Function of time base generator, Electrical Engineering

Q. Explain the function of time base generator in CRO.

Sol. Oscilloscopes are used to display a waveform that varies as a function of time. If the waveform is to be accurately reproduced, the beam must have a constant horizontal velocity. Since the beam velocity is function of deflecting voltage and the deflecting voltage is increased linearly with time. A voltage with this characteristic is called ramp voltage. If the voltage decreases to zero within the waveform reputedly reproduced this pattern is known as Saw tooth waveform.

During the sweep time, the beam moves from left to right across the circuit. The beam is deflected to right by the increasing amplitude of the ramp voltage and the fact that the voltage attracts the electrons during the retrace time or fly back time.

The beam returns to the left side of the    screen. The control grid is "grated off", which blanks out the beam during retrace time and prevents the undesirable signals pattern on the screen.

A continuous sweep CRO using UJT as a time base generator is shown in. the UJT is used to produce the sweep. When the power is applied the UJT is off and the changes exponentially through. The JUT emitter voltage rises towards.

And when reaches the peak voltage as shown in. the emitter to base. Diode becomes forward biased and the UJT trigger ON Which provides a low resistance discharge path and the capacitor dischargers rapidly.

The emitter voltage reaches the minimum value and JUT goes off. The capacitor, recharge and the cycle repeats.

To improve sweep linearity, two separate voltage supplies are used, a low voltages supply for UJT and a high voltage supply for the circuit. Is used fir continuous control of frequency within a range and is changed in step for range changing.

 

 

Posted Date: 7/12/2012 6:15:33 AM | Location : United States







Related Discussions:- Function of time base generator, Assignment Help, Ask Question on Function of time base generator, Get Answer, Expert's Help, Function of time base generator Discussions

Write discussion on Function of time base generator
Your posts are moderated
Related Questions
do you have a place where I can draw the equation out ?

First Quadrant or Class A chopper A chopper  two mode operation of class  A chopper  can be explained as follow.

Q. A dc shunt machine has an armature winding resistance of 0.12  and a shunt-?eld winding resistance of 50 . The machine may be run on 250-V mains as either a generator or a mot

the plot of amper circuital law by using matlap?

Q. A three-phase transformer bank consisting of three 10-kVA, 2300:230-V, 60-Hz, single-phase transformers connected in Y- is used to step down the voltage. The loads are connecte

Hysteresis results in a dissipation of energy Hysteresis results in a dissipation of energy which appears as a heating of the magnetic material. The energy loss associated wit

what is experimental setup for Butterworth filter?

I want to know whether the circuits for both methods(linear polarization resistance and electrochemical impedance spectroscopy) are same or not?

Explain Extrinsic Semiconductor. Extrinsic Semiconductor: An intrinsic semiconductor is able to conduct some current even at room temperature but as this is not helpful for t

Q.   What do you understand by demagnetizing and cross magnetizing effects of armature reaction in a d.c. machine. Derive the expression for calculation of demagnetizing and cross