designing quiz lamp circuit

Assalamu'alaykum wr wb

bismillahirrohmanirrohim...
ill try to write down this article using english, altough my english is rather bad, hehe

i was thinking, how can i have quiz lamp that use to science competition occasionally. if i mere make some circuit that work if i press the button and lamp will light on, im sure that very easy. but the problems is what if the participants press the button approaching at same time. then the fastest one will get the light on.
and the others won't get their lamp light on until the fastest one release his button.

then i thought that i can use microcontroller, i sure will be easy but it will be price arm and length (haha). minimum system is expensive for this mini project. then i thought to using basic logic gate to redesign it. wow impressive, i can do it!

ok  this is my design, im using OR gate to design the circuit, it sure harder that design using microcontroller.

im design for 5 participants, in this case i just have to use 5 logic gate ICs. using 74LS32N for the OR logic gate. LM7805 to give 5 volts regulated voltage. and some capacitor for removing the ripple from rectifiers.

this is circuit for the button (larged scale)

this design same as push button, the button connected to the terminal as shown as header 2 above. when it pressed, it will be send 0 volt (logic 0). and when it released it will be send 5 volt (logic 1). in other words this is the active low design.

for actuator, relays are use to activating the lamp and bell (optional). i assume that bell and lamp use home voltage 220VAC 50Hz. and use relays that operate at 5 volt.

how it works?
1. assume that initial voltage is 5 volt for the button. so output from the OR logic gates  will be "1". and when it passes the NOT gate, it will become "0". then initial stages of each circuits is  "0" (remember that OR gate always produces "1" is one or more of its input is "1").
2. when one of them pressed, then the button circuit will be produces logic "0". noticed that all of OR logic inputs will be "0". and output from the NOT gate will be "1" .
3. while one of them produces "1". the others circuit will be locked into "0" condition. it means during the first contestant pressed until he released the others can't press it and light won't be turned on.
4. to control the lamp and bell, logic 0 will be send. why use logic "0"? i guess current from the gate is relatively small and needed other source to activated it. how i have logic "0", is the output logic when it active is "1"? its easy! just get them before it enters the NOT gate.

it easy to design right?
please correct me i wrong, if it about the design or the english, hehe


Wassalamu'alaykum wr wb
Fardhady HK Hanggara