ESA 9181

Description

It’s quite difficult to find out something about the history of old quartz movements, later than the Beta 21. Unfortunately, this also applies to the ESA 9181 shown here, the first ESA/ETA quartz movement, which was launched around 1973. It was technically very modern movement and thus often used.

The electronics part consists only of an integrated circuit of the type E7047, a rather voluminous 32768-Hertz quartz, a variable capacitor and an attached stepper motor. The electronic parts are all integrated in a plastic “plate” with screwed connections.

Easy to see, that this movement has got a very high degree of machine fabrication, but in case of an error, you cannot really fix parts of the electronics, you can only replace them in common. And as older the movement is, the difficulties of finding spare electronics parts increase.

The stepper motor of this movement is also a special one: On the lower side of the motor plate, there are four(!) embedded coils, which turn the stator almost silently. Modern quartz movement however use a simple Lavet stepper motor with only one coil and noisy stepper advencements.

The hacking feature is also pretty interessant: When the crown is pulled, a contact (to be seen at 8 o’clock position) is closed and not, as you would expect, opened. This is probably done to ensure, that the movement instantly starts when then crown is pushed in.

With 7 bearing jewels (four of them for the stepper motor), the movement is very well equipped and the reduced friction certainly leads to lower power consumption and also ensures the quiet working of the movement.

Since this movement uses lots of plastic parts, even on the date discs, it is not disassembled at all, since it’s a know fact, that plastic parts are becoming more and more fragile after time.

Technical data

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