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.
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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. This is done by ptentiometer it over on to a continuous current circuit, which is adjusted until a balance is obtained at the proper setting, when a Weston cell is connected up in the usual manner.
It also supplies 6 volts to potentiometers. The working phenomenon of DC potentiometer and AC potentiometer is same. Coordinate type Potentiometer In coordinate AC potentiometertwo separate potentiometers are caged in one circuit as shown in the figure. 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 po,ar and terminal panels for ddysdale of galvanometers, DC and AC measuring and supply voltages.
Now the in-phase component V A of the unknown e.
Please be assured that any amount you feel able to donate will make an immediate and significant impact. Between the stators, there is laminated rotor having slots and winding which supplies voltage to the slide-wire circuit of the Potentiometer.
Now to measure unknown e. One is directly connected to power supply and the polag one is connected in series with variable resistance and capacitor. Further, the phase relation between the circuit to be measured and that supplying the potentiometer may have any value from to 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.
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.
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The rotor has a winding on it which supplies the potentiometer current. Drysdale for the measurement of alternating potentials. 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. Potsntiometer are adjusted until the A.
The whole arrangement of the winding is done polaf such a way that the magnitude of the induced emf in the rotor may change but it does not affect the phase angle and it can be read on the scale optentiometer on the top of the instrument. In order potetniometer obtain a balance, as indicated by the detecting instrument, it must be pofentiometer to give to the potentiometer current any phase displacement relative to that of the potential supplying it.
Web Design by Pure Energy. Join our Mailing List by adding your email address below and be kept up to date with lots of information including:. Thus, the resultant voltage of the coordinate AC potentiometer is And the phase angle is given by.
Calibration of watt meter. It has electrodynamometer type ammeter along with DC potentiometer and phase-shifting transformer which is operated by single phase supply. Join our Mailing List by adding your email address below and be kept up to date with lots of information including: The reading of a sensitive dynamometer type ammeter in the main circuit is noted.
Drysdale ac polar 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. Further references can be found at: Polar type Potentiometer In such type of instruments, two separate scales are used to measure magnitude and phase angle on some reference of the ddrysdale e.
This ammeter must read correctly with alternating and continuous currents. The potentiometer – is then thrown on to the A.
Click on the Images For Detail. The indicator for low frequencies is a vibration galvanometer which must be closely tuned to resonate to the frequency of the circuit.
By doing some adjustments in sliding contacts and rheostat, the whole circuit gets balanced and galvanometer reads zero at the balanced condition.
We are extremely grateful for the very kind donation from Rosemary Helme of this Drysdale Alternating and Continuous Current Potentiometer. Drysdale’s Alternating and Continuous Current Potentiometer.