Introduction
This experiment demonstrates how to design and implement a circuit that protects electronic devices from over-voltage conditions. When the input voltage exceeds a predetermined threshold, the circuit automatically disconnects the power supply, safeguarding sensitive components from damage.
Circuit Diagram
The diagram shows the key components required for an over-voltage protection circuit. It includes a voltage divider, a comparator, and a relay mechanism to disconnect the load when necessary.
Required Components
- Voltage regulator
- Relay
- Resistors (for voltage division and current limiting)
- Power supply (DC voltage source)
- Breadboard and connecting wires
- Diode (for flyback protection)
- Multimeter (for voltage measurement)
- Transistor (to drive the relay if required)
Assembly Steps
Step 1: Set Up the Voltage Divider
Build the voltage divider circuit to scale down the input voltage. This will allow you to monitor the voltage accurately using the comparator.
Step 2: Connect the Comparator
Wire the output of the voltage divider to the input of a comparator IC or a transistor-based detection circuit. Set the reference voltage to the desired threshold.
Step 3: Integrate the Relay
Connect the relay to the output of the comparator. The relay should control the power connection between the supply and the load, disconnecting it when over-voltage occurs.
Step 4: Test the Circuit
Use a variable power supply to gradually increase the voltage. Confirm that the relay activates at the preset threshold, disconnecting the load.
Experiment
Test the circuit by varying the input voltage. Observe and record the voltage at which the relay activates. Adjust the threshold by modifying the reference voltage or the resistor values in the divider.
Conclusion
This circuit provides an effective solution for protecting electronic devices from over-voltage conditions. By implementing a relay-based cutoff mechanism, you can ensure the safety of sensitive components and extend their lifespan.