Important Collectors’ Wristwatches, P...

Geneva, Mandarin Oriental Hotel Du Rhône, May 13, 2007

LOT 65

?The First Transistorized ATO Electric Regulator? Léon Hatot, Fabricants, Paris, (ATO), No. 205627. Made in 1953-54. Fine and very rare, electric, precision ?master? wall regulator with center seconds and half-second pendulum, the first model of electric clock with transistor activated power transmission.

CHF 1,500 - 2,500

EUR 900 - 1,500 / USD 1,200 - 2,000

Sold: CHF 3,540

C. Rectangular, patinated silver painted aluminum backboard with connections for slaves at the top, four wall leveling screws, perspex cover. D. Circular, two-tone, white chapter ring with black baton hour indexes and minute seconds divisions, matte silvered borders. Black baton hour and minute hands, red center seconds hand. M. Rhodium-plated, transistorized power transmission, half-second pendulum with spring suspension, large cylindrical weight with regulation adjustment, double magnetic bars, coil and Foucault regulator, fine magnetic adjustment lever at the bottom right. Dial and movement signed. Dim. 47 x 26.5 x 9.5 cm. Property of a French Gentleman

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Grading System
Grade: AA

Very good

Case: 4-7



Movement: 3*


Overhaul recommended, at buyer's expense

Dial: 3-01


HANDS Original


The present lot is one of the first ATO transistorized clocks of 1953-1954. The construction is largely the same as earlier models except that the mechanical contact normally activated by the pendulum is replaced with a second coil and transistor. This coil does not receive any current, but generates it by the passgage of the magnet through its center. The weak current generated by this action activates the transistor, which allows current to pass from the battery to the motor coil. This system was invented by M. Lavet and J. Dietsch.