ELi5: Which technology do digital watches use to measure time?

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There are multiple methods to measure time. In the past, we had unreliable time measuring tools like sundials and hourglasses. Then Christiaan Huygens using the concept of SHM invented the pendulum clock which was the first precise enough time measuring device. Eventually Pendulum was replaced by Quartz Crystals which are used in Analogue clocks and watches. I want to know which method do digital clocks and watches use? It is Quartz crystals or something other? Is that other more precise than Quartz crystal?

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15 Answers

Anonymous 0 Comments

Digital watches use quartz crystals. The crystal oscillates at 32768 cycles per second. This number was chosen because it can be divided by two fifteen times to get one pulse per second. The crystal is shaped like a tuning fork. The crystal frequency is very accurate. It can be adjusted to be accurate to one second per week, with a device called a variable capacitor.

Anonymous 0 Comments

Digital watches use quartz crystals. The crystal oscillates at 32768 cycles per second. This number was chosen because it can be divided by two fifteen times to get one pulse per second. The crystal is shaped like a tuning fork. The crystal frequency is very accurate. It can be adjusted to be accurate to one second per week, with a device called a variable capacitor.

Anonymous 0 Comments

Still quartz crystals, their sort of accuracy is far more than adequate for daily use.

Unless you have a watch that gets periodic (usually daily) updates from various atomic time signals.

Anonymous 0 Comments

Still quartz crystals, their sort of accuracy is far more than adequate for daily use.

Unless you have a watch that gets periodic (usually daily) updates from various atomic time signals.

Anonymous 0 Comments

Still quartz crystals, their sort of accuracy is far more than adequate for daily use.

Unless you have a watch that gets periodic (usually daily) updates from various atomic time signals.

Anonymous 0 Comments

Digital watches use quartz crystals. The crystal oscillates at 32768 cycles per second. This number was chosen because it can be divided by two fifteen times to get one pulse per second. The crystal is shaped like a tuning fork. The crystal frequency is very accurate. It can be adjusted to be accurate to one second per week, with a device called a variable capacitor.

Anonymous 0 Comments

1. Plain old quartz crystals are still widely used.
2. Temperature calibrated quartz crystals. These are chips that has a temperature sensor and a correction table in internal memory for each temperature value. They are calibrated at the factory. They are an order of magnitude more accurate than plain quartz crystals.
3. Power grid frequency. In Western countries power grid frequency is adjusted to be within 10-15 seconds of the true time. The frequency is occasionally increased or decreased when needed.
4. Radio signal. In many areas accurate time marks are broadcast digitally. A chip that decodes the signal costs $1-$2.
5. A time server over Internet.
6. A GPS receiver is pretty affordable these days.

Anonymous 0 Comments

1. Plain old quartz crystals are still widely used.
2. Temperature calibrated quartz crystals. These are chips that has a temperature sensor and a correction table in internal memory for each temperature value. They are calibrated at the factory. They are an order of magnitude more accurate than plain quartz crystals.
3. Power grid frequency. In Western countries power grid frequency is adjusted to be within 10-15 seconds of the true time. The frequency is occasionally increased or decreased when needed.
4. Radio signal. In many areas accurate time marks are broadcast digitally. A chip that decodes the signal costs $1-$2.
5. A time server over Internet.
6. A GPS receiver is pretty affordable these days.

Anonymous 0 Comments

1. Plain old quartz crystals are still widely used.
2. Temperature calibrated quartz crystals. These are chips that has a temperature sensor and a correction table in internal memory for each temperature value. They are calibrated at the factory. They are an order of magnitude more accurate than plain quartz crystals.
3. Power grid frequency. In Western countries power grid frequency is adjusted to be within 10-15 seconds of the true time. The frequency is occasionally increased or decreased when needed.
4. Radio signal. In many areas accurate time marks are broadcast digitally. A chip that decodes the signal costs $1-$2.
5. A time server over Internet.
6. A GPS receiver is pretty affordable these days.

Anonymous 0 Comments

If you just mean a watch with a digital display (as opposed to an Apple watch or something like that) They still use quartz crystals. Quartz crystal watches are very accurate, easy to manufacture, and affordable. The “digital” part of digital watch only means that the time is *displayed* on a digital screen. The actual timekeeping mechanism is the same.*

*Again, unless you have something like an Apple watch or other smart watch that connects to the internet or data network.