The crystal behaves like an inductor in that it bends mechanically when a voltage is applied. When the power is cut off, the stress of the bend is released to generate electricity, which is then stored after being fed into a capacitor. When the bending returns to normal, the electric energy in the capacitor will act on the crystal oscillator, and the circuit will capture the release time, and positive feedback it, with the same polarity and the capacitor together into the crystal oscillator, strengthen its bending, repeat the process just now. That is, a similar LC circuit is composed of capacitance and crystal oscillator.

500kw load bank
 

Crystal oscillator needs external capacitance, but also to make the equivalent capacitance at both ends of the crystal oscillator (distributed capacitance between the circuit) is equal to the load capacitance, load is crystal vibration capacitance, at this time the role of capacitance is very obvious, charging, crystal vibration. The load capacitance is very important to determine whether the crystal oscillator can work properly in the product.

If in the purchase of crystal, it is best to put the required load capacitance and other important parameters, but also with the purchase instructions; So the procurement in the crystal selection process, will reduce a lot of selection detours. If the load of the crystal oscillator can not be confirmed, the capacitor is difficult to match, and the starting capacitor can not be charged and discharged, and the crystal oscillator can not be started; When the distributed capacitance is equal to the crystal capacitance, the crystal oscillator can be made to emit resonance frequency. Capacitance size can affect the stability and phase of crystal oscillator frequency, the smaller the price will be higher. So the load also determines the price of the crystal itself.