In crystal oscillator, crystal is used in place of tank circuit. certain substances; For example, the properties of crystals are found in quartz, Rochelle salt etc. Crystal oscillators have the property of frequency stability. The vibrational frequency of a crystal is inversely proportional to its thickness, i.e. (14). Quartz crystals are used to make oscillators of frequencies from 50 kHz to 50 MHz, which have a frequency stability of 0.02%.
Piezo electric effect
The working operation of crystal oscillator is based on quartz crystal effect, crystal arrangement and its ac. The equivalent circuit is shown. A special property of a quartz crystal is that if mechanical stress is applied to its surfaces, a potential difference is produced between opposite faces, or if a voltage is applied to one face of the crystal. Then a mechanical force is generated on its other face, which causes expansion or contraction in the crystal. This special property of the crystal is called the piezoelectric effect of the crystal.
Working Method
The crystal oscillator circuit is shown. The oscillation frequency of this circuit is determined by the crystal connected to the base circuit. In the first half-cycle, the crystal collects the electrical energy in the form of mechanical energy and in the second half-cycle it is released as electrical energy and gives it to the circuit. The RFC added to the base circuit helps in stabilizing the base bias. The output of this circuit is obtained from the transformer’s coil L, ‘
Whereas the coil L provides the feedback voltage to the base circuit. Capacitor C2 acts as a blocking capacitor.
Piezoelectric Effect को पीजो-विद्युत प्रभाव या दाब वैद्युतकी प्रभाव भी कहते हैं | पीजो-विद्युत प्रभाव वैद्युत से संबंधित ऐसी घटना है जिसमें इलैक्ट्रिक बल लगता है जिसकी जांच करने के लिए इलैक्ट्रिक प्रभाव के परिणाम और शुद्धिकरण की जांच की जाती है |
कहाँ देखें Piezoelectric Effect
पीजो-विद्युत प्रभाव को लैब में जाकर प्रैक्टिकल के रूप में देखा जा सकता है | वैद्युतकी प्रभाव को इलैक्ट्रॉन की शुद्धता के साथ साथ देखी जा सकती है | Electric क्षेत्र में पीजो-विद्युत प्रभाव को उपयोग में लाया जाता है |