Oscillators Objectives Part 04
61 . Wein Bridge Oscillator for generating a 1 kHz
62 . LC oscillators can be used to produce frequencies as high as 500MHz
63 . An oscillator using LC tuned circuit ha.sLe 58.6 PH and C = 300 pF. The oscillations will be nearly 1200kHz
64 . Colpitts scillator will be ferred for generating 1 MHz
65 . RC network shown in Fig. 23 is used inalow frequency oscillator circuit. The frequency of oscillations will 15.9kHz
66 . for producing a frequency of 1.6 kHz, the values of capacitors should be 995pF
67 . Oscillators are widely used in Radio, television broadcasting.
68 . A multivibrator produces Square Waves.
69 . When positive feedback amplifiers are used as Oscillator, the condition is known as AB=1 Barkhasen criterion of oscillation.
70 . The requirement of an oscillator using positive amplifier as an oscillator, is that here must be positive feedback, initially the value of loop gain Åß must greater than unity,
after the desired level is reiEhed the loop gain AP must decrease to unity.
71 . The main advantage of using crystal oscillators is constant frequency of oscillations.
72 . for oscillation to start., the loop gain AB of the Oscillator must be more than One
73 . A tuned circuit used in Colpitts oscillator is shown the frequency of oscillators will be 100MHz
74 . sinusoidal oscillator is preferred for microwave frequencies is Negative Resistance Oscillator.