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designed his own interrupter circuit for delivering shocks to patients from a voltaic cell through an induction coil. Previously, the interrupter had been a mechanical device requiring the physician to manually turn a cog wheel, or else employ an assistant to do this. Bird wished to free his hands
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which could output only the make, or only the break currents by a mechanism consisting of two spoked wheels. Bird also produced a uni-directional interrupter using a mechanism we would now call split-rings. The date of Bird's design is uncertain but may predate
Letheby's. Both designs suffered
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slightly earlier in 1838 but Bird's work was entirely independent. Although there is little in common between the two interrupter designs, Page takes the credit for being the first to use permanent magnets in an automatic interrupter circuit. Bird's (and Page's) interrupter had the medically
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is so arranged that a permanent magnet underneath the arm then repels the pivot arm and causes the circuit to break, but the prongs at the other end of the pivot arm then close an identical circuit at that end and the procedure repeats endlessly. The output of the interrupter is fed to an
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operations, although the current was substantially less during the make operation than the break (current is only supplied at all while the switch is dynamically changing). Treatment often required that current was supplied in one specified direction only.
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from the disadvantage that automatic operation was lost and the interrupter had to once again be hand-cranked. Nevertheless, this arrangement remained a cheaper option than electromagnetic generators for some time.
141:(five times per second). The faster the interrupter switches, the more frequently an electric shock is delivered to the patient and the aim is to make this as high as possible.
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to better apply the electricity to the required part of the patient. His interrupter worked automatically by magnetic induction and achieved a switching rate of around
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for the purpose of converting a steady current into a changing one. Frequently, the interrupter is used in conjunction with an
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filled recesses. This completes a circuit which energises a coil around the iron pivot arm and functions as an
338:"A description of a new electro-magnetic machine adapted so as to give a succession of shocks in one direction"
84:, the first transformer, which was used to produce high voltage pulses in scientific experiments and to power
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Pulvermacher, Isaac Lewis "Improvement in voltaic batteries and apparatus for medical and other purposes",
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Frankenstein's
Children: Electricity, Exhibition, and Experiment in Early-nineteenth-century London
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273:"Observations on induced electric currents, with a description of a magnetic contact-breaker"
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Lectures on
Electricity and Galvanism, in their physiological and therapeutical relations
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operated by motion of the patient's limbs. One example of such a device is found in the
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disadvantageous feature that current was supplied in opposite directions during the
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of gasoline engines, which served to periodically interrupt the current to the
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in electrical engineering is a device used to interrupt the flow of a steady
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Other early interrupters worked by clockwork mechanisms or (non-magnetic)
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A rather more cumbersome interrupter was constructed by the
American
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action. The largest industrial use of the interrupter was in the
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297:"The collateral sciences in the work of Golding Bird (1814–1854)"
96:, around the turn of the 20th century. Its largest use was the
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which greatly increases the voltage applied to the patient by
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producing high voltage pulses which create sparks in the
72:(coil of wire) to produce increased voltages either by a
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A modified version of the interrupter was produced by
35:: The prongs at the end of the pivoted arm dip into
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30:'s original sketch of his interrupter circuit.
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116:. It is still used in this application.
307:, iss.4, pp. 363–376, October 1969.
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333:, London: Spottiswoode & Co. 1856.
330:Electricity, Magnetism, and Acoustics
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292:, Wilson & Ogilvy, London, 1847.
314:, Princeton University Press, 1998
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344:, pp. 858–859, 13 November 1846.
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90:spark gap radio transmitters
18:Interrupter (disambiguation)
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353:, issued 1 February 1853.
342:London Medical Gazette
277:Philosophical Magazine
220:Bird (1838), pp. 18–22
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367:Electrical components
163:Letheby's interrupter
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279:, pp. 18–22, no.71,
248:Letheby, pp. 858–859
16:For other uses, see
100:or "points" in the
326:Lardner, Dionysius
240:Morus, pp. 250–251
231:Morus, pp. 250–251
186:Pulvermacher chain
145:Page's interrupter
125:Bird's interrupter
76:effect or through
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350:U.S. patent 9,571
310:Morus, Iwan Rhys
259:Pulvermacher, p.2
45:magnetic polarity
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336:Letheby, Henry
301:Medical History
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266:Bibliography
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151:Charles Page
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131:Golding Bird
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28:Golding Bird
120:Medical use
114:spark plugs
102:distributor
94:X-ray tubes
78:transformer
62:interrupter
54:transformer
33:Description
204:References
86:arc lamps
361:Category
244:Lectures
192:See also
74:back emf
70:inductor
104:of the
56:action.
43:. The
37:mercury
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305:vol.13
281:vol.12
242:Bird,
316:ISBN
60:An
363::
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138:Hz
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