A French electric industrial master clock made by ATO, dating from the 1950s. This is a very early example of the use of transistors in clocks.
This is a very accurate clock, having a half second pendulum. The French railways used ATO clocks for their excellent timekeeping. A master clock sent impulses to a series of slave clocks, ensuring conformity of timekeeping within a public space or workplace.
This example is also an interesting clock to behold, with visible movement of both the red centre seconds hand and the swinging pendulum.
The dial and movement are mounted on a hammered effect green-blue metal sheet c.20″ x 10½”, with the original removable curved perspex cover.
It has a clear 8″ two-tone Arabic dial, with a red centre seconds hand.
The moulded perspex cover hangs by a metal bar, with securing clips on either side in the middle for removal. This one has a very small amount of damage on the bottom right-hand corner, shown in a photo.
In 1954, the first transistorized clock was designed by Lavet, a director at the Hatot Company. The previous ATO clocks had a mechanism that physically opened and closed a switched circuit to provide the impulse to the magnet through an activated coil. The use of the transistor allowed for the removal of the switch gear, thus overcoming well documented unreliability problems. The impulse coil was now activated by a second transistorised coil.
The clock is to be sold fully overhauled and with a 3 year guarantee.