When the e.m.f. being measured is equal to the potentiometer voltage, the amplifier output Since polar potentiometer was developed by Dr. C.V. Drysdale , it is. Dr. C.V. Drysdales Alternating and Continuous Current Potentiometer The instrument comprises the standard Tinsley DC potentiometer of the time, with a phase. In a.c. potentiometers, another requirement is the control of stray e.m.f.s in fields Being a polar type, Drysdale – Tinsley a.c. potentiometer measures unknown.
|Published (Last):||25 August 2016|
|PDF File Size:||2.29 Mb|
|ePub File Size:||19.92 Mb|
|Price:||Free* [*Free Regsitration Required]|
One is directly connected to power supply and the other one is connected in series with variable resistance and capacitor. The whole arrangement of the winding is done in such a way that the magnitude of the induced emf in the rotor drysdle change but it does not affect the phase angle and it can be read on the scale fixed on the top of the instrument.
The instrument comprises the standard Tinsley DC potentiometer of the time, drywdale a phase shifter, Weston dynamometer voltmeter, selection and change-over polzr and terminal panels for connection of galvanometers, DC and AC measuring and supply voltages.
Web Design by Pure Energy. 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. Drysdale’s Alternating and Continuous Current Potentiometer.
Arrangements are provided for reversing the ammeter in order to eliminate the effect of stray fields. Applications of AC Potentiometer Measurement of self-inductance. We are extremely grateful for the very kind donation from Rosemary Helme of this Drysdale Alternating and Continuous Current Potentiometer.
Between the stators, there is laminated rotor having pogentiometer and winding which supplies voltage to the slide-wire circuit of the Potentiometer.
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.
Where as, AC potentiometer measures both the magnitude and phase of unknown voltage by comparing it with known reference. For higher frequencies a telephone may be used. Measures voltage as magnitude and phase from reference voltage. A rotation of the rotor of the phase-shifting transformer through o has the effect of producing a phase shift of the same value, and a pointer on the rotor axis indicates the phase angle on a suitably divided scale.
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. 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.
Please be assured that any amount you feel able to donate will potentiomeyer an immediate and significant impact. Potentiometeer working phenomenon of DC potentiometer and AC potentiometer is same. Since opening at the end ofover 5, children have visited the Centre. But there is one major difference between their measurements, DC potentiometer only measures the magnitude of the unknown voltage.
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.
Drysdale for the measurement of alternating potentials. The known source may be DC or AC. Calibration of watt meter.
Click on the Images For Detail. 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 resistance in series.
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. There are two types of AC potentiometers: The main potentiometer current must be kept at some known constant potentiomfter.
Further, the phase relation between the circuit to be measured and that supplying the potentiometer may have any value from to 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.
Thus, the resultant voltage of the coordinate Potentiomteer potentiometer is And the phase angle is given by. The indicator for low frequencies is a vibration galvanometer which must be closely tuned to resonate to the frequency of the circuit.
donate to us!
There is a provision on the scale that it could read phase angle up to Coordinate type Potentiometer In coordinate AC potentiometertwo separate potentiometers are caged in one circuit as shown in the figure. Now the in-phase component V A of the unknown e. Drysdlae order to obtain a balance, as indicated by the detecting instrument, it polr be possible to give to the potentiometer current any phase displacement relative to that of the potential supplying it.
Related pages What is Potentiometer? The phase displacement of the rotor emf is equal to rotor movement angle from its original position and it is related to the stator supply voltage. The phase-shifting transformer is usually supplied by single-phase popar. It has electrodynamometer type ammeter along with DC potentiometer and phase-shifting transformer which is operated by single phase supply.
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. Connects Facebook Youtube Videos. As it is necessary to have the splitphase circuit somewhere near the resonating point, it must be adjusted for changes of frequency.
Join our Mailing List by adding your email address below and be kept up to date with lots potenitometer information including:. Potetniometer children deserve a space which is engaging and instructive, where they can feel a sense of adventure, exploration and surprise! The potentiometer – is then thrown on to the A. When current start flowing from stators, the rotating field is developed around the rotor and due to it e.
The first one is named as the in-phase potentiometer which is potentiomwter to polsr the in-phase factor of an unknown e. 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. Join our Mailing List by adding your email address below and be kept up to date with lots of information including: