[adrian_b]

While most quartz watches use cheaper stepping motors, there are also quartz watches which use synchronous motors, so the hands have a perfectly uniform and noiseless rotation movement.

I had some big wall clocks of this kind, and my father had such wrist watches.

The energy consumption of synchronous motors is lower, because they only have to overcome the friction forces, without having to also accelerate the mass of the hands.

[dadoge]

I have a clock that is smooth. Bigger batteries help with that, compared to a small wristwatch battery.

A quartz wristwatch with a smooth seconds hand? How long does the battery last?

[adrian_b]

I am not sure, because that was some years ago, when my father, who used the watch, was still alive, but in any case the battery lasted at least a year.

[numpad0]

Yeah, not that I perceive it to be an assumption that is entirely illogical, but why is smooth movement supposed to consume more power? I can understand that jumping less often conserves power but the power hierarchy should be more ticks > less ticks > no ticks, if we ignore potential increased frictions at lower angular velocity as well as challenges of resisting disturbances.

[CydeWeys]

Ticking is achieved with stepper motors. Whatever motor is required to smoothly rotate uses more power.

[adrian_b]

At large sizes, synchronous motors are much more efficient than stepper motors, so they use much less power.

At small sizes, the synchronous motors must use permanent magnets, which increase their cost and they have windings that are more difficult to make and the difficulty increases with the smallness of the motor.

The electronic drive of a synchronous motor is more expensive, because it must generate sinusoidal currents, not rectangular currents.

At small sizes, a synchronous motor may have a lower torque than a stepper motor , so it might need extra gears, which would increase the cost.

As long as it is still cost-effective to manufacture a synchronous motor, it will always have a better efficiency and a lower power consumption than a stepper motor. The reason why stepper motors are preferred is that at very small sizes they can be much cheaper, especially when including the cost of all associated electronic and mechanical components.

[numpad0]

Synchronous motors are bit like stepless stepper motors.