This is a 1960s Junghans ATO-MAT S clock that uses a transistor circuit to keep the oscillation of its balance wheel running (identical principle as in the Benrus Electronic Citation - just in bigger).
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For its time a modern design with good quality components - it can still work today.
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The "slide-in" clock module and dial.
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Hands taken off.
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The movement removed from the dial. On the left is a hack lever to stop the movement of the balance wheel and thus of the movement itself (this is not an OFF switch as the circuit will still consume battery power).
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The Junghans W707 in-house movement.
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No mainspring anywhere - all the power comes from the battery.
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The electronic module is held in place by a single screw.
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The huge balance wheel with two magnets and two counter-weights.
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Teardown of the escapement mechanism.
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A side view of the wheel train. As all the "drive" comes from the balance wheel, good lubrication is essential for good timekeeping here.
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Another view of the wheel train.
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The escape wheel engages directly with the balance wheel - a simple construction with a minimal number of parts.
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The parts before reassembly.
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Cleaned wheels - somewhat too much oil here...sorry.
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The movement back in action.
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Done and keeping time.
greetings noq2
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