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
Q. Illustrate procedure of Hex to Binary Conversion? It is also simple to convert from an integer hex number to binary. This is achieved by: Convert the Hex number t

What is AGP? AGP: The latest addition for many computer systems is the inclusion of the accelerated graphics port. This AGP operates at the bus clock frequency of the microproc

The mechanical power produced at the armature of a motor is: P = T a . (power is in watts if torque is N.m and    in rad/sec). Some of this will be lost due to friction and

Explain temperature dependence of electrical conductivity and resistivity in conductors. When the temperature is increased, there is a greater thermal motion in atoms that redu

Explain the magnetisation- curves of magnetic materials. The major characteristic of a ferromagnetic substance is domain structure of it. Every crystal of a ferromagnetic subst

please I need help in matlab to program complex expression in antenna diversity please

Why is an armature winding in d.c machine called closed winding.

Three Logic Levels are used and they are High, Low, High impedance state. The high and low are normal logic levels & high impedance state is electrical open circuit conditions. Tri

Q. Athree-phase, 600-kVA, 2300:230-V,Y-Ytrans- former bank has an iron loss of 4400 W and a full- load copper loss of 7600 W. Find the efficiency of the transformer for 70% full lo

We can use Ampere's Law to calculate the magnetic field in the core.