Another type of sine-wave generator uses inductors and capacitors for its frequency-determining network. This type is known as the LC OSCILLATOR.
LC oscillators, which use tank circuits, are commonly used for the higher radio frequencies. They are not suitable for use as extremely low-frequency oscillators because the inductors and capacitors would be large in size, heavy, and costly to manufacture.
The difference between an RC and LC is that the frequency - determining device in the RC oscillator is not a tank circuit. LC can operate with A or C biasing, while RC can only operate with A.
A Colpitts oscillator is the electrical dual of a Hartley oscillator. In the Colpitts circuit, two capacitors and one inductor determine the frequency of oscillation. The feedback needed for oscillation is taken from a voltage divider made by the two capacitors, where in the Hartley circuit the feedback is taken from a voltage divider made by two inductors (or a tapped single inductor). (Note: the capacitor can be a variable device by using a varactor). Oscillation frequency The ideal frequency of oscillation for the circuit is given by the equation: where the series combination of C1 and C2 creates the effective capacitance of the LC tank. Real circuits will oscillate at a slightly lower frequency due to junction capacitances of the transistor and possibly other stray capacitances
At high frequencies for rc oscillators stray capacitances comes into act so q value reduses where for lc circutes q value is high
LC stands for Lucent Connectors
When an LC tank is excited at the resonant frequency, the energy across each will be equal (but not necessary equal at a given moment in time). If excited at a frequency other than the resonant frequency, the impedance of the inductor (wjL) and capacitor (1/wjC) will not be equal, therefore energy across each will be different.
RC phase shift oscillator is used to generate frequency in audio range and it is a fixed audio frequency oscillator where as wien bridge oscillator is a variable audio frequency oscillator for high frequency oscillations it is better to design wide band amplifier with LC network
depends on the oscillator and its purpose
The difference between an RC and LC is that the frequency - determining device in the RC oscillator is not a tank circuit. LC can operate with A or C biasing, while RC can only operate with A.
Because an RC oscillator is affected by stray capacitance in the active components in the circuit. HF oscillators use an LC tuned circuit to define the frequency.
A local oscillator is used in a superheterodyne radio circuit for example.The incoming radio frequency is mixed with an internal local oscillator circuit to generate a new intermediate frequency (IF) .The local oscillator usually runs at a frequency of 470kHz and is generated by an inductor and capacitor(LC oscillator)
A local oscillator is used in a superheterodyne radio circuit for example.The incoming radio frequency is mixed with an internal local oscillator circuit to generate a new intermediate frequency (IF) .The local oscillator usually runs at a frequency of 470kHz and is generated by an inductor and capacitor(LC oscillator)
Phase-shift oscillator Armstrong oscillator Cross-coupled LC oscillator RC oscillator
Phase-shift oscillator Armstrong oscillator Cross-coupled LC oscillator RC oscillator
don't use LC
1.CE amplifier circuit 2.LC oscillator circuit
DISADVANTAGES OF RC PHASE SHIFT OSCILLATOR.1. The output is small due to smaller feedback. 2. It is difficult for the Circuit to start oscillations.3. The Frequency stability is not so Good.4. It requires high Vcc. For large feedback.
difference between local oscillator and controlled oscillator