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    Vertical wind turbine with two concentric rotors

    Thank you. Perhaps my design would not work and is not worth it. I made several attempts to draw it and none of my designs considered things that you mentioned.
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    Vertical wind turbine with two concentric rotors

    I am aware of the theoretical limit of the wind turbine's efficiency. I am also aware that the outer turbine/blade set would increase the wind velocity for the inner turbine. The main parameter that I think about is cost. Perhaps I am going to build a small toy at first. A DC motor and a...
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    Vertical wind turbine with two concentric rotors

    Hello. For a long time, I wanted to build a wind turbine prototype that would have two concentric rotors. The design was inspired by an automotive torque converter, used with automatic transmissions. This device would have an external rotor that would be coupled to one generator and an internal...
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    Synthetic fibers (rope) that absorb water and shorten

    That part I already had figured out: material would have been behind the valve - water seeps out - valve opens, valve opens, new water fills the material and it expands and closes the valve. A new system works on an even better principle as it is very easy to control how much water goes to the...
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    Synthetic fibers (rope) that absorb water and shorten

    I found another solution to this engineering problem. Thank you for your answers. The solution is that wet fibers would keep air from flowing through as fast as dry fibers, thus preventing the automatic bell syphon from discharging more water until fibers drie out. This device is going to be...
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    Synthetic fibers (rope) that absorb water and shorten

    The super absorbent polymer can retain water, but how easily does it let go of that water?
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    Synthetic fibers (rope) that absorb water and shorten

    Hello. I have an engineering idea, an invention. I want to make a watering valve for plants that opens the water when the soil moisture content is too low. I am looking for a material that (1) would not rot, and (2) absorb water and contract at a significant rate to open a valve (millimeter...
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    Two eccentric flywheels run on same axis

    I am trying to do math but I cannot tie abstract formulas from Wikipedia to the problem I am solving. It is too difficult. I know what those formulas stand for and I know what I want to find but I don't know how to connect the two.
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    Two eccentric flywheels run on same axis

    Maybe I don't need a counterweight. Would it still cause the flywheels to act the same throughout the range of speeds? What about the fact that the system will be allowed to vibrate and that the eccentrics will not rotate about exactly around a center point? They will rotate around some point...
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    Two eccentric flywheels run on same axis

    I am talking about Rotational vibration cancellation. I want to exclude the angular rotations from two flywheels being slightly off center. Or minimize them. The idea is to make most of the mass of one flywheel surround most of the mass of another flywheel. So their masses spin along the...
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    Two eccentric flywheels run on same axis

    I was asked to build an experimental setup for one of my friends and I did it successfully. The setup included two eccentric flywheels, spinning in opposite directions on the shafts of two stepper motors that were facing each other. I 3D printed a pair of identical eccentric flywheels and...
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    Transformer & Mesh Current Problem

    It would be nice if you give me the right solution so I can study it. I read the wikipedia article and I don't understand anything.
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    Transformer & Mesh Current Problem

    So is it (Lesser voltage - Greater voltage) / resistance that separates two voltages of two nodes? Or what is the logic in terms of what voltage is subtracted from what voltage before the division?
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    Transformer & Mesh Current Problem

    Thank you. Zero resistance - thats interesting. Far from what I would consider "ideal". Thank you, Rude Man, Thank you The Electrician.
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    Transformer & Mesh Current Problem

    I am a grad student and I am asking out of interest because I forgot all this. For sum of voltages to work, transformer winding #1 has 0 resistance or infinite resistance?
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    Transformer & Mesh Current Problem

    If I short the secondary, the current through the short will be infinite even though it is 1/2 of the primary current? Thanks. This is my last question because I still don't understand what I am doing.
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    Transformer & Mesh Current Problem

    I know that. Thank you for helping me. Transformer winding 1 has no resistance or infinite resistance? What is the current flowing through? Thanks.
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    Transformer & Mesh Current Problem

    V1 = {I1 + [( (V1-V3)/8Ω)*4Ω)-60} * (-1) V2 = (-2) * {I1 + [( (V1-V3)/8Ω)*4Ω)-60} I1 = ( (V1-V3)/8Ω) *4Ω -60+V1 I2 = { ( (V1-V3)/8Ω) *4Ω -60+V1 }/2 I will finish V3 tomorrow. Than I solve a system of equations by substitution and it is solved? Thank you.
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    Transformer & Mesh Current Problem

    How can I sum currents in every node if there are two different current sources and they are tied with a resistor that has effect on both nodes? To sum currents to zero they all need a sign (+ or -). I don't understand this either. I took a class on this to get a piece of paper that determines...
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    Transformer & Mesh Current Problem

    But I don't know how to treat the 8 ohm resistor that this problem is about. It is neither part of primary nor the secondary circuit.
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    Transformer & Mesh Current Problem

    So can I use this model to solve a problem that Cetullah posted?
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    Transformer & Mesh Current Problem

    Can this circuit be represented like this at avrious stages of the AC cycle? We are solving for RMS? "Rectified" voltage on that resistor. Am I correct? AC on the primary and on the secondary of a transformer is in phase? http://en.wikipedia.org/wiki/Transformer: [Broken] "With sinusoidal...
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    Intense light igniting a mixture of fuel and air

    Sorry. I am asking about hydrocarbons. Alcohol, most likely.
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    Transformer & Mesh Current Problem

    I would use a SPICE simulator for that, personally. Even if I know how to solve for resistor grids, what resistance do transformer windings offer? What is the shift in current /voltage in this 'ideal' transformer? Thanks.
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    Intense light igniting a mixture of fuel and air

    Homework Statement We are working on a project for a class. I was given a part of the project where focused light is used to burn off carbohydrates. I want to know names of the following values so I can look them up and their relationships. Energy required to start combustion at atmospheric...
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    Transformer & Mesh Current Problem

    What do the dots mean? Is it CW vs CCW windings? Positive becomes negative and negative becomes positive?
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    Where would I shop for safe to drink lab alcohol?

    Extractions are used in herbal medicine for example. This kind of therapy is not respected in this country but it doesn't mean that I will stop what I am doing. I want alcohol without any traces of impurities. Since finding grape alcohol is hard around here as well I don't know what to do.
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    Where would I shop for safe to drink lab alcohol?

    I read the PDF but it doesn't answer my question since I am not trying to escape taxes, resell alcohol or buy industrial amounts of it. I am trying to find alcohol that was purified beyond what I can find in liquor stores. If it is still classified as liquor, I don't mind that.
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    Where would I shop for safe to drink lab alcohol?

    I can't find a lab supplier that sells alcohol on the Internet. Nobody advertises anything like that. I don't understand how this market works. Liquor stores don't sell pure alcohol either. Only Everclear for rednecks.
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