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.
Q. What do you mean by Signal Processing? The essential feature of communication, control, computation, and instrumentation systems is the processing of information. Because of
A universal shift register can shift in both the left-to-right and right-to-left directions, and it has parallel-load capability. Draw a circuit for such a shift register.
Q. (a) For a JKFFwith JK = 11, the output changes on every clock pulse. The change will be coincident with the clock pulse trailing edge and the flip-flop is said to toggle, when T
Explain the Excess three codes - BCD to Decimal Conversion The Excess-3 representation of a number is based on Binary Coded Decimal. It is formed by taking the number in Binary
(a) Let a unit impulse of current i(t) = δ(t) be applied to a parallel combination of R = 3 and C = 1/2 F. Determine the voltage vC(t) across the capacitor. (b) Repeat (a) for
Components of PLC There are followings three main components of PLC : a.The power supply and rack. b.The central processing unit ( CPU) c.The input / output (I/O
Q. A voice message with W f = 2π(3×10 3 ) rad/s and Wrms = 2π(1 × 10 3 ) rad/s is transmitted over an FM broadcast system with standard emphasis. and compare the improvements due
What is a control word? It is a word kept in a register (control register) used to control the operation of a program digital device.
Three equal impedances of D ohms resistance and C inductive reactance are connected in a DELTA configuration. The line voltage is A00 volts. Determine the line current, phase cur
A TDM signal of the type is formed by samplingM voice signals at fs = 8 kHz. If the TDM signal then modulates the amplitude of a 4-MHz carrier for radio transmission, determine the
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