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
1. An analog information signal, whose maximum frequency is 6000Hz, is to be transmitted using a PCM system. The quantization error must not exceed the 1 % of the peak-to- peak an

Connect the two signals used in section 2 above to the "Multiplier" module. Make sure that you record the amplitude of each signal. Observe and record the resultant waveform in

Output Characteristics The output  or drain  characteristic of N - Channel  power MOSFET. When gate  is made positive with respect to the source an N type  channel  is formed

Operation - unijunction transistor: Operation : Imagine that the emitter supply voltage is turned biased and a small emitter reverse current flows. Then the intrinsic stand

howw to plot amper circuital law through matlap

Financing the power sector projects:   Massive investment is required for the targeted expansion of the sector. It has been estimated at Rs. 9 lakh crores in the further 10 yea

Determine the voltage across the 20- resistor in the following circuit of Figure (a) with the application of superposition.

Write a program implementing the conjugate gradient method (un-preconditioned). Solve the matrix equation corresponding to a finite difference node-spacing, h = 0.02m in x and y di

contribution of circuit theory on the health and quality of life of the citizen

Transmission Through a LiNb0 3 Plate Examine the transmission of an unpolarized He-Ne laser beam (?o= 633 nm) normally incident on a LiNb0 3 plate (ne = 2.29, no = 2.20) of thickn