In common emitter amplifier circuit, input and output voltage are out of phase. When input voltage is increased then ib is increased, ic also increases so voltage drop across Rc is increased. However, increase in voltage across RC is in opposite sense. So, the phase difference between the input and the output voltages is 180 degrees.
Inversion. For a sinewave input this looks like 180 degree phase shift.
A: Because it is a voltage amplifier the current will inversely reflect the voltage across a resistor
This is a particular transistor amplifier configuration. In general, the input signal is applied to the base, the collector is connected to a supply voltage, and the output is taken between the emitter and power supply common. One of the characteristics of the emitter follower is the output voltage "follows" the input, but the output is reduced by the Vbe voltage (the voltage drop between base and emitter, approximately 0.7 V for a silicon bipolar transistor).
The emitter bypass capacitor, in a typical common emitter configuration, increases gain as a function of frequency, making a high pass filter. Removing the capacitor will remove the gain component due to frequency, and the amplifier will degrade to its DC characteristics.
UJT means Uni Junction transistor terminals are Emitter,Base1 and Base2.UJT is also called double base diode.UJT operates when the emitter is forward biased.voltage is applied between base1 and base2.If an external voltage is applied at terminal E,no current will flow in to the emitter as long as this applied voltage is less than emitter voltage.When this applied voltage exceeds emitter voltage,current will flow into the emitter and holes get injected from emitter to base1 and are repelled by base2.This results in increase in the region between the junction and the base 1.The increase in conductivity results drop in emitter voltage and increased forward bias of the junction.so emitter current also increases.Then it exhibits a negative resistance.
the common emitter configuration is most widely used in amplifer circuits because of its high voltage,current & power gain.the common emitter configuration is most widely used in amplifer circuits because of its high voltage,current & power gain.
I think you mean a common emitter amplifier, which is an amplifier of voltage. Emitter-follower or common collector amplifiers are used to match impedances, or to amplify power or current. The emitter-follower is a type of common emitter circuit that has a resistor between the emitter and ground. The output signal is taken from the point between the emitter and its resistor.
We bias the common emitter amplifier to have a collector-emitter voltage of one half of Vcc in order to set the operating point halfway between the two extremes.
A: Because it is a voltage amplifier the current will inversely reflect the voltage across a resistor
This is a particular transistor amplifier configuration. In general, the input signal is applied to the base, the collector is connected to a supply voltage, and the output is taken between the emitter and power supply common. One of the characteristics of the emitter follower is the output voltage "follows" the input, but the output is reduced by the Vbe voltage (the voltage drop between base and emitter, approximately 0.7 V for a silicon bipolar transistor).
The question does not quite make sense. It sounds like you are asking why does changing the emitter resistor in a class C common collector amplifier not affect the output voltage? If so, the answer is that the common collector is an emitter follower, meaning that the emitter will follow the base, less the base-emitter junction voltage, within the limits of hFe. The resistor is simply there to ensure output biasing when the base voltage goes low.
In the common emitter amplifier, an increase of base-emitter current causes a larger increase of collector emitter current. This means that, as the base voltage increases, the collector voltage decreases. This is a 180 degree phase shift.
it makes sound :) trollolololol
The output of a common emitter stage is inverted, it is not out of phase.
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.
Disadvantages of CE amplifier:1. It has a high output resistance.2. It responds poorly to high frequencies.3. It has high thermal instabilities.4. It's voltage gain is very unstable.
Current gain. At the cost of no voltage gain.
A diode is not an amplifier. It is a rectifier with asymmetrical voltage breakdown voltages. Usually the forward voltage is around 0.6V to 0.7V (silicon), and the reverse voltage is smaller than breakdown voltage, which is much higher. A transistor can be used as an amplifier, by taking into account the fact that the voltage breakdown curves vary, usually collector-emitter, as a function of some other current, usually base-emitter, but this depends on the class of the amplifier and whether or not the transistor is driven into saturation.