18-09-2012, 04:10 PM
SCHOOL/COLLEGE QUIZ BUZZER
[attachment=33986]
Manual buzzers used for quiz
competitions in schools and
colleges create a lot of confusion
in identifying the first respondent.
Although there are circuits using PCs
and discrete ICs, they are either too
expensive or limited to only a few
number of players.
The quiz buzzer circuit given here
can be used for up to eight players,
which is maximum in any quiz com-
petition. The circuit uses IC 74LS373
and a few passive components that are
readily available in the market.
The circuit can be divided into two
sections: power supply and quiz
buzzer.
One terminal of push-to-on
switches S1 through S8 is connected
to +5V, while the other terminal is
connected to the respective data input
pins. The switches are to be extended
to the players through cord wire. The
torch bulbs BL1 through BL8 can be
housed in boxes with the front side of
the boxes covered with a white paper
having the name or number of the
contestant written over it for easy
identification. Place the boxes above
the head level so that these can be
seen by the audience also.
[attachment=33986]
Manual buzzers used for quiz
competitions in schools and
colleges create a lot of confusion
in identifying the first respondent.
Although there are circuits using PCs
and discrete ICs, they are either too
expensive or limited to only a few
number of players.
The quiz buzzer circuit given here
can be used for up to eight players,
which is maximum in any quiz com-
petition. The circuit uses IC 74LS373
and a few passive components that are
readily available in the market.
The circuit can be divided into two
sections: power supply and quiz
buzzer.
One terminal of push-to-on
switches S1 through S8 is connected
to +5V, while the other terminal is
connected to the respective data input
pins. The switches are to be extended
to the players through cord wire. The
torch bulbs BL1 through BL8 can be
housed in boxes with the front side of
the boxes covered with a white paper
having the name or number of the
contestant written over it for easy
identification. Place the boxes above
the head level so that these can be
seen by the audience also.