Quartz crystal how does it work

Here they offer levels of performance that cannot be achieved by other forms of filter. Often several crystals may be used in one filter to provide the correct shape. There are two modes in which a crystal oscillator can operate and these can be seen from the equivalent circuit diagram. Quartz crystal resonators can operate in either mode, and in fact the difference between the parallel and series resonant frequencies is quite small.

Of the two modes, the parallel mode is more commonly used, but either may be used. Oscillator circuits for using the different modes are naturally different, as one oscillates when the crystal reaches its maximum impedance whilst the other operates when the crystal reaches its minimum impedance. The Q or quality factor is an important aspect of quartz crystal resonance.

Crystals offer very high levels of Q, sometimes in excess of Accordingly it is necessary to be able to calculate the level of Q to be able to determine other constraints and design considerations for the circuit in which it is to operate.

A straightforward equation is available to be able to calculate the value of Q for a given crystal. From this it can be seen that the series capacitance has a major effect on the Q. Lowering the series capacitance increases the Q in direct proportion for a given frequency. Quartz crystal resonators are a complex linkage between the electrical md mechanical domains. Although in theory it appears that theory operation appears quite straightforward, in practice many effects work together and they may link in unexpected manners.

It is not unknown for quartz crystal resonators to be excited by a different mode in a particular circuit and hence operate on an incorrect frequency. Understanding how quartz crystal resonators work can help identify these issues in the unlikely event they may occur.

Often adding a broadly resonant circuit to the oscillator to ensure that it can only operate in the required mode suffices in this instance. Circuit symbol for a quartz crystal resonator, xtal Piezo-electric effect When looking at how a quartz crystal works, it is first necessary to understand the basics of the piezo-electric effect. It is an effect that occurs in a number of materials, both naturally occurring and synthetic. How does a quartz crystal resonator work: the basics For the operation of a quartz crystal it is found that the piezo-electric effect converts the electrical impulses to mechanical stress which is subject to the very high Q mechanical resonances of the crystal, and this is in turn linked back into the electrical circuit.

When looking at how a quartz crystal resonator works, it can be seen that there are three main ways in which a crystal can vibrate: Longitudinal mode: In the longitudinal mode the crystal extends and shortens. Posted by Nicholas Crusie on September 08, To understand quartz watches, we need to first understand the standard ways in which watches are powered.

There are three main types of movements, or energy types, used in watches on the market today:. Mechanical watches are the kingpin of the watch world. Mechanical watches have been around since the beginning of watches.

In over a century of modifications and technological advancements, the most significant difference in a mechanical watch besides the individual watch design themselves is that mechanical watches now use a built-in crown, instead of a tiny key to wind the inner mainspring.

Mechanical watches are hand-wound timepieces that use a complex movement composed of hundreds of small parts that work together in harmony to make a mechanical watch tick. While automatic movements are technically an older technology than quartz movements, they are still among the most common movements in watches because they exude a different degree of quality, craftsmanship, and complexity.

Instead of batteries, they run off of the energy from a wound spring. This mainspring stores energy and distributes it through interconnected gears and other springs controlling the energy supply to power the watch.

For those in the pursuit of ultimate time-keeping precision, a quartz watch will be a clear choice. Once upon a time, quartz was a state-of-the-art technology that almost overturned the entire watchmaking industry. Heading off what is considered the Quartz Revolution or some Quartz Crisis depending on your feelings , quartz soon showed that the most effective and accurate way to tell time was not through a complex network of gears, but with a simple crystal, battery and tiny motors.

Utilizing this new time-keeping technology was considered unforgivable to some, as it disrupted the status quo of the watch winding world. Let us not forget that a quartz watch, except for the occasional change of batteries, needs far less service than its mechanical alternative. Also, unlike mechanical watches, gravity does not affect the inner workings at all, so a quartz watch tells the time just as well when you are deep under the ocean in a submarine as it does when you are climbing the highest mountain.

Forget that quartz is more affordable than mechanical watches. All clocks need an oscillating, regulating element to keep the time accurate. In mechanical clocks and watches, it exists in the form of a balance spring and balance wheel.

For a quartz watch, however, there is a tiny quartz crystal cut in the shape of a tuning fork. Quartz naturally vibrates at an exact frequency and contains piezoelectric properties, which means that when it is pressurized, it produces a small volt of electricity. If you have an account, sign in with your email address.

Sign In. Forgot Your Password? Sign in with Apple Continue with Apple. Personal Information First Name. Last Name. Sign Up for Newsletter. Password Password Strength: No Password. Confirm Password.