How Eddy Speedometer Operates?

A speedometer, as is very clear from the name itself is a speed meter used for measuring and displaying vehicle’s speed. Speedometers were unveiled in the market for consumers in 1900s. From 1910 onwards, these started to be sold as standard equipment. The equipment was invented by Charles Babbage and was initially secured to locomotives. Lately speedometers are secured in motor vehicles. In modern world, the similar technology used for boats is referred as pit log and when used for aircrafts, it is referred as airspeed indicator. This article would discuss How Eddy Speedometer Operates?

• Eddy Speedometer works with the aid of a rotating flexible cable. This flexible cable is driven by the gearing connected to vehicle-transmission’s output.
• As the vehicle witnesses motion, the speedometer cable is turned by the speedometer gear assembly immediately. It eventually leads to a speedometer mechanism.
• There is also a small magnet attached to the speedometer cable and which deals with a speedcup hinged to the pointer’s shaft. This activity takes place on analogue speedometer instrument.
• When magnet rotates, the magnetic field starts changing. This results in circular currents in cup and also creates another magnetic field.
• Finally, the magnet ends up generating force on the cup and drags it and thus the speedometer pointer also gets dragged. The pointer moves in its rotation direction.
• The torsion spring keeps the pointer shaft towards zero.
• The force exerted on the cup is made to increase with the magnet’s speed of rotation.
• The force exerted on the cup is proportional to the speed of the car.
• The deflection of the spring is proportional to the force exerted.
• The pointer’s angle is proportional to the speed.
• At certain speed, the pointers stay inactive. A pointer points to the appropriate number on the dial of the speedometer.
• The calibration of the return spring is done. The various factors such as "the final drive ratio in the differential", tailshaft gears’ ratio that propel flexible cable, driven tires’ diameter etc. are also taken into consideration.
• When the vehicle is running in reverse gear, eddy speedometer is not able to show the speed of the vehicle. The reason being, the cup turns in opposite direction.

Many modern day speedometers require the use of Speedometer Drives. There are several Speedometer Drives Suppliers in India. Speedometer Drives Exporters in India are counted amongst the notable exporters in the world. The suppliers and exporters from India are known to provide highest quality Speedometer Drives at very competitive prices.

Gautam Jain is a Owner of Mini Meters Manufacturing Co., a leading manufacturer and supplier of Electronic Instrument Clusters, Voltmeter, and more.