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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The reading of a sensitive dynamometer type ammeter drysdake the main circuit is noted. Web Design by Pure Energy. The indicator for low frequencies is a vibration galvanometer which must be closely tuned to resonate to the frequency of the circuit. 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.
Drysdale’s Alternating and Continuous Current Potentiometer. The potentiometer, which is the universal instrument by which currents are determined in terms of a difference of erysdale between the end of a known resistance, has been developed by C.
Since opening at the end ofover 5, children have visited the Centre. Drysdale for the measurement of alternating potentials. The first one is named as the in-phase potentiometer which is used to measure the in-phase factor of an unknown e. As the vibration galvanometer has also to be adjusted for such changes, it drysvale necessary to have a source of a very steady frequency and voltage for satisfactory working.
S 1 and S 2 are signs changing switches which are used drsydale change the polarity of the test voltage if it is required for balancing the Potentiometer.
Drysdale’s Alternating and Continuous Current Potentiometer – Computing History
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. Please be assured that any amount you feel able to donate will make an immediate and significant impact.
These children dyrsdale a space which is engaging and instructive, where they can feel a sense of adventure, exploration and surprise! Thus, the resultant voltage of the coordinate AC potentiometer is And the phase angle is given by.
Join our Mailing List by adding your email address below and be kept up to date with lots of information including:. Connects Facebook Youtube Videos. The whole arrangement of the winding is done in 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 fixed on the top of the instrument.
Related pages What is Potentiometer? Further, the phase relation between the circuit to be measured and that supplying the potentiometer may have any value from to This ammeter must read correctly with alternating and continuous currents. Click on the Images For Detail. There are two types of AC potentiometers: 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.
For higher frequencies a telephone may be used. 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.
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As it is necessary to have the splitphase circuit somewhere near the resonating point, it must be adjusted for changes of frequency. The main potentiometer current must be kept at some known constant value.
Join our Mailing List by adding your email address below and be kept up to date with lots of information including: We are extremely grateful for the very kind donation from Rosemary Helme of this Drysdale Alternating and Continuous Current Potentiometer. This is done by switching 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.
In order to obtain a balance, as indicated by the detecting instrument, it must be possible to give to the potentiometer current any phase displacement relative to that of the potential supplying it.
Where as, AC potentiometer measures both the magnitude and phase of unknown voltage by comparing it with known reference. These are adjusted until the A. Between the stators, there is laminated rotor having slots and winding which supplies voltage to the slide-wire circuit of the Potentiometer.
The function of the pllar components is to maintain constant AC supply in the potentiometer by doing potentiomeger adjustments in it. The potentiometer – is then thrown on to ptoentiometer A. One is directly connected to power supply and the other one is connected in series with variable resistance and capacitor. 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. There is a provision on the scale that it could read phase angle up to Arrangements are provided for reversing the ammeter in order to eliminate the effect of stray fields.
The phase-shifting transformer is usually supplied by single-phase current. Now to measure unknown e.
The “balance” is obtained by potentiomeger 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.
Now the in-phase component V A of the unknown e. Measures voltage as magnitude and phase from reference voltage.
The known source may be DC or AC. Applications of AC Potentiometer Measurement of self-inductance. 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.
What is DRYSDALE POTENTIOMETER? definition of DRYSDALE POTENTIOMETER (Science Dictionary)
The rotor has a winding on it which supplies the potentiometer current. Drysdale’s Alternating and Continuous Current Poteentiometer 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.
It has electrodynamometer type ammeter along with DC potentiometer and phase-shifting transformer which is operated by single phase supply. Polar type Potentiometer Dryssale such type of instruments, two separate scales are used to measure magnitude and phase angle on some reference of the unknown e.
By doing some adjustments in sliding contacts and rheostat, the whole circuit gets balanced and galvanometer reads zero at the balanced condition.