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
Tag: DC motors
DC Motor Power Op-amp Speed Controller
Let’s consider the functional diagram below:
The D/A converter outputs a voltage directly related to the potentiometer position. However, the D/A converter’s output current is limited and not enough to … Read more
Features of Stepper Motors & How they are applied in Industrial Control
A stepper motor is a permanent magnet or variable reluctance DC motor that has the following characteristics:
- It is able to rotate in both directions
- It can move in precise angular increments
- It can sustain holding torque at zero speed
Factors to consider when selecting a Motor for a particular application
When selecting a motor for a specific industrial application, there are several factors and specifications that you should consider. We look at these factors that will guide you when choosing the appropriate motor for your industrial use.
The following are … Read more
Pulse Width Modulation (PWM) Speed Control of a DC motor
We can control the speed of a motor using an open loop control or closed loop control strategy. The open loop control is the simplest form of motor control; here we simply set the drive voltage value and the motor … 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
Speed Control of a DC Series Motor
The dc series motor has its windings and armature connected in series across the supply.
From the figure above, the armature current Ia also supplies the field, hence when Ia is large on starting for … 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