In the buzzer round of quiz contests, the question is thrown open to all the teams.The person who knows the answer hits the buzzer first and then answers the question. Some times two or more players hit the buzzer almost simultaneously and it is very difficult to detect which of them has pressed the buzzer first. In television shows, where the whole event is recorded, the actions are replayed in slow motion to detect the first hit. Such slow motions are possible only where huge funds are available to conduct the show.
For this reason buzzer rounds are avoided for quiz contests held in colleges. This project is an electronic quiz buzzer that is affordable by the colleges and even individuals. This project is useful for a 4-team quiz contest, although it can be modified for more number of teams. This system is sensitive. The circuit can detect and record the first hit contestant among all the contestants that may appear to be simultaneous. This project not only monitors the fastest finger, but also evaluates the performance of the contestants by saving marks of all participants in microcontroller registers as per Quiz Masters guidance.
This project uses 89C51 microcontroller. 16X2 LCD display is provided to alert the participants for the question and to display who is answering for the question. Quiz master can justify the answer by incrementing / decrementing the marks of particular team. Finally the quiz master can close the contest and he can display the marks obtaine by individual teams and winner details. Once the hit of a team is registered, all the buttons are automatically disabled. Even if any contestant tries to press the answer switch, the system will not respond. A buzzer is provided for audio indication of the switch bounce. Whenever a switch is bounced for answering, the system acknowledges the fastest bounced switch by a short beep sound. This buzzer is driven by an NPN transistor. This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.
Swiss Ball Exercises –
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working very good and so many features but box packing not same as shown in main pic