Design Challenge (Newbies) A Quiz Controller

[mechie]

Electronics Whizzes need not try :!:

OK try this...
Titaniumchuck wants a circuit that indicates which of four game contestants presses their button first. This thread
The circuit must indicate who pressed first by by lighting that contestant's bulb.
It should prevent other bulbs from being lit (so only the first button pressed will light a bulb).

There are several electronic circuits on the net but I don't see a circuit using RELAYS ONLY !
Don't cheat and post a circuit from somewhere else - design your own :!:

I reckon this is fairly easy in relay logic so have a go; pm me if you want to discuss an idea.

 

[kizzap]

just wondering is there a maximum of relays?

is there also the push buttons? what type? momentary or permanent?

do we show the outputs as well?

cool

Kieran

 

[mechie]

Use as many relays as you want but it is possible with four.
Use any pushbuttons you want - maybe 'push-to-test' or doorbell buttons for the contestants.
Show as much detail as you feel comfortable with, include outputs (lamps?) if you can.

 

[kizzap]

i am thinking that i may have got it. the circuit below has also got the ability to remove the other users past them the ability to press the switch. god this is hard!!! the relays and and switches are dual pole single throw. i used bulbs to remove the nessesity for polarisation.

hope someone can do better than this. I know realise the importance of the construction of things like ICs and transistors.

Kieran

 

[mechie]

Keep trying...

Don't give up yet, there is never just one way of solving a problem :wink:

OK Kizzap, if sw3 is operated it will stop the power reaching sw1 & 2 and so prevent them from working. R3 will energise and light bulb 3. R3 will also stop the power reaching R4's contacts: So far so good - But - if Sw4 is now operated ... ?
The switches here are wired as a kind of priority encoder - only the highest numbered switch can operate its relay, the relay contacts have a 'lowest takes priority' circuit - could these two elements be used to better effect :?:

 

[Phasor]

Perhaps a little ladder logic would help :wink: And remember that relays can have many sets of contacts...