This document describes designing and building a circuit to demonstrate the working of a NAND gate using transistors and diodes. It explains the components used including transistors, diodes, resistors, switches and an LED. It provides details on the circuit diagram and how the NAND gate works for different input combinations, with the output being high except when both inputs are high, demonstrating the NAND logic function. It concludes that the experimental output matches what is expected from the truth table.