ELEC 105, Spring 2004
Prof. Rich Kozick
Design and Implementation of a Majority Voting Circuit
Three partners in a small company have hired you to build a circuit
that will automate their voting. Each partner owns an equal share of
the company, so decisions are made by majority vote. You are to
design, build, and test the circuit. Please go through the following
- Write the truth table for the majority circuit.
- Write a Boolean expression for the circuit
in the standard sum-of-products form.
- Try to simplify the Boolean expression.
We will help you with the simplification.
- Draw a logic diagram for your simplified Boolean expression
using AND, OR, and NOT gates.
- Modify your logic diagram so that only NAND gates are
- Finally, connect your NAND gate design for the majority
function. Use 7400 ICs, switches for the inputs, and an LED for the
Test and demonstrate your
circuit for all input combinations in your truth table.