Galvanometers

Galvanometers

 

      Galvanometer is a very sensitive device to deflect current in the circuit. It is highly sensitive device. It has very low resistance. It is always connected in series. A galvanometer is a type of ammeter: an instrument for detecting and measuring electric current It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field. .

Galvanometers were the first instruments used to detect and measure electric currents. Sensitive galvanometers were used to detect signals from long submarine cables, and were used to discover the electrical activity of the heart and brain.

One problem with the tangent galvanometer is that its resolution degrades at both high currents and low currents. The maximum resolution is obtained when the value of θ is 45°. When the value of θ is close to 0° or 90°, a large percentage change in the current will only move the needle a few degrees.