What Is A Crystal? And How To Test It
Crystal are use to keep the frequency of the clock from drifting. If the signal from this clock stops, or is weak, or the pulses begin to vary, the electronic equipments might show intermittent faults or might stop altogether. The microprocessor pins that hold the crystal are usually called OSC IN and OSC OUT as shown in Figure 1 and the frequency is marked on the crystal. Typical examples of crystal oscillator frequency are 3.58MHZ, 4MHZ, 8MHZ, 24MHZ etc. 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 LED, some other crystal checker uses a panel meter to indicate if the crystal is working or not. Jestine Yong is a electronic repairer and writer. For more information about electronic repair please visit his website at http://www.noahtec.com
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This problem can be solved by making better energy efficient air
conditioners and by making more energy
efficient computers. Many companies have taken a lot of interest
in subject. However, nothing substantial has been done primarily
because of the market requirements. The end users still want to host
their sites on the fastest processors which drives the market with the
latest processors. Going at this rate we would reach a time soon when
the energy required would be much higher than the energy available in
the market.
Intel, AMD, Transmeta and Via have all released processors which
consume very low power. A typical Pentium or AMD processor consumes
about 25 Watts of power, whereas these low powered processors take only
about 5 watts of power i.e. about 5 low powered processors would
consume as much power as a single main stream processor of today. These
low powered processors are also generally fan less processors which
means lower noise levels too. Intel has the centrino which has a lower
power consumption than the regular pentiums. Intel also has the arm
processors but those are RISC. Our prime focus would be AMD, Transmeta
and Via. They all have some very promising products.
One thing to be noted is that most of these low powered processors work
only at about 1.2GHz or lower. So they won't be as fast the pentium4s.
Which means one would have to host lesser sites per server. A good
recommendation would be upto a maximum of 600 sites on a
regular pentium 4 server. A low powered processor should comfortably
take about 200 sites. One advantage of these low powered processors is
that they have a very small form factor too. This means that one can
have more such servers in the same space that is typically allocated to
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for fan less operations. They are based on the mobile AMD Athlon
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For a long time Transmeta was known as the company where the
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the transmeta
efficeon
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important advantages, and manufacturers of all kinds of electronic
devices their first truly innovative new platform in over 25 years.
Thanks to Crusoe, mobile devices can be made smaller and lighter than
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manufacturer
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