AC generators can be utilized in high precision control systems. The AC generator rotor is rotated by the rotating shaft (i.e. the shaft from the motor being controlled). The output AC frequency is proportional to shaft speed. Zero crossings per … Read more
Tag: electrical machines
How to Wire an Industrial Control Motor
Option 1: With a Toggle Switch
Let’s consider a simple three-phase, 480V AC motor control circuit consisting of a contactor, overload block, control power transformer, power fuses or (you may use circuit breakers) and the associated components as illustrated … Read more
How to Perform a Brake Test on a DC Motor
Testing is usually performed on DC machines to establish efficiency and power losses. A brake test is a direct technique that involves applying a brake to a water-cooled pulley mounted on the motor shaft as demonstrated in Figure 1.0. This … Read more
Features and Applications of Instrument Transformers
Instrument transformers are used in the measurement of voltage, current, energy, and power in ac circuits. The main reasons why instrument transformers are employed in measurements are:
- To extend (multiply) the range of the measuring instrument.
- To isolate the measuring
What is the difference between a Power transformer and a Distribution Transformer?
Introduction
The transformer, in simple terms can be defined as the voltage regulator. It helps in stepping up and stepping down of the voltages. We all have seen transformers in our locality, where the current is passed from higher voltage … Read more
Speed Control of a DC Compound Motor
A compound motor is a combination of a series and a shunt-wound motor.
The Speed-torque characteristics for a compound motor
Speed Control of a DC Compound Motor
Speed is … Read more
DC Shunt Motor Speed Control
In the shunt motor, the motor winding is in parallel with the armature.
From the figure above, the supply current I = Ia + If . Unlike a series motor, if the load is removed … Read more
The Essential Components of An Electric Drive
Power electronics deals with the applications of solid-state electronics for the control and conversion of electric power. The conversion techniques require switching power semiconductor devices ON and OFF.
The block diagram below shows the essential components of an electric drive … Read more
Key Facts about Thyristor DC Motor Drives Operation
For motors up to a few kilowatts the armature converter draws power from either a single phase or 3-phase utility supply. For large motors, 3-phase power supply is preferred because the waveforms are much smoother although traction uses single-phase with … Read more
Step by Step Guide: How to Check and Test a Power Transformer
Testing of power transformers is continuous monitoring of faults in all units of such equipment and their timely removal after detection. All this is achieved with one objective continuation of the continuous activity of a significant node in the power … Read more