quartz watch science knowledge
The world's first quartz watch was made in Switzerland in July 1967.
In 1969, Japan Seiko (Seiko), launched the world's first mass-produced quartz watch, named "Quartz Astron"
quartz material characteristics:
When a quartz crystal is affected by battery power, it vibrates regularly. The quartz crystal vibrates up to 32768 times per second.
working principle of quartz watch:
All quartz watches are equipped with a battery. It provides energy for an IC integrated circuit and a quartz oscillator, energizes the quartz crystal in the quartz watch, and the quartz vibrates correctly at a frequency of 32768Hz. The quartz oscillator is vibrated by the oscillation circuit and the quartz oscillator to form an oscillation circuit source. The formation of alternating bi-directional pulse signal, so as to drive the stepper motor for intermittent rotation.
The rotor in the stepping motor rotates 180 ° each time, and is transmitted to the second wheel through the transmission gear train to rotate intermittently at an angle of 6 ° per second, so that the watch hands can accurately display the time.
The IC integrated circuit is the "brain" of the quartz watch ". It controls the vibration of the quartz resonator and acts as a frequency divider. The 32768 vibrations are split in half 15 times, (2 ^ 15=32768) to achieve one pulse per second. (So the second hand of the quartz watch goes one second)
Quartz watch is affected by temperature
Quartz crystal oscillator watch is quartz crystal watch, with temperature sensitivity. Its accuracy varies with temperature. The picture below shows the effect of temperature on the oscillator in a quartz watch.
Click to view the original
The angle of the quartz crystal in the watch is cut at 25°C with a zero temperature coefficient. This has been shown to have the highest possible accuracy when the watch is on and off the wrist at the usual durations and temperatures. In fact, this also tells you that in the case of extreme temperatures, quartz crystal watches will also appear error
What is the role of the pits on the stator in the stepper motor?
The two symmetrical semicircular pits inside the stator are used to change the magnetic resistance in the air gap between the stator and the rotor to control the positioning position and rotation direction of the rotor. Damage to the stator may result in a change in the direction of rotation of the rotor, resulting in a reversal of the second hand.