The Potentiometer is an instrument which measures unknown voltage by balancing it with a known voltage. The known source may be DC or. Definition of DRYSDALE POTENTIOMETER: An ac potentiometer of the polar type, comprising a phase-shifting transformer and resistive voltage divider. Definition: The potentiometer which is used for measuring the phase and the magnitude of the unknown emf by comparing it with the known emf such type of.
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The operation of the AC potentiometer is quite complicated as compared to the DC potentiometer. Connects Facebook Youtube Videos. To obtain the necessary field distribution a split-phase scheme is used, part of the excitation being provided by a circuit containing a condenser and a potentiommeter in series.
The function of the series components is to maintain constant AC supply in the potentiometer by doing small adjustments in it. It also supplies 6 volts to potentiometers. Thus, the resultant voltage of the coordinate AC potentiometer is And the phase angle is given by. The working phenomenon of DC potentiometer and AC potentiometer is same.
What is AC Potentiometer? Definition, Types & Applications – Circuit Globe
Dryseale Alternating and Continuous Current Potentiometer. Voltmeter Calibration — The AC potentiometer directly measures the low voltages up to 1. Between the stators, there is rdysdale rotor having slots and winding which supplies voltage to the slide-wire circuit of the Potentiometer. As the vibration galvanometer has also to be adjusted for such changes, it is necessary to have a source of a very steady frequency and voltage for satisfactory working.
For higher frequencies a telephone may be used.
The AC potentiometer drysdwle be broadly classified as. It gives the accurate results in magnetic testing and precise testing of instrument transformers. Now to measure unknown e. Drysdale’s Alternating and Continuous Current Potentiometer The instrument comprises the standard Tinsley DC potentiometer of the time, with a phase shifter, Weston dynamometer voltmeter, selection and change-over switches and terminal panels for connection of galvanometers, DC and AC measuring and supply voltages.
Join our Mailing List by adding your email address below and be kept up to date with lots of information including: Now the in-phase component V A of the unknown e. This is accomplished by supplying it through a phase-shifting transformer which consists of a stator wound with a circuit, which produces a rotating field in a closely-fitting rotor.
Arrangements are provided for reversing the ammeter in order to eliminate the effect of stray fields. The AC potentiometers are classified by the value measured by the potentiometer dial and scales.
The potentiometer, which is the universal instrument by which currents are determined in terms of a difference of potential between the end of a known resistance, has been developed by C.
The working principle of the AC potentiometer is same as that of the DC potentiometer, i.
Hence the value of the unknown emf is known. Click on the Images For Detail. This ammeter must read correctly with alternating and ddysdale currents. Other Applications — The AC potentiometer is used for engineering measurement in which potentioemter accuracy of 0.
The potentiometer – is then thrown on to the A. Polar type Potentiometer In such type of instruments, two separate scales are used to measure magnitude and phase angle on some reference of the unknown e.
Web Design by Pure Energy. The main potentiometer current must be kept at some known constant value.
Further, the phase relation between the circuit to be measured and that supplying the potentiometer may have any value from to The “balance” is obtained by successive approximation of the usual adjustment of the potentiometer contacts dial and slide wire reading and of the phase-shifting transformer until the indicator shows no deflection.
Calibration of watt meter. In a phase-shifting transformer, there is a combination of two ring-shaped laminated steel stators connected perpendicularly to each other as shown in the figure.
The following are the important factor which must be considered for their operation. The phase drysale of the rotor emf is equal to potentiomdter movement angle from its original position and it is related to the stator supply voltage.
Please be assured that any amount you feel able to donate will make an immediate and significant impact. The whole arrangement of drysdalee winding is done in such a way that the magnitude of the induced potentiometrr in the rotor may change but it does not affect the phase angle and it can be read on the scale fixed on the top of the instrument. But there is one dryddale difference between their measurements, DC potentiometer only measures the magnitude of the unknown voltage.
There are two types of AC potentiometers: S 1 and S 2 are signs changing switches which are used to change the polarity of the test voltage if it is required for balancing the Potentiometer.
The instrument comprises the standard Tinsley DC potentiometer of the time, with a phase shifter, Weston dynamometer voltmeter, selection and change-over switches and terminal panels for connection of galvanometers, DC and AC measuring and supply voltages. Coordinate type Potentiometer In coordinate AC potentiometertwo separate potentiometers are caged in one circuit as shown in the figure.
Leave a Reply Cancel reply Your email address will not be published. Your email address will not be published. The known source may be DC or AC.
The higher voltage is measured by either using the volt box ratio or two capacitors in series with the potentiometer. The main circuit of the potentiometer must be supplied with alternating current of exactly the same frequency as that in the circuit to be measured, which means in practice that they must be supplied from the same source.
Measures voltage as magnitude and phase from reference voltage. One is directly connected to power supply and the other one is connected in series with variable resistance and capacitor. It has electrodynamometer type ammeter along with DC potentiometer and phase-shifting transformer which is operated by single phase supply.
The coordinate type potentiometer has two scales to read the inphase V 1 component, and the quadrature component V 2 of the unknown voltage V.
The AC potentiometer is also used for measuring the voltage which must be resolved into two components. There are two step-down transformers T 1 and T 2 which isolate potentiometer from the line and give an earthed screens protection between the winding.
And when both of them are equal the galvanometer indicates the null point.