There is no problem with quartz crystal selection timing element.
Quartz crystals may be several thousand times more time-honored than tuning forks, and quartz crystals have been around for many years.
Only the type and frequency of the Crystal need to be selected.
The difficulty is to choose an integrated circuit technology that can work at low enough power.
Quartz crystals have been in regular use for many years, providing accurate frequencies for all radio transmitters, radio receivers and computers.
Their accuracy comes from a series of amazing coincidences: Quartz--
Silica like most sand-
Not affected by most solvents, the crystal state of Baidu in Fahrenheit is maintained.
The characteristic of making it an electronic miracle is that when compressed or bent, it generates a charge or voltage on its surface.
This is a fairly common phenomenon called piezoelectric effect.
Similarly, Quartz will bend slightly or change its shape if applied voltage.
If a bell is formed by grinding quartz crystals, it will ring for a few minutes after being tapped.
There is little energy loss in the material. A quartz bell --
If formed in the correct direction of the crystal axis--
There will be an oscillation voltage on the surface, and the oscillation rate is not affected by temperature.
If the surface voltage on the crystal is picked up with an electroplating electrode and amplified with a transistor or integrated circuit, it can be re-
Used to keep the bell ringing.
A quartz clock can be made, but it is not the best shape because too much energy is coupled with air.
The best shape is straight bars or discs.
The advantage of the bar is that as long as the aspect ratio remains the same, the same frequency can be maintained.
The quartz bar can be small and oscillate at a relatively low frequency-32 kilohertz (KHz)
The watch is usually chosen not only for size, but also because the circuit from crystal frequency to several pulses per second of the display requires more power at a higher frequency.
Power supply was a big problem for early watches, Switzerland spent millions of dollars trying to bring up integration
Circuit technology for generating more stable disk-like crystals from 1 MHz to 2 MHz.
Modern quartz watches are now low
Frequency bar or tuning-fork-shaped crystal.
Typically, these crystals are made from a sheet of quartz plated like an integrated circuit and are formed by chemical corrosion.
The main difference between good and different time retention is the initial frequency accuracy and the cutting angle accuracy of the quartz sheet relative to the crystal axis.
The amount of contamination that allows to reach the surface of the crystal inside the watch through encapsulation also affects accuracy.
The electronic device of the watch will initially amplify the noise at the crystal frequency.
This is formed or regenerated as an oscillation--
It started the Crystal Bell.
The output of the watch crystal oscillator is then converted to a pulse suitable for the digital circuit.
These reduce the frequency of the crystal and then convert it to the correct format displayed. (
For a detailed discussion of the voltage divider and the display driver, see how the digital clock works. )
Alternatively, in a quartz watch with a pointer, the splitter generates-
Drive the second pulse of a small motor connected to a standard gear to drive the hand.
For more information, please see the link below.
Douglas Dwyer is the founder of frequency Precision Co. , Ltd. , providing consulting and design services to the world
Extensive electronics industry.
He has been involved in frequency control since the medium term
1960 seconds and published an article on crystal oscillator, temperature
Oven-compensation crystal oscillator
Control crystal oscillator, Surface acoustic oscillator and industrial quartz crystal manufacturing technology.
Since he participated in the design of the quartz watch, the history of the watch has always been his interest.