Rare Antique 1800 ' S Dynamo Teaching Model With Galvanometer Bipolar Motor
Item History & Price
| Reference Number: Avaluer:262463 | Original/Reproduction: Original |
Wow, this is an odd one. I can only find a few photos of these things, and only one is of this exact style and it is a line drawing in a book. This looks to be a very early first style example. In a 1909 book it is called "the Ideal Dynamo". Made by WM Gaertner & Co Chicago Later styles, apparently are called a" dynamo analysis apparatus" It appears it was used for teaching dynamo theory. It looks to be complete and have all of the parts.&n...bsp; Most all of the black and silver parts are Brass, the magnets are iron. All parts move freely. If you actually wanted to use it, my guess is it would need a new spring and some restoration. Information below from http://physics.kenyon.edu
Dynamo Model "The ideal dynamo shown [below] is arranged so that at everyrevolution of the crank the ratchet is lifted, allowing a spring to rotatethe coil through 10°. The terminals of the coil are connected to separatelyinsulated copper rings attached to the shaft. Copper strips or "brushes"bearing upon this ring are connected to a moving-coil galvanometer. Asthe coil moves through any ten-degree interval, an E.M.F. is induced whichcorresponds to the mean angular displacement of the coil from its originalposition. Since the total resistance through which this E.M.F. causes acurrent to flow remains the same through the experiment, the quantity ofelectricity passing through the galvanometer, and therefore the galvanometerdeflection, is proportional to this E.M.F. If the observed deflectionsare plotted as ordinates and the corresponding values of the angular displacementsas abscissas, the smooth curve drawn through these points will in generalhave practically a sine form.
From Robert Andrews Millikan and John Mills, A ShortUniversity Course in Electricity, Sound and Light (Finn and Company, Boston, 1908) pg 134 (SEE LAST PHOTO)
About 11 inches long, 8lbs, horseshoe magnets still appear to have some power.
NO INTERNATIONAL BIDS without priorapproval!! (My Standardebay Disclaimer) . No one can be expected to be an expert at everything. I havedone my best to describe the item accurately, and in an honest opinion. It ishighly suggested you look at the pictures, and read the descriptions todetermine if the item is what you want. What you see in the photos is what you get!! If you are still unsure, please ask questionsbefore you bid. I will only accept returns if the itemis not as described, most of the items I sell are antiques and do show signs ofage and handling. WHAT YOU SEE IN THEPICTURES IS WHAT YOU GET! I AM NOT ANEXPERT IN EVERYTHING! IF YOU HAVE QUESTIONS ASK!! High bidder pays actualpacking/shipping/insurance costs and agrees to submit payment within 3 days ofclose of auction. ***** Most items ship within 3 business days or less One last thing! Please don’twait until the last minute to ask questions, I only get my email once aday!
Dynamo Model "The ideal dynamo shown [below] is arranged so that at everyrevolution of the crank the ratchet is lifted, allowing a spring to rotatethe coil through 10°. The terminals of the coil are connected to separatelyinsulated copper rings attached to the shaft. Copper strips or "brushes"bearing upon this ring are connected to a moving-coil galvanometer. Asthe coil moves through any ten-degree interval, an E.M.F. is induced whichcorresponds to the mean angular displacement of the coil from its originalposition. Since the total resistance through which this E.M.F. causes acurrent to flow remains the same through the experiment, the quantity ofelectricity passing through the galvanometer, and therefore the galvanometerdeflection, is proportional to this E.M.F. If the observed deflectionsare plotted as ordinates and the corresponding values of the angular displacementsas abscissas, the smooth curve drawn through these points will in generalhave practically a sine form.
From Robert Andrews Millikan and John Mills, A ShortUniversity Course in Electricity, Sound and Light (Finn and Company, Boston, 1908) pg 134 (SEE LAST PHOTO)
About 11 inches long, 8lbs, horseshoe magnets still appear to have some power.
NO INTERNATIONAL BIDS without priorapproval!! (My Standardebay Disclaimer) . No one can be expected to be an expert at everything. I havedone my best to describe the item accurately, and in an honest opinion. It ishighly suggested you look at the pictures, and read the descriptions todetermine if the item is what you want. What you see in the photos is what you get!! If you are still unsure, please ask questionsbefore you bid. I will only accept returns if the itemis not as described, most of the items I sell are antiques and do show signs ofage and handling. WHAT YOU SEE IN THEPICTURES IS WHAT YOU GET! I AM NOT ANEXPERT IN EVERYTHING! IF YOU HAVE QUESTIONS ASK!! High bidder pays actualpacking/shipping/insurance costs and agrees to submit payment within 3 days ofclose of auction. ***** Most items ship within 3 business days or less One last thing! Please don’twait until the last minute to ask questions, I only get my email once aday!
