DC voltage for GRID integration is made. A lower energy Bluetooth module will send data on user computer about whole system parameter, hence making the whole system to be smart and hence data is saved in database. https://www.youtube.com/watch?v=fC5hYLjhO9U

Topic by nitcool 4 years ago  |  last reply 4 years ago

VAWT a new way to wind generation

Guys need help to realise its feasiblity and pros & cons. This project will comprise of a renewable energy source which is controlled by TI msp430 controller by closed loop system. This renewable energy source will use a magnetically levitated vertical axis wind turbine with single phase permanent magnet alternator made by our team. There will be 3 stationary wind guide vanes/flaps of concave shape on the outer periphery of turbine. These vanes will be controlled by dc gear motor for constant wind flow and protection against high speed winds. Using perturb & observe MPPT algorithm on DC-DC boost converter, constant DC voltage for GRID integration is made. A lower energy Bluetooth module will send data on user computer about whole system parameter, hence making the whole system to be smart and hence data is saved in database. https://www.youtube.com/watch?v=fC5hYLjhO9U OR YOU CAN SEE https://www.instructables.com/id/Building-a-new-type-Vertical-Axis-Wind-Turbine-VAW/

Topic by nitcool 4 years ago  |  last reply 4 years ago

Magnetic switch to USB?

Hi, 1st post hope you can help! I'm trying to find a way of getting analog data (from an exercise bike) and store it onto a computer in a text file so I can manipulate it and work out averages etc. I thought of having a magnetic switch on the pedal so that everytime the pedal rotates I can store the time thus giving me the speed. Does anyone know if such a cable already exists or if not how to go about creating one? Also if anyone has a better way of getting the data I'd love to hear from you. Many thanks Adam

Topic by adamt_069 10 years ago  |  last reply 10 years ago

Maintaining a stable voltage on a wind turbine?

Every couple weeks a new instructable comes up on some green energy thing or another, but one I am really interested in is wind.  The problem I see is that with wind ranges from 5 - 25 mph, the voltage change is extremely problematic.  When I see people putting permanent magnets on alternators for use with wind, it seems ridiculous.  Even if you are using an inefficient battery-storage off-grid system, you still need to maintain 12-15 volts to charge your battery, and an alternator is made to do that by varying the magnetic power.  Now I understand the extremes of a alternator's voltage regulator are likely fairly narrow, but still quite useful in generating wind energy.  What I am looking at is 3-5kw of grid-tied power.  This is great and all, and possible in for me, but I don't see how I could maintain a stable enough input for it to work.  Most inverters are for solar power and aren't grid tied. The next most common are grid tied solar which take 12v DC and scale it to 115 ac across three phases.  Finding a grid-tie 5kw 3 phase in and out ac grid tie inverter is extremely hard, but not impossible.  The only thing that is impossible is finding one that can handle highly unstable voltages.  So the options I am left with are using a variable transformer to bring the wind power down to 12v and then rectifying it, then pumping it through an inverter which leaves me with 70 - 80 % of the original power.  My other option is to, like a car alternator vary the rotor voltage to maintain the desired end voltage.  The one problem I see with this is that there is a large amount of potential energy not tapped.  For example lets use 1 as the relative output as well as the input to generate a magnetic field.  If the speed is 1 then both in and out are 1.  If the speed is 2 then the in will be .5 now the out should stay at 1.  But if the in had remained at 1, then the out would be 2 so essentially you are losing half of your potential energy.  This isn't a problem in cars because they aren't tapping the maximum power possible. All the time, they don't need it.  This is a problem with wind turbines, so is there a way around this?  What wold you recommend to do for grid-tied wind power.

Question by jj.inc 5 years ago  |  last reply 5 years ago

Old Dunlap Model 103-0602 wood lathe Answered

Hi, I have an old Dunlap Model 103-0602 wood lathe. It has step pulleys to adjust the speed. One pulley is on the lathe head and turns the center shaft. The other pulley is on the shaft of the motor. The motor is 1/3 HP ,  1725 rpm's and has a 5/8 shaft. The pulley on the motor shaft is       4", 3 1/4",  2 1/2" and 1 3/4 " .  I am having trouble measuring around the pulley on the head of the lathe are they usually the same size? Well can anyone help me? Thanks Frank

Question by tall1smokey 8 years ago  |  last reply 4 years ago

How would I choose the most efficient electric motor to use as a generator for a small wind turbine?

I have a school project to build a small wind turbine (approx. 8" propeller diameter) to produce the maximum out DC voltage possible.  We are still deciding between a horizontal & vertical orientation (leaning towards vertical) but we need some help on understanding what we should look for in the motor/gear setup in order to produce the maximum possible voltage at relatively low wind speeds.  What should I look for and where would be a good place to buy/scavenge these parts? Thanks!

Question by ddrocketman 8 years ago  |  last reply 8 years ago

Compare the older posts of Magnet generators "instructable-type" to the current posts - Is this way still competitive?

I love you guys - keep it up!  I am the Hippie often referred to, according to my little brother, Dirt. (I'm older than Dirt...) Over a year ago I studied this fellow while recovering from being run down on my bike by a hit and run car doing 65MPH. The thing that keeps coming back to me is that I always see a multitude of ceiling fans for practically free. Also he addresses the over speed topic very well too. HTTP://www.youtube.com/user/muddymuddymuddmann?feature=watch

Question by miscexpert 7 years ago  |  last reply 7 years ago

how much amp Min kota troll motors uses per hour? Answered

I need a boat that will be powered by a two wind mills and I will be using a Min kota troll motor to move it. I will charge the battery with AC day and night and only use it few hours a day. I will use a 100Ah deep cycle marine battery, How much these fishing motors use them in full throttle speed? thanks

Question by celalboz 9 years ago  |  last reply 9 years ago

Tracking down the speed problems on a laptop.

Topic by Javin007 8 years ago  |  last reply 7 years ago

Is there a way to build a simple tachometer without a microcontroller? Answered

I would like to measure the speed of a motor that i have, but have nothing to do it with. If there is a simple kit (cheaply), then please point me to that. I don't want to have to program a microcontroller, though.

Question by qwertyboy 9 years ago  |  last reply 9 years ago

Whistling blade on wind direction weather vane

I have a propeller with four blades that acts as a wind direction weather vane. What I would like is for the propeller to make a whistling noise when it is rotated by the wind. Someone told me if I put a small hole or a slit in each of the blades it will make a whistling noisy which should change with wind speed. Can anyone tell me what size hole/slit I would need? Also at what angle would the slit have to be? Or can you tell me any other way to get a whistle from the blades when the wind is blowing? The blades are metal and about 200mm long (400mm overall diameter). Thanks for any help. Lou

Topic by LouL 10 years ago  |  last reply 7 years ago