Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Potentiometric type DVM: A potentiometric type of DVM, employs voltage comparison technique. In this DVM the unknown Voltage is compared with a reference voltage value is fixed by the setting of the calibrated potentiometer. The potentiometer setting is changed to obtain balance (i.e. null condition).When null conditions are obtained the value of the unknown voltage, is indicated by the dial setting of the potentiometer.
In potentiometric type DVMs, the balance is not obtained manually but is arrived at automatically. Thus, this DVM is in fact a self-balancing potentiometer .The potentiometric DVM is provided with a readout which displays the voltage being measured.
The block diagram of basic circuit of a potentiometric DVM is shown in.
The unknown voltage is filtered and attenuated to suitable level. This input voltage is applied to a comparator (also known as error detector). This error detector may be chopper. The reference voltage is obtained from a fixed voltage source. This L voltage is applied to a potentiometer R. The value of the feedback voltage depends upon the position of the sliding contact; the feedback voltage is also applied to the comparator.
The unknown voltage and the feedback voltages are compared in the comparator. The output voltage of the comparator is the difference of the above two voltages. The difference of voltage is called the error signal. The error signal is amplified and is fed to a potentiometer adjustment device which moves the sliding contact of the potentiometer. This magnitude by which the sliding contact moves depends upon the magnitude of the error signal. The direction of movement of slider depends upon whether the feedback voltage is larger or the input voltage is larger. The sliding contact moves such a place where the feedback voltage equals the unknown voltage. In that case, there will not be any error voltage and hence here will be no input to the device adjusting the position of the sliding contact and therefore it (sliding contact) will come to rest. The position of the potentiometer adjustment device at this point is indicated in numerical form on the digital readout device associated with it. Since the position at which no voltage appears at potentiometer adjustment device is the one where the unknown voltage equals the feedback voltage, the reading of readout device indicates the value of unknown voltage. The reference voltage source must be extremely stable and generally consists of a standard cell or a Zener diode sources.
List the different types of flags affected by the arithmetic and logic operations. Carry flag, Auxiliary carry flag , Parity flag, Sign flag, Zero flag
Power in Balanced Three-Phase Circuits The total power delivered by a three-phase source, or consumed by a three-phase load, is found simply by adding the power in each of the
For a discrete time unit step input x(kT), the output y(kT) of a system is shown below, Part (a) Obtain the Z-transform of the output signal y(kT). Part (b) F
What is the effect of overheating on the life of an electric insulator? An insulator is designed to withstand amount of heat. However, when an insulator is overheated so dielec
Switching Characteristics The switching characteristic of an IGBT during turn on and turn off time all shown in the sum of delay time and rise time gives the total tur
cross magnetizing components of armature reaction is...........
Q. Explain Position servo in a radar system? Figure depicts the essential elements of a position servo system. In a radar system, an electromagnetic pulse is radiated from an a
Q. With the help of a npn transistor circuit and wave forms explain the working of an astable multivibrator In astable multivibrator both transistors are coupled to each other
Although the low side is not as good a choice as the high-side local oscillator frequency, let an AM broadcast receiver be designed with a low-side local oscillator. As fc is varie
Q. Which are the different FET amplifiers? A FET can be used as a small-signal amplifier by connecting one of its lead to signal ground. The other two leads then serve as the i
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd