Bridge rectifiers

Principle

Now that the students have become familiar with the rectifying quality of diodes, this experiment should demonstrate the functioning of the bridge circuit normally used in practice. They should see that the current flows through the load resistor in the same direction in each half period of the alternating current when 4 diodes in a bridge rectifier are used.
Since oscilloscopes and alternating voltage generators with an extremely low frequency are generally not used in student experiments, the behaviour of the bridge rectifier in an alternating current circuit is simulated by reversing the polarity of a direct current power source to determine the direction of the current.
You should encourage the students to predict the behaviour of the circuit after reversing polarity of the power source.
Aside from the correct answer, here are some other predictions they might come up with:

• No current will flow after reversing polarity because the diodes only let the current flow in one direction.
• The current will flow in the opposite direction after reversing polarity of the voltage.

Benefits

• No additional cable connections between the building blocks needed - clear arragned and quick setup
• Contact saftey due to puzzle blocks system
• Corrosion-free gold plated contacts
• Doubled earning sucess: Electric circuit diagram on top, real components can be seen unterside

Tasks

How can both half periods of alternating current be used to create direct current?

Investigate on which path and in which direction the current flows through the bridge rectifier with various polarity scenarios for the voltage.