Addition switches (multiplier of 110) can also be used to give least count of 50 uv. The Potentiometer is provided with built-in standardisation curcuit, which renders standardisation dependent on setting of voltage dials. This potentiometer uses the Kelvin Varley arrangement shown below.This explains Laboratory type or Crompton's,Brooks deflectional,Standard Cell Dial,Vernier,Precision type,Multiple-Range potentiometers. This is essential so that once the instrument has been calibrated on x 1 range, calibration of the x 0.1 range is not necessary.The above requirement means that the E ac in above figure remains the same for both positions of range switch S.This condition is satisfied only when the total battery current has the same value for each measuring range. The design of circuit of a duo-range potentiometer should be such that it is possible to change the measuring ranges without re-adjusting the rheostat or changing the value of working of the battery. The circuit of a single potentiometer may be modified in a simple way to add a second range, which is usually by a second factor, such as 0.1 or 0.01, in order that the direct reading features of the original circuit may still be utilised. The single-range shown above is frequently constructed to cover a range of 1.6 V - though, of course, it can be designed for any desired within reasonable and practical limits.For example, a Crompton's potentiometer is designed to measure voltages up to 1.9 V by simply adding three more resistance steps to the main dial. It is quite comfortable to interpolate readings upto 1/5 of a scale division and therefore with this potentiometer it is possible to estimate the readings upto 0.0001 V.
The slide wire is provided with 200 scale divisions and since the total resistance of slide wire corresponds to a drop of 0.1 V, each division of slide wire corresponds to 0. Thus the dial has a total resistance of 150 Ω and in addition, the slide wire has a resistance of 10 Ω.The working current of the is 10 mA and therefore each step of dial switch corresponds to 0.1 V. For the case shown, the resistance of slide wire is 10 Ω and the dial resistors have a value of 10 Ω each. The circuit of a simple laboratory type potentiometer is shown in the below figure.There is one dial switch with fifteen steps, each having a precision resistor.There is also a single turn circular slide wire. Modern laboratory type potentiometers use calibrated dial resistors and a small circular wire of one or more turns, thereby reducing the size of the instrument. The long slide wire is awkward, and even for the length shown cannot be read to a very great degree of precision. The slide-wire type of potentiometer described in the previous article is not a practical form of construction. Crompton Controls DC injection Braking starters are suitable for controlled. Hybrid Solar Wind Power Generation System Pdf. This is Crompton Controls LT011 Issue 1 Tel. 00 is a battery powered control specifically designed for OEM lift applications. DC Drives, Variable Speed DC Motor Speed Control. Let's discuss how a DC potentiometer can compare emfs of two different cells.
Potentiometer Working Principle of Potentiometer.