3 ms·

How can we debate whether the spring drive's fully mechanical or not? It's got a quartz oscillator and an integrated circuit.

craigsmansion 9y ago
Well, for one, the escapement doesn't depend on the quartz crystal for timekeeping, but on magnetic induction. Spring drive would theoretically work without the quartz components. Seeing how they would generate an electrical current because of the principle, they build a tiny generator to drive a circuit that adjusts the escapement, but doesn't run it. Also, Spring Drive depends on a fully mechanical wheel train and barrel spring to function; it could not be made to work with a battery. So what exactly constitutes mechanical and what does quartz here? Is it the wheel train? Does electro-mechanical count as mechanical? Is the mere presence of a quartz crystal in a secondary circuit enough to call it a quartz? I found it easier to see it a as a new different system for timekeeping instead of trying to place it on an arbitrary scale between "fully mechanical" and "quartz."
- SamReidHughes 9y ago
  > Well, for one, the escapement doesn't depend on the quartz crystal for timekeeping No, it uses the quartz crystal for timekeeping. It keeps time like any other digital watch, only it outputs that time by controlling the rotor's speed, and gets its power from the rotor. It could keep time mechanically instead and still use electronics to maintain the rotor's speed. But in fact it uses a quartz crystal.
- twic 9y ago
  How does the spring drive actually work? What is the mechanism which keeps it moving at a consistent speed? A quick google only turned up rather vague descriptions.
  - craigsmansion 9y ago
    At the heart of every mechanical watch lies a coiled spring. Within that spring energy is stored that wants to be released. This energy is released through the wheel train, which is a set of cogs with reductions (some of them attached to the hands). Left to its own device this system would just spin as quickly as possible until the spring is unwound. To prevent this, somewhere in the train there is something called a lever escapement. Simple put, this puts a stick in a cog at regular intervals to prevent it from spinning and unwinding freely. This stick is timed by a weight that spins from left to right. This stick literally is what makes watches tick, since that's where the ticking sound comes from. Spring Drive doesn't poke a stick into a wheel to prevent the system from freely unwinding. What it does do is add magnets to the wheel and stationary coils around it. The wheel can't spin freely since it has to overcome the magnetic induction as the magnets pass the coils. That's the reason SpringDrive doesn't tick and the hands glide instead of stopping and starting. If it's still unclear, try looking up escapement levers first. There should be a lot of clear animated explanations online.
    - twic 9y ago
      I understand (roughly!) the basic idea of a watch mechanism, and how mechanical escapements work. What i don't understand is exactly how the spring drive keeps the wheel moving at a constant speed. I appreciate that this involves magnets, and eddy currents induced by those magnets, but that's a description, not an explanation. What is the mechanism, physically and mathemetically, that keeps the speed constant?
      - SamReidHughes 9y ago
        Inertia. The torque applied by electromagnetic force on the rotor plus that of friction and air resistance equals the torque applied (indirectly through a gear train) by the mainspring. The net torque is zero and the rotor keeps going at the same rate of rotation. The integrated circuit counts how many times the rotor has spun compared to how many quartz crystal oscillations have happened and adjusts the electromagnetic force somehow. My guess is by increasing/decreasing the power passing through some resistor (creating heat).
      - 9y ago

craigsmansion 9y ago

Well, for one, the escapement doesn't depend on the quartz crystal for timekeeping, but on magnetic induction. Spring drive would theoretically work without the quartz components. Seeing how they would generate an electrical current because of the principle, they build a tiny generator to drive a circuit that adjusts the escapement, but doesn't run it. Also, Spring Drive depends on a fully mechanical wheel train and barrel spring to function; it could not be made to work with a battery. So what exactly constitutes mechanical and what does quartz here? Is it the wheel train? Does electro-mechanical count as mechanical? Is the mere presence of a quartz crystal in a secondary circuit enough to call it a quartz? I found it easier to see it a as a new different system for timekeeping instead of trying to place it on an arbitrary scale between "fully mechanical" and "quartz."

SamReidHughes 9y ago
> Well, for one, the escapement doesn't depend on the quartz crystal for timekeeping No, it uses the quartz crystal for timekeeping. It keeps time like any other digital watch, only it outputs that time by controlling the rotor's speed, and gets its power from the rotor. It could keep time mechanically instead and still use electronics to maintain the rotor's speed. But in fact it uses a quartz crystal.
twic 9y ago
How does the spring drive actually work? What is the mechanism which keeps it moving at a consistent speed? A quick google only turned up rather vague descriptions.
- craigsmansion 9y ago
  At the heart of every mechanical watch lies a coiled spring. Within that spring energy is stored that wants to be released. This energy is released through the wheel train, which is a set of cogs with reductions (some of them attached to the hands). Left to its own device this system would just spin as quickly as possible until the spring is unwound. To prevent this, somewhere in the train there is something called a lever escapement. Simple put, this puts a stick in a cog at regular intervals to prevent it from spinning and unwinding freely. This stick is timed by a weight that spins from left to right. This stick literally is what makes watches tick, since that's where the ticking sound comes from. Spring Drive doesn't poke a stick into a wheel to prevent the system from freely unwinding. What it does do is add magnets to the wheel and stationary coils around it. The wheel can't spin freely since it has to overcome the magnetic induction as the magnets pass the coils. That's the reason SpringDrive doesn't tick and the hands glide instead of stopping and starting. If it's still unclear, try looking up escapement levers first. There should be a lot of clear animated explanations online.
  - twic 9y ago
    I understand (roughly!) the basic idea of a watch mechanism, and how mechanical escapements work. What i don't understand is exactly how the spring drive keeps the wheel moving at a constant speed. I appreciate that this involves magnets, and eddy currents induced by those magnets, but that's a description, not an explanation. What is the mechanism, physically and mathemetically, that keeps the speed constant?
    - SamReidHughes 9y ago
      Inertia. The torque applied by electromagnetic force on the rotor plus that of friction and air resistance equals the torque applied (indirectly through a gear train) by the mainspring. The net torque is zero and the rotor keeps going at the same rate of rotation. The integrated circuit counts how many times the rotor has spun compared to how many quartz crystal oscillations have happened and adjusts the electromagnetic force somehow. My guess is by increasing/decreasing the power passing through some resistor (creating heat).
    - 9y ago