alternated polarity

1) полярность

2) мат. поляритет, полярное преобразование

3) полярная корреляция

4) полярное соответствие

5) полная противоположность

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- absolute polarity

- alternated polarity

- degenerate polarity

- dual polarity

- elliptic polarity

- hyperbolic polarity

- incomplete polarity

- nonsingular polarity

- null polarity

- orthogonal polarity

- point-prime polarity

- prime-point polarity

- reversed polarity

- symplectic polarity

- trilinear polarity

- uniform polarity

- unitary polarity

Чередованный

SUBJECT AREA: Electronics and information technology, Horology

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After serving an apprenticeship with a clock-maker in Blaubeuren, Hipp worked for various clockmakers before setting up his own workshop in Reutlingen in 1840. In 1842 he made his first electric clock with an ingenious toggle mechanism for switching the current, although he claimed that the idea had occurred to him eight years earlier. The switching mechanism was the Achilles' heel of early electric clocks. It was usually operated by the pendulum and it presented the designer with a dilemma: if the switch made a firm contact it adversely affected the timekeeping, but if the contact was lightened it sometimes failed to operate due to dirt or corrosion on the contacts. The Hipp toggle switch overcame this problem by operating only when the amplitude of the pendulum dropped below a certain value. As this occurred infrequently, the contact pressure could be increased to provide reliable switching without adversely affecting the timekeeping. It is an indication of the effectiveness of the Hipp toggle that it was used in clocks for over one hundred years and was adopted by many other makers in addition to Hipp and his successor Favag. It was generally preferred for its reliability rather than its precision, although a regulator made in 1881 for the observatory at Neuchâtel performed creditably. This regulator was enclosed in an airtight case at low pressure, eliminating errors due to changes in barometric pressure. This practice later became standard for observatory regulators such as those of Riefler and Shortt. The ability of the Hipp toggle to provide more power when the clock was subjected to an increased load made it particularly suitable for use in turret clocks, whose hands were exposed to the vagaries of the weather. Hipp also improved the operation of slave dials, which were advanced periodically by an electrical impulse from a master clock. If the electrical contacts "chattered" and produced several impulses instead of a single sharp impulse, the slave dials would not indicate the correct time. Hipp solved this problem by producing master clocks which delivered impulses that alternated in polarity, and slave dials which only advanced when the polarity was changed in this way. Polarized impulses delivered every minute became the standard practice for slave dials used on the European continent. Hipp also improved Wheatstone's chronoscope, an instrument that was used for measuring very short intervals of time (such as those involved in ballistics).

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