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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Drysdale’s Alternating and Continuous Current Potentiometer The instrument comprises the standard Ootentiometer 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. The working phenomenon of DC potentiometer and AC potentiometer is same.
Voltmeter Calibration — The AC potentiometer directly measures the low voltages up to 1. Arrangements are provided for reversing the ammeter in order to eliminate the effect of stray fields.
Since opening at the end ofover 5, children have visited the Centre. The higher voltage is measured by either using the volt box ratio or two capacitors in series with the potentiometer. The potentiometer – is then thrown on to the A. It also supplies 6 volts to potentiometers. Join our Mailing List by adding your email address below and be kept up to date with lots of information including: Thus, the voltage and current may vary at different power factor.
The rotor has a winding on it potemtiometer supplies the potentiometer current. 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.
Applications of AC Potentiometer Measurement of self-inductance. One is directly connected to power supply and the other one is connected in series with variable resistance and capacitor. The operation of the AC potentiometer is quite complicated as compared to the DC potentiometer. 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.
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. The first one is named as the in-phase potentiometer which is used to measure the in-phase factor of an unknown e.
Coordinate type Potentiometer In coordinate AC potentiometertwo separate potentiometers are caged in one circuit as shown in the figure. The known source may be DC or AC. The function of the series components is to maintain constant AC supply in the potentiometer by doing small adjustments in it. Click on the Images For Detail. Where as, AC potentiometer measures drysdalee the magnitude and phase of unknown voltage by comparing it with known reference.
Hence the value of the unknown emf potentiometrr known. Dfysdale, the resultant voltage of the coordinate AC potentiometer is And the phase angle is given by. Drysdale’s Alternating and Continuous Current Potentiometer. The indicator for low frequencies is a vibration galvanometer which must be closely tuned to resonate to the frequency drysdzle the circuit.
The working principle of the AC potentiometer is same as that of the DC potentiometer, i. The following are the important factor which must be considered for their operation. Rdysdale the in-phase component V A of the unknown e. The AC potentiometer is also used for measuring the voltage which must be resolved into two components.
Calibration of watt meter. By doing some adjustments in sliding contacts and rheostat, the whole circuit gets balanced and galvanometer reads zero at the balanced condition. In this potentiometer, the magnitude of the unknown voltage is measured from one scale, and its phase angle is directly on the second scale. Drysdale for the measurement of alternating potentials. And when both of them are equal the galvanometer indicates the null point.
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. It gives the accurate results in magnetic testing and precise testing of instrument transformers. 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.
These are adjusted until the A. 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. Web Design by Pure Energy. The phase shifting transformer is connected to the potentiometer to vary the phase of the voltage on the current.
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.