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. Explain Kirchhoff current law? The basic laws that must be satisfied among circuit currents and circuit voltages are known as Kirchhoff 's current law (KCL) and Kirchhoff 's

Explain Commercial ADCs and DACs? Analog interface chips (AICs), like those in the Texas Instruments TLC32040 series, consist of all type of the analog components that explaine

Comparison  of Induction and Dielectric Heating After  studying the induction and  dielectric  heating  followings  points  may consider for  comparison  between  induction an

What are the 8086 interrupt types? Dedicated interrupts Type 0: Divide by zero interrupt Type 1: Single step interrupt Type 2:Non maskable interrupt Type 3: Breakpo

Consider the network shown in Figure (a). (a) Find the voltage drops across the resistors and mark them with their polarities on the circuit diagram. (b) Check whether the KV

Explain How to Represent Power Lines? The equivalent circuit of a power line depends on the length of the line and on the accuracy of the model required. In general, any power

hello... i want to design a 1 to 8 demux with 4bit inputs and output. but i dont know the architecture in gate level. please help me... in fact, i need the architecture in gate lev

Q. Can you explain twos Complement Division? 2's complement division is repeated 2's complement subtraction. The 2's complement of the divisor is calculated, and then added to

Parallel rlc circiut with a variable cap connected in series with a resistor

FIFO (First in First Out) stack is used in 8086.In this type of Stack the first stored information is retrieved first.