From S.H.O.
Parts Dimensions
Coil 1
Wire type
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Rated temperature
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Coil gauge
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Wire length
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Number of turns
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Coil 2
Wire type
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Rated temperature
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Coil gauge
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Wire length
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Number of turns
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Magnets (Group 1)
Magnet material
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Magnet grade
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Pole width 1 (if rectangular)
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Pole width 2 (if rectangular)
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Pole diameter (if circular)
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Length along magnetization
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Magnets (Group 2)
Magnet material
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Magnet grade
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Pole width 1 (if rectangular)
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Pole width 2 (if rectangular)
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Pole diameter (if circular)
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Length along magnetization
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Shaft
Length
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Diameter
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Alloy
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Threaded (Y or N)
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Thread Pitch
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Fan
Diameter
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Blade Pitch
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Number of Blades
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Material
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Typical use
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Measurements
Pre-run testing on ___ /___ / 20___
Rotational speed □ Tachometer used
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Induced AC voltage □ Root mean square
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0 RPS = 0 RPM
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1 RPS = 60 RPM
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2 RPS = 120 RPM
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3 RPS = 180 RPM
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4 RPS = 240 RPM
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5 RPS = 300 RPM
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6 RPS = 360 RPM
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7 RPS = 420 RPM
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8 RPS = 480 RPM
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9 RPS = 540 RPM
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10 RPS = 600 RPM
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__ RPS = ___ RPM
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__ RPS = ___ RPM
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__ RPS = ___ RPM
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__ RPS = ___ RPM
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Test run on ___ /___ / 20___
Time HH:MM AM/PM
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Current Amps
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Rotation Speed RPM
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Air speed □ __/ s □ __/ h
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Air Temps. (4 Max) □ °C □ °F
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Coil Temps. (2 per coil) □ °C □ °F
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____:____ __M
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Not running
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Not running
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Not running
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____ _____ | _____ ____
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____:____ __M
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Not running
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Not running
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Not running
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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____ _____ | _____ ____
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____:____ __M
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____:____ __M
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____ _____ | _____ ____
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____:____ __M
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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____:____ __M
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____ ____ ____ ____
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____:____ __M
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____ _____ | _____ ____
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____:____ __M
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____ _____ | _____ ____
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____:____ __M
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Not running
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Not running
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Not running
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____ ____ ____ ____
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____ _____ | _____ ____
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____:____ __M
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Not running
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Not running
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Not running
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____ _____ | _____ ____
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Unit Conversions
Why care about inches?
- In the Imperial system of measurement, inches are usually divided into halves, which means base 2 for anything shorter than 1 inch. 1/2", 1/4", 1/8", and 1/16" are commonly used measurements.
- If you view the listings for block neodymium magnets from a supplier such as Magnet4less.com, Magnet4sale.com, or KJmagnetics.com, you can find out that magnet lengths, widths, and heights are in inches.
- While the metric system is clearly more useful for scientific purposes, the base 2 system used for sub-inch imperial mesaurements is actually quite helpful for making interlocking assemblies composed of different-sized blocks.
Useful
- 1 inch (in) = 2.54 centimeters (cm)
- 1 foot (ft) = 0.3084 meters (m)
- 1 cubic inch (in³) = 16.39 milliliters (mL) = 1.639 * 10^-5 cubic meters (m³)
Logical
- 1 amp-hour (Ah) = 3600 Coulombs (C)
- 1 milliamp-hour (mAh) = 3.6 Coulombs (C)
- 1 cubic meter (m³) = 10^3 cubic decimeters (dm³) = 10^6 cubic centimeters (cm³)
- 1 cubic meter (m³) = 10^3 liters (L) = 10^6 milliliters (mL)
Strange
- 1 gallon (gal) = 2^2 quarts (qt) = 2^3 pints (pt) = 2^4 cups (C) = 2^7 fluid ounces (fl oz.) = 2^8 tablespoons (Tbps)
- 2000 Calories (kCal) = 2.324 kilowatt-hours (kWh)
- 100 Calories per 2 Tablespoons (kCal/Tbsp) = 3,930 watt-hours per liter (Wh/L)
Surprising
- Energy of a neodymium magnet at 1.5 Tesla (T)
- (1.5 Tesla)^2/(2*4pi*10^-7 Henries per meter) * (1.639 * 10^-5 cubic meters) = 14.67 Newton-meters (Nm) in a cubic inch
- Conclusion: A cubic inch neomagnet, if depleted of its magnetic energy, could not even run a 15 watt light bulb for one second.
- Energy of a AA Battery (7.7 mL) at 1.5 Volts (V) and 2000 milliamp-hours (mAh)
- (1.5 Volts * 7200 Coulombs) * (16.39 ml / 7.7 mL) = 22,990 Newton-meters (Nm) in a cubic inch (> 1,500x)
- Conclusion: The magnetic field energy of a magnet, if depleted, would yield less than 0.1% as much energy as a battery of the same size.
- Energy of Peanut Butter at 100 Calories per 2 Tablespoons
- (3,930 Wh/L) * (3600 Nm/Wh) * (0.01639 L) = 231,900 Newton-meters (Nm) in a cubic inch (> 15,000x)
- Conclusion: Food sources of energy can be substantially more energy dense than typical battery tech.
What makes this surprise useful?
- Sometimes online a person makes the argument that a machine is powered by magnets and that such magnets would provide energy as long as they last.
- This argument can sometimes be used to explain away significant amounts of net work with the notion that such magnets are being spent through demagnetization.
- In light of the fact that the energy density of neodymium magnets is less than 0.1% of the energy density of simple Alkaline battery chemistry, powering motors by utilizing the weakening of the magnet field of otherwise permanent magnets is not a plausible mechanism for explaining any output of significance.
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HQ ● Glossary ● April 2016 Presentation