Wednesday, October 24, 2012

Quiz Show Buzzer using 7400 series device
My entry for Open 7400 Logic Competition 2012

A Quiz Show Buzzer was just built only with 74XX series device. A single 74LS373 Octal D-Type Flip Flop was used instead of several AND gates. Eight DATA INPUTs serve as quizzer’s user interface and the eight DATA OUTPUTs were connected to 8-input AND gate which provide the logic HIGH or LOW to GATE INPUT of 74LS373, the purpose of this is to disable all inputs after the first output became logic HIGH. The logic signal from DATA OUTPUTs can be use to drive a 7-segment display (for displaying quizzer’s number) and SSR (for indicator).

Circuit Maker 2000:!download|181p1|63856400|cm2000pro.rar|21049|0|0

Circuit Diagram:
quizbuzzer without 7segment

quizbuzzer with 7segment

Quiz Show Buzzer

Video Clips: