What is an eddy current dynamometer?
Eddy Current Dynamometer Eddy current dynamometers determine the torque of an engine by creating eddy currents. They are used extensively in the automotive industry to produce braking torque.
How do hydraulic dynamometers work?
Hydraulic dynamometer: It works on the principle of dissipating heat in the fluid friction rather than dry friction. Its construction is similar to that of the fluid wheel and it consists of an impeller coupled to the output shaft of the engine. The impeller rotates inside a casing filled with fluid.
Is eddy current dynamometer a transmission dynamometer?
The medium of torque transmission in Eddy Current dynamometers is a controlled magnetic field generated by a stationery coil. The developed torque in these dynamometers diminishes with reduction in speed with no torque developed at zero speed.
What are the advantages of eddy current?
The two advantages of eddy current in practical applications are: Sensitivity to surface defects: Able to detect defects of 0.5mm in length under favourable conditions. Accurate conductivity measurements: Dedicated conductivity measurement instruments operate using eddy currents.
What are dynamometers used for?
A dynamometer, or “dyno” for short, is a device for measuring force, moment of force (torque), or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed (rpm).
What is eddy current and its application?
Eddy currents are sometimes so strong, that metallic plate become red hot. Application:- (1)-In induction furnace, the metal to be heated is placed in rapidly varying magnetic field produced by high frequency alternating current. Strong eddy currents are set up in the metal produce so much heat that the metal melts.
What are the advantages of an eddy current dynamometer over other types of dynamometers?
An eddy current dynamometer is a special device with fewer losses, high efficiency, and more versatile as compared to the conventional mechanical dynamometer. In the eddy current dynamometer, the losses are less due to the absence of any physical contact between windings and excitation.
What are the main features of eddy current dynamometers?
The main features of eddy current dynamometers are as follows: The device operates in both clockwise and anti-clockwise directions Braking torque can be measured internally having no use of external devices The device is available in 13 models having the highest torque value of 399 N.m to that of 560 N.m
How is torque measured on an eddy current dynamometer?
This torque is measured by a sensor at the end of the arm on the dynamometer. The eddy current dynamometer, as a kind of load, is mainly used to measure the various characteristics of dynamic mechanical test equipment.
How does a dynamometer work?
In the case of the dynamometer, when the stator poles are excited with a DC supply which is connected to the stator. When the DC supply is connected, the stator coils are excited and a magnetic field is produced in the stator coils.
What is the function of the eddy current in a stator?
The eddy currents that are developed in the stator create opposition for the rotor movement by loading up the engine. As these currents develop heat there has to be a cooling apparatus in the device. The torque is calculated in the same way as that of the absorption dynamometer that is using the assistance of the moment arm.