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. DTL AND TTL LOGIC CIRCUITs? Bipolar transistorswere the first solid-state switching devices commonly used to implement digital logic circuits in the 1950s and 1960s. These c

Q. Express the waveform of the staircase type shown in Figure as a sum of step functions.

research paper on gauss,s law?

Q. For an n-channel JFET with V A = 350 V, I DSS = 10 mA, and V P = 3V, find V DS that will cause i D = 11 mA when v GS = 0.

Speech timer where max time is 5 minutes Use the switches for: start switch reset switch use the lights to represent: the “green” light meaning the

The circuit shown below is a DC charging and discharging circuit. a.  At t = 0 sec, switch S1 is thrown to position 1 ("pos1"). Write the mathematical expressions for and .

Calculate the approximate donor binding energy Calculate the approximate donor binding energy for Si (r = 11.7,m x n = 1.18 m 0 ) Solution: From E= m * n q 4 / 2(4 πε 0

Illustrate in detail digital encoders. Illustrate the following with their application: Photo-conductive cell Photo-voltaic cell

Q. Accelerator and Investment? Accelerator, Investment: Investment spending stimulates economic growth that consecutively stimulates further investment spending (as businesses

Define Multiple Inputs - Control System When there is much more than one input to a system, the superposition principle can be employed. This is that: The response to variou