- Item 74519 - Sangamo Type H electric meter, 1911
- Contributed by Maine Historical Society
- Item 74519
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- *Credit line must read: Collections of Maine Historical Society
This model had been in development for some time before its introduction in 1911, but Sangamo had to wait for the Tesla patents, owned by Westinghouse, to expire.Show Details
This induction-type meter uses fluctuations in magnetic fields to turn the rotating disk, while a drag, or lag, magnet keeps the disk turning at a rate proportional to the current.