DIODE GATES

We can make AND and OR gates from diodes. A diode is forward biassed if there is more than 0.6V across it.

 

 

 

Wiring Diagram:

 

 

 

Circuit Diagram:

Draw the circuit diagrams using the correct symbols.

Truth Table:

Use a voltmeter to measure the voltages ar A, B and C. You should get the following readings.

 

 

 

Conclusion:

The output at C does not reach 9V because of the voltage drop across the diode when it is conducting. When A or B goes to ground for the AND gate the current flows through the diode and C does not reach 0V.