types of ammeter ppt

1. types of ammeter
BY
SAGAR PARTE
ROLLNO :- 20
TE ETRX

2. INTRODUCTION
• An ammeter is a measuring instrument used
to measure the electric current in a circuit.

3. History
• The relation between electric current, magnetic fields
and physical forces was first noted by Hans Christian
orsted.
• who, in 1820, observed a compass needle was
deflected from pointing North when a current flowed in
an adjacent wire.
• Frist ammeter 

4. Types of ammeter
 Moving-coil ammeters
 Electrodynamic ammeters
Moving-iron ammeters
Hot-wire ammeters
Digital ammeters
Integrating ammeters

5. Moving-coil ammeters
It uses magnetic deflection, where current passing
through a coil causes the coil to move in
a magnetic field.

6. Electrodynamic ammeters
An electrodynamic movement uses an electromagnet
instead of the permanent magnet of the d'Arsonval
movement.

7. Moving-iron ammeters
Moving iron ammeters use a piece of iron which
moves when acted upon by the electromagnetic
force of a fixed coil of wire

8. Hot-wire ammeters
In a hot-wire ammeter, a current passes through
a wire which expands as it heats

9. Digital ammeters
Digital ammeter designs use a shunt
resistor to produce a calibrated voltage
proportional to the current flowing.

10. Integrating ammeters
In these ammeters the current is summed
over time, giving as a result the product of
current and time; which is proportional to the
energy transferred with that current.