What is a crystal ? And how to test it.

By: Jestine Yong

Testing Crystal
Crystals are quite fragile components because of their construction. Unlike a resistor or capacitor, if you drop one on the ground from a decent height, its 50-50 bet whether it will work again. Testing the crystal is not a breeze either. You cannot just take out your trusty multimeter and plug the crystal in it. In fact, there are three right ways to test a crystal: -

(a) Using Oscilloscope
A crystal produces a sine wave when excited. It is appropriate then, to see a waveform representative of a sine wave on the clock pins.

If the clock is not functioning properly, replace the crystal. In most cases this should solve the problem since microprocessors are usually very reliable. Check the crystal with power on.

(b) Frequency Counter
Frequency Counter can be use to check the frequency of the crystal. The reading must be taken when the equipment power is switch “on". Place the probe of frequency counter to the crystal pin and read the measurement. Be sure that your frequency counter meter has the range that is higher than the crystal frequency you are measuring.

(c) Crystal Checker
With this method, usually the crystal is placed in the feedback network of a transistor oscillator. If it oscillates and the LED is lighten up, this mean that the crystal is working. If the crystal doesn’t work, the LED stays off. Instead of using LEDComputer Technology Articles, some other crystal checker uses a panel meter to indicate if the crystal is working or not.

Technology
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 
 • 

» More on Technology
 



Share this article :
Click to see more related articles