De Sauty Bridge Components
De Sauty Bridge requires the following components:
Two variable resistors: A variable resistor is a type of resistor in which we can change the value of resistance according to the need. It allows the adjustment of voltage and current in the circuit according to Ohm’s law. The principle of variable resistor is based on changing the length of a resistive track by moving a wiper contact along it. The position of the wiper determines the effective resistance of the variable resistor.
Galvanometer or detector: It is an instrument used to measure electric current in a circuit. It is based on the principle of conservation of energy from mechanical to electrical form. It can measure low currents even of the order of microamperes. The magnitude of the current is indicated by a magnetic needle’s movement or that of the coil in a magnetic field. Different types of galvanometer are Tangent galvanometer, Mirror galvanometer, Astatic galvanometer etc.
AC source: An alternating current is an electric current that periodically reverses its direction and changes its direction with respect to time. An AC source provides alternating current to the circuit.
Standard capacitance: It is a type of capacitor which have a fixed value of capacitance.
Unknown capacitance: It is a capacitor whose capacitance value is unknown.
De Sauty Bridge
De Sauty Bridge is an AC bridge used to find the unknown capacitance in a circuit. French engineer Paul de Sauty invented it. De Sauty Bridge compares the unknown capacitance with another standard or known capacitor. It can also be used to compare the capacitors used in a circuit. De Sauty Bridge has a high degree of accuracy in measuring unknown capacitance over a wide range of capacitances. It works on the principle of null deflection. It is the simplest way to compare two pure(non-inductive) capacitors. The circuit design of the De Sauty Bridge is very simple and straightforward and the calculations are also simple. However, it can only measure capacitors that are free from dielectric loss. To overcome this disadvantage Grover modified the De Sauty Bridge by adding extra resistors.
Table of Content
- Defintion
- Working Principle
- Components
- Construction
- Formula
- Phasor Diagram
- Modified De Sauty Bridge
- Advantages and Disadvantages
- Application