All Topics  
Bridge circuit

 

 
   Email Print
   Bookmark   Link
 

 

Bridge circuit
 
 
  Topics Bridge circuit Topic Home

A bridge circuit is a type of electrical circuit in which the current in a conductor splits into two parallel paths and then recombines into a single conductor, thereby enclosing a loop. It was originally used for measurement purposes, but can also be used in power supplies
Power supply

Power supply is a reference to a source of electrical power. A device or system that supplies electrical or other types of energy to an output External electric load or group of loads is called a power supply unit or PSU....
.

The best-known bridge circuit, the Wheatstone bridge
Wheatstone bridge

A Wheatstone bridge is a measuring instrument invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843....
, was invented by Samuel Hunter Christie
Samuel Hunter Christie

Samuel Hunter Christie was a British scientist and mathematician. He studied mathematics at Trinity College, Cambridge. He was particularly interested in magnetism, studying the earth's magnetic field and designing improvements to the magnetic compass....
 and popularized by Charles Wheatstone
Charles Wheatstone

Knighthood Charles Wheatstone Fellow of the Royal Society , was a United Kingdom scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope , and the Playfair cipher ....
, and is used for measuring resistance
Electrical resistance

The electrical resistance of an object is a measure of its opposition to the passage of a steady electrical current. An object of uniform cross section will have a resistance proportional to its length and inversely proportional to its cross-sectional area, and proportional to the resistivity of the material....
.






Discussion
Ask a question about 'Bridge circuit'
Start a new discussion about 'Bridge circuit'
Answer questions from other users
Full Discussion Forum



Encyclopedia


A bridge circuit is a type of electrical circuit in which the current in a conductor splits into two parallel paths and then recombines into a single conductor, thereby enclosing a loop. It was originally used for measurement purposes, but can also be used in power supplies
Power supply

Power supply is a reference to a source of electrical power. A device or system that supplies electrical or other types of energy to an output External electric load or group of loads is called a power supply unit or PSU....
.

Wheatstone Bridge
The best-known bridge circuit, the Wheatstone bridge
Wheatstone bridge

A Wheatstone bridge is a measuring instrument invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843....
, was invented by Samuel Hunter Christie
Samuel Hunter Christie

Samuel Hunter Christie was a British scientist and mathematician. He studied mathematics at Trinity College, Cambridge. He was particularly interested in magnetism, studying the earth's magnetic field and designing improvements to the magnetic compass....
 and popularized by Charles Wheatstone
Charles Wheatstone

Knighthood Charles Wheatstone Fellow of the Royal Society , was a United Kingdom scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope , and the Playfair cipher ....
, and is used for measuring resistance
Electrical resistance

The electrical resistance of an object is a measure of its opposition to the passage of a steady electrical current. An object of uniform cross section will have a resistance proportional to its length and inversely proportional to its cross-sectional area, and proportional to the resistivity of the material....
. It is constructed from four resistors, one of which has an unknown value (Rx), one of which is variable (R2), and two of which are fixed and equal (R1 and R3), connected as the sides of a square. Two opposite corners of the square are connected to a source of electrical current, such as a battery. A galvanometer
Galvanometer

A galvanometer is a type of ammeter: an instrument for detecting and measuring electric current. It is an Analogue electronics electromechanical transducer that produces a rotary deflection, through a limited arc, in response to electric current flowing through its coil....
 is connected across the other two opposite corners. The variable resistor is adjusted until the galvanometer reads zero. It is then known that the ratio between the variable resistor and its neighbour is equal to the ratio between the unknown resistor and its neighbour, and this enables the value of the unknown resistor to be calculated.

The Wheatstone bridge has also been developed to measure impedance in AC circuits, resulting in designs such as the Wien bridge, the Maxwell bridge
Maxwell bridge

|- align = "center"||width = "25"|| A Maxwell bridge is a type of Wheatstone bridge used to measure an unknown inductance in terms of calibrated Electrical resistance and capacitance....
 and the Heaviside bridge. All are based on the same principle, which is to compare the output of two potentiometer
Potentiometer

A potentiometer is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used , it acts as a variable resistor or Rheostat....
s sharing a common source.

In power supply design, a bridge circuit or bridge rectifier is an arrangement of diode
Diode

In electronics, a diode is a two-terminal device .Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional electric current property....
s or similar devices used to rectify an electric current, i.e. to convert it from an unknown or alternating polarity to a direct current of known polarity.

In some motor controller
Motor controller

A motor controller is a device or group of devices that serves to govern in some predetermined manner the performance of an electric motor. A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torq...
s, a H-bridge
H-bridge

An H-bridge is an electronic circuit which enables a voltage to be applied across a load in either direction. These circuits are often used in robotics and other applications to allow DC motors to run forwards and backwards....
 is used to control the direction the motor turns.

See also

  • Fontana bridge
    Fontana bridge

    A Fontana bridge is a type of bridge circuit that implements a wide frequency band voltage-to-current converter. The converter is characterized by a combination of positive and negative feedback loops, implicit in this bridge configuration....
  • Graetz bridge
  • Kelvin bridge
    Kelvin bridge

    A Kelvin bridge is a measuring instrument invented by William Thomson, 1st Baron Kelvin. It is used to measure an unknown electrical resistance below 1 Ohm....
  • Lattice filter
  • Maxwell bridge
    Maxwell bridge

    |- align = "center"||width = "25"|| A Maxwell bridge is a type of Wheatstone bridge used to measure an unknown inductance in terms of calibrated Electrical resistance and capacitance....
  • Phantom circuit
    Phantom circuit

    In telecommunication and electrical engineering, a phantom circuit is an electrical circuit derived from suitably arranged wires with one or more conductive paths being a circuit in itself and at the same time acting as one conductor of another circuit....
     - a use of balanced bridge circuits
  • Wheatstone bridge
    Wheatstone bridge

    A Wheatstone bridge is a measuring instrument invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843....
  • Wien bridge oscillator
    Wien bridge oscillator

    A Wien bridge oscillator is a type of electronic oscillator that generates sine waves. It can generate a large range of frequencies. The circuit is based on an electrical network originally developed by Max Wien in 1891....
  • Bridge T circuit


External links

- Chapter 8 from an online book. - With balance equations