because, it is work on negative resistance region
A relaxation oscillator is the one which consists of an RC network,in which the capacitor is charged from a DC fixed voltage source, through a resistor. see the link below. the capacitor is charged through the resistor Re. That is why a ujt can be called a relaxation oscillator.
It is sawtooth waweform genrator
The main application of the U.J.T is it is used as relaxation oscillator
The simplest application of a UJT is as a relaxation oscillator, which is defined as one in which a capacitor is charged gradually and then discharged rapidly.
It can be used as a Sawtooth wave generator
why ujt used as amplifier
in this circuit a capactor charges until the stand off voltage of the ujt is reached and the ujt shuts off causing the capactor to discharge. The time is controlled by the RC time constant of the RC circuit. So what really happens in the ujt conducts and allow the capacator to charge until the ujt shuts off and then the capactor discharges the cycle repaeats itself over and over because as the capactor discharges the ujt will again turn on allowing the capacator to charge. It is an saw tooth waveform generator.
A nonlinear or relaxation oscillator produces a non-sinusoidal output, such as a square, sawtooth or triangle wave. And RC oscillator produces sinusoidal output.
The operation of the circuit is as follows: C1 charges through R1 until the voltage across it reaches the peak point. The emitter current then rises rapidly, discharging C1 through the base 1 region and R3. The sudden rise of current through R3 produces the voltage pulse. When the current falls to IV the UJT switches off and the cycle is repeated.
The On/OFF action in UJT is controlled by emitter current
armstron osillator and work
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.
Depends on what you need to know about it. First off, I'd use an oscilloscope. If it's set up correctly and you know how to `count graticules' that's really all you'll need to learn almost everything about your oscillator. IT should show you the wave forms at certain connection points, voltages as well as giving you some indication of the frequency. And if you want to know the current draw, you should probably have some type of milliamp meter on hand, which can usually be found in most miltimeters.
Explaine operation of UJT .
The R-C oscillator is also called a phase shift oscillator because the R-C filter creates a phase shift from input to output. The feedback portion of the oscillator (an amplifier) then serves to pump energy back into the filter.
The gradual loss of amplitude of an oscillator is called damping. Science book told me. =D
Relaxation of the eyelids is called blepharochalasis.
UJT is known as Uni Junction Transistor
any circuit which is used to generate an ac voltage without an ac input signal is called an oscillator.
by connecting the ujt with proper biasing resistors
Phase-shift oscillator Armstrong oscillator Cross-coupled LC oscillator RC oscillator
The relaxation phase of the heart cycle is called diastole, or the diastolic phase.
UJT is unijunction transistor where as BJT is bi- junction transistor.