Transformer Voltage Conversion Experiment

Objective

The objective of this experiment is to demonstrate the use of a transformer to step up or step down voltage levels between two circuits. We'll explore the relationship between the number of turns in the primary and secondary windings and the corresponding voltage conversion.

Components Required

• 1 x Transformer (e.g., 12V to 240V step-up or 240V to 12V step-down)
• 1 x AC Power Source (or AC signal generator)
• 1 x Multimeter (to measure voltage)
• 1 x Load resistor (appropriate rating for secondary voltage)
• Connecting Wires
• Breadboard (optional)

Theory

A transformer works on the principle of electromagnetic induction, where a changing magnetic field in the primary coil induces a voltage in the secondary coil. The voltage conversion ratio between the primary and secondary sides is proportional to the ratio of the number of turns in each coil, as per the equation:

V_s / V_p = N_s / N_p

Where V_s and V_p are the secondary and primary voltages, and N_s and N_p are the number of turns in the secondary and primary windings, respectively. Transformers are widely used for voltage conversion in power systems and electronic devices.

Circuit Diagram

To set up the circuit for this experiment, follow these steps:

1. Identify the primary and secondary windings of the transformer. These are usually labeled on the transformer casing.
2. Connect the primary winding terminals to the AC power source. Ensure proper polarity and secure the connections tightly.
3. Attach the secondary winding terminals to the multimeter leads to measure the output voltage. Configure the multimeter to AC voltage mode.
4. If using a load resistor, connect it across the secondary winding terminals to simulate a practical load. Ensure the resistor is rated appropriately for the secondary voltage.
5. Double-check all connections to ensure there are no loose wires or short circuits before powering on the AC source.

Follow all safety precautions when working with AC power to avoid electric shocks or damage to the equipment.

Experimental Setup

1. Connect the primary winding of the transformer to the AC power source.

2. Connect the multimeter across the secondary winding to measure the output voltage.

3. Optionally, add a load resistor across the secondary to simulate a practical application.

Procedure

1. Set up the transformer as per the circuit diagram. Ensure proper safety precautions when working with high voltages.
2. Turn on the AC power source and observe the input voltage to the primary winding using a multimeter.
3. Measure the output voltage across the secondary winding using the multimeter.
4. Compare the measured output voltage with the expected voltage based on the turns ratio of the transformer.
5. Repeat the experiment by using a different transformer with a different turns ratio (if available) and note the change in output voltage.
6. If using a load resistor, observe how the output voltage is affected when a load is applied.

Results and Observations

Record the measured primary and secondary voltages and compare them with the expected values. Observe how the turns ratio affects the voltage conversion, and document any variations when a load is added.

Conclusion

This experiment demonstrates the basic working principle of a transformer in converting voltage levels. By adjusting the number of turns in the primary and secondary windings, a transformer can step up or step down AC voltages, making it a key component in electrical power systems and electronic circuits for voltage regulation and isolation.