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There are many different types of oscillator circuits, the majority of which use positive feedback.
Marielle Crist
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What are the three conditions for sine wave oscillations to be generated?
To start the oscillation with the constant amplitude, positive feedback is not the only sufficient condition. Oscillator circuit must satisfy the following two conditions known as Barkhausen conditions:1. The first condition is that the magnitude of the loop gain (Aβ) must be unity. This means the product of gain of amplifier 'A' and the gain of feedback network 'β' has to be unity.2. The second condition is that the phase shift around the loop must be 360° or 0°. This means, the phase shift through the amplifier and feedback network has to be 360° or 0°.In practice, to obtain the sustained oscillations at desired frequency of oscillations, oscillator circuit must satisfy some of the basic requirements such as,Circuit must have positive feedbackWhen positive feedback is used in the circuit, the overall circuit gain is given by,
What does it means a quartz watch?
It is a watch that uses an oscillator based on a quartz crystal to electronically keep time. Older watches used gears and an escape mechanism to govern the speed. In a quartz watch, a precision cut piece of quartz is used in part of a circuit to generate a specific frequency. A quartz clock works similarly, but the quartz oscillator is used to control the speed of a motor.
What type energy flows in a circuit?
Quite often, the word "circuit" is used for an electrical circuit. In that case, the energy is electrical energy.
What type of energy flows in a circuit?
Quite often, the word "circuit" is used for an electrical circuit. In that case, the energy is electrical energy.
Why you use crystal oscillator in 8085 microprocessor?
The oscillator provides the basic clock of a microcontroller to be able to execute the instructions in a stable, periodic way. It is often used for other peripherals too, like timer, UART, etc. as frequency base, usually divided by a clock divider for integer factors, or by PLL for rational factors. If the timing accuracy of these functions is not important, a simple RC oscillator can be used. Many microcontrollers have it internally. Accuracy is in 1...10% range. For better accuracy and temperature stability, a resonator can be used. For applications where timing is critical, a crystal can be used. Most micros have built-in oscillator, so only a crystal and two caps are needed. For those which have no built-in oscillator, external crystal oscillator module may be used. There are OCXO and TCXO modules available for very high stability needs.
What type of feedback is used in the phase shift oscillator circuit?
Positive feedback
What type of oscillator used in handwatches?
a crystal 32.768kHz oscillator.
What is blocking oscillator?
The oscillator which is blocked by using transformer is called a blocking oscillator. Generally, the primary is given to the base and secondary is given to the collector of the transistor used in the oscillator circuit.
Why crystal oscillator used for microcontrollers?
Oscillators are connected externally with the microcontroller to provide high frequency signal to the oscillator circuit in the microcontroller. The oscillator circuit provides the clock signal to the micro controller. Usually "PIEZO CRYSTAL OSCILLATORS" are used in micro controllers.
Why is positive feedback used in oscillators?
Positive feedback is used in oscillators to keep them running or oscillating. An oscillator is basically an amplifier which has a feedback path from the output back to the input. This permits a portion of the output signal to get back to the input to "keep things going" in stage - to keep things oscillating. The feedback must be positive so that it will "contribute" to the stage being able to keep oscillating. If the feedback was negative, it would serve to damp the oscillation and to "kill" the oscillator.
What is the purpose of an oscillator crystal?
"A circuit within a computer that creates a series of pulses that pace the computer's electronic system. The oscillator clock synchronizes, paces and coordinates the operations of the computer's circuit." -- webopedia
What is a local oscillation?
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)
What is local oscilator?
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)
What is the circuit diagram of magnetostriction oscillator?
magneto striction oscillator is used to produce ultrasonic waves by using the the principle of inverse piezo electric effect
Where a colpitts oscillator is used?
the Colpitts oscillator , named after the inventor of the circuit , is characterised by the use of Two Capacitors in series which are then connected in parallel across the inductor of the resonant circuit for obtaining the required frequency. The junction of the two capacitors is used for the positive feedback used for generating the oscillations. This circuit is used for High frequency oscillators , mainly due to ease of obtaining required ratio of the two capacitor values as per the circuit design. Also the two capacitors in series reduces their total equivalent value , which is not a problem as in HF circuits as the values and size is comparatively low. For information , a corresponding Low frequency circuit is called a Hartley oscillator , also named after its inventor. This uses a tapped inductor & one capacitor for the resonant circuit, since it is more easier to fabricate large value tapped inductors , than to use two bulky ( since the value of capacitors in series is reduced ) capacitors necessary for the equivalent Colpitts oscillator.
Why rf choke is used in collpitts oscillator?
To isolate the bias circuitry of the transistor from the feedback network with RF currents.
What are the three conditions for sine wave oscillations to be generated?
To start the oscillation with the constant amplitude, positive feedback is not the only sufficient condition. Oscillator circuit must satisfy the following two conditions known as Barkhausen conditions:1. The first condition is that the magnitude of the loop gain (Aβ) must be unity. This means the product of gain of amplifier 'A' and the gain of feedback network 'β' has to be unity.2. The second condition is that the phase shift around the loop must be 360° or 0°. This means, the phase shift through the amplifier and feedback network has to be 360° or 0°.In practice, to obtain the sustained oscillations at desired frequency of oscillations, oscillator circuit must satisfy some of the basic requirements such as,Circuit must have positive feedbackWhen positive feedback is used in the circuit, the overall circuit gain is given by,
