Dakhara Teachogenretor 133

LDRP-ITR GANDHINAGAR TACHOGENERATOR

BY:DAKHARA PRADIP B DIV:D-D2 ROLL NO:133 ID NO:07EC072

Tachogenerator ► Tachogenerator

is a device which generates an electrical output directly proportional to the shaft speed. The voltage thus generated is fed to a speedometer for speed measurement and/or used as feed - back signal for controlling the speed of a rotating machine / equipment. In every automatic control system, since the system performance is directly related to the performance it becomes essential that the

DEFINATION ►

An electromechanical generator is a device capable of producing electrical power from mechanical energy, usually the turning of a shaft. When not connected to a load resistance, generators will generate voltage roughly proportional to shaft speed. With precise construction and design, generators can be built to produce very precise voltages for certain ranges of shaft speeds, thus making them well-suited as measurement devices for shaft speed in mechanical equipment. A generator specially designed and constructed for this use is called a tachometer or tachogenerator. Often, the word "tach" (pronounced "tack") is used rather than the whole word. By measuring the voltage produced by a tachogenerator, you can easily determine the rotational speed of whatever it's mechanically attached to. One of the more common voltage signal ranges used with tachogenerators is 0 to 10 volts.

TECHNOLOGY Motor and tachogenerator feature the patented skew-wound ironless rotors. The mono-axis design with the two commutator systems, facing each other in a patented arrangement, mounted on a single solid shaft, has excellent torsion characteristics and the highest frequency response possible.

TYPES OF TACHOGENERATOR 1.

DC TACHOGENERATOR

3.

AC TACHOGENERATOR

DC MOTOR -TACHOGENERATOR ► In

MicroMo's DC-Tachogenerators, the commutator and brushes are made of a high quality gold alloy. This results in a very low, constant transition-resistance, minimum starting friction and virtually insensitivity to environmental conditions. The linearity between rotational speed and generator-voltage makes these tachogenerators an ideal servo-component for speed indication

Priview of Structure

WORKING ►

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The purpose of a tachometer attached to the non-drive end of a brush type dc motor is to supply a feedback voltage to the motor`s drive, telling the drive what speed the motor is running. When the drive starts up it supplies a DC voltage to the motor matching the process required set point, thus motor runs at 10% of max speed the tacho will send back to the drive 10% of its maximum voltage (let's say the tacho's nameplate states 90Volts generated max at 1800 RPM and remains at 90V upto 5000RPM) which will be 9 Volt. When the brushes aren`t making good contact or the tacho`s signal path back to the drive gets broken, the drive will keep stepping up the dc output voltage since it would like to get some return voltage from the tacho. The result is a brush type dc motor that will ramp up speed wise too quick at initial start up. We replaced the brushes on the tacho and started the 150HP dc motor up and ramped it up gradually to full speed and after about 3min ramped it gradually down, making sure the drive doesn`t loose control over the motor.

HOW TO USE

OVERVIEW

Specifications ►

Input power put power Speed Holding

: 240 VAC;+O : 85 VDC,5.0 A : Better than 2%

out

Standard Features : Soft Start 0-90 Sec.,Operator Controls & Maximum Torque Limit ► ►

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Protective Features : Input fuses,low line voltage,line transients& isolated signal circuits Ambient

: 50 degree C

DIGITAL TACHOGENERATOR ► ► ► ► ► ► ► ►

Constructed on a single printed circut board 220/240 volt AC supply Compatible with computer and transducer signals Wide speed range with excellent speed holding Remote control options with no distance limit Factory preset controls for easy installation Built-in adjustable dynamic controls, acceleration/deceleration and torque limit Minimum downtime-controller can be changed in seconds Many special systems and control options

USE IN CEMENT INDUSTRY ► Speed

control or helper drive of rotary kiln, Proportional speed drives of supply feeders, clinker feeders and air quenching coolers ► Operation of constant weighing feeders, exhaust fan or cooler grate drivers for pressure control

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