Servo Motor Trainer

A DC servo motor is widely used as an actuator in industrial control applications due to its high torque and ease of speed control. The dynamic performance of such systems depends on key motor parameters including moment of inertia, friction coefficient, time constant, and the electrical characteristics of the control winding such as resistance and inductance.
This training system is designed to experimentally determine both mechanical and electrical parameters of a DC servo motor and to evaluate its transfer function.
The system uses a small permanent magnet DC motor coupled with a generator. The generator serves dual purposes: speed sensing and electrical loading.
Motor speed is displayed automatically in revolutions per minute on a 4-digit panel meter. When the motor is switched on, a built-in circuit calculates and displays the time constant in milliseconds on a 3-digit panel meter. This eliminates the need for external measurement equipment.
The motor assembly is enclosed in a cabinet with transparent panels, allowing clear observation of the mechanical system.

Experiments :

• Torque-speed characteristics
• Inertia and friction parameter determination
• Back EMF constant measurement
• Time constant measurement
• Transfer function evaluation

Motor type :

• Permanent magnet DC motor

Speed measurement :

• 4-digit digital display (RPM)

Time constant display :

• 3-digit digital display (milliseconds)

**Measurement instruments : **

• 3° digit voltmeter
• 3° digit ammeter

Power supply :

• IC regulated DC power supply

Additional features:

• Built-in speed sensing generator
• Electrical loading capability
• Transparent cabinet enclosure

Learning Outcomes

• Understanding dynamic characteristics of DC motors
• Practical evaluation of mechanical and electrical parameters
• Analysis of system response and time constant
• Derivation and verification of transfer function

• Analysis of torque-speed characteristics
• Determination of motor parameters such as inertia and friction
• Digital display of time constant
• Transfer function evaluation
• Study of DC servo motor operation
• Integrated generator for speed sensing and loading
• Transparent enclosure for visual observation