when the switch the emitter-base junection is an opnd circut and heance the value of input or base curent is zero.
because that's how God intended the way of the world to be..
ONE low pass(RC) circuit gives 60 degrees phase shift
phase shift in integrator is 180 degrees and phase shift in differentiator is 0 degrees
Usually, the operating point of a transistor shift because of temperature induced gain or bias changes.
In the common emitter configuration, a class A amplifier, an increase in base voltage (the input) leads to an increase in base-emitter current which leads to a proportionately larger increase in base collector current. That pulls the collector towards the emitter, which decreases the collector voltage. Since the collector is the output, this configuration is an inverting amplifier.
In any transistor circuit , there is a phase shift. It takes a finite time for the controlling signal, usually on the base connection, to have an effect on the circuit and cause a change to the output. The shape of the signal remains but it is shifted in time (phase). The difference varies by configuration. It can be as much as180 degrees if the circuit is inverting the signal. The addition of passive components add to the shift.
A phase-shift oscillator using a PNP transistor consists of an RC network in the feedback path, a PNP transistor biased to operate in the active region, and a network of resistors and capacitors that provide the required phase shift for oscillation. The RC network introduces a 180-degree phase shift at the desired frequency, and the transistor provides the additional 180-degree phase shift needed for sustained oscillation. By properly selecting the values of resistors and capacitors, along with biasing the transistor correctly, a stable sinusoidal oscillation can be achieved.
because that's how God intended the way of the world to be..
No, in a common collector (CC) configuration, the input and output signals are in phase with each other. This is because the output voltage is taken from the collector terminal, where the collector current flows without any phase shift.
ONE low pass(RC) circuit gives 60 degrees phase shift
In an RC phase shift oscillator, oscillations are produced by the feedback network consisting of resistors and capacitors connected in a specific configuration to generate a 180-degree phase shift at the desired frequency. This phase shift, along with the inverting amplifier stage, satisfies the Barkhausen stability criterion for oscillation to occur. The loop gain of the circuit is unity and the phase shift of the feedback network is carefully controlled to ensure sustained oscillations at the desired frequency.
You mean "how does a phase shift oscillator introduce a phase shift of 180 degrees?" OK, we need two things for this type of oscillator: 1. A loop gain of more than 1.0, 2. A loop phase shift of zero degrees. The PSO achieves the gain using a valve, transistor, or op amp. It achieves the loop phase shift using (i) an inverting amplifier, equal to a phase shift of 180º, plus (ii) a network (usually resistor-capacitor) with a further phase shift of 180º. The loop shift is thus (180+180) = 360º/ zero degrees. It's easiest to use a three-part phase shift network, as the theoretically-possible two-part is difficult to make work, and the four-part is unneccessarily complex. The required phase shift of exactly 180º occurs at only one frequency, determined by the values of R and C.
The phase-shift oscillator gets its name from the phase-shift network used in its design, which introduces a phase shift in the feedback path of the circuit. This phase shift is necessary for maintaining oscillations in the circuit.
To achieve a maximum phase shift of 90 degrees in RC phase shift oscillators, you can use a combination of three RC stages in series, where each stage contributes 60 degrees of phase shift at the desired frequency. By carefully selecting the resistor and capacitor values to ensure that the total phase shift across the three stages reaches 180 degrees, you can then use a phase inverter, such as a transistor or an op-amp, to provide the additional 180 degrees needed for positive feedback. This setup ensures that the oscillator can sustain oscillations at the desired frequency.
phase shift in integrator is 180 degrees and phase shift in differentiator is 0 degrees
Change your keyboard configuration to US layout.
There is no phase shift.