Nothing To Do With Kits

[Guest ColinR]

A quiz is being organized for Xmas in my office and they want a buzzer setup like on the TV.

 

Anyone know how to wire a buzzer circuit, prferably with lights, so that the first one to hit the buzzer cuts out the others?

[Guest daveg]

Colin

 

That would require some J-K flip-flops and some nand gates...

 

You would need a circuit board, output transistor and power supply

 

If you had all that, you wouldn't be asking how to design it

 

Just shout

 

Dave

[Grim]

nah nah nah, all you need in a relay that once is tripped keeps itself on and switches the other team's off, and a push to break switch to cut it off. Well, a few of those but could be done!

[Guest ColinR]

Any chance of a translation and a diagram? I don't speak electronics. I need something fairly idiot proof to build. I'm the one who was testing for a spark on a bike and kicked it over while holding the plug!!! Ouch.

 

C

[Big Jim]

How many "stations do you want with buttons?"

 

(By the way, it's not me asking, Mutley is thinking about it)

[Grim]

good point jim, how many teams are you going to have? 2 teams shouldn't be too difficult, more might get complex, but could be done. i think!

[Guest Guy]

This can be made entirely from ford sierra electrics and uses 12V so it's safe. it will work for 2 teams, if you want every member of a team to have their own button then just parallel up more buttons.

 

This is how it works, while a switch is not pressed both relays are relaxed, this puts 12V on the opponents switch. As soon as one button is pressed the light comes on and the relay closes to sound the horn, this also disconnects the power from the opponents button to disable it.

 

The light bulb is on a separate circuit from the horn to protect it from voltage spikes.

 

Use two horns with different pitches to distinguish the sounds.

[Guest salty_monk]

Clever! Will require you to run it from a car battery though or aquire a pretty hefty 12v transformer to power those bulbs....

 

Most cheap 12v transformers put out 600ma max, you need nearly 2 amps just for the bulb on here plus whatever current the horn draws, (presumably only a couple of watts so a 2 amp supply should be adequate..)

 

You could presumably do the same with 240v (but I'm no expert) the horns at 240v might actually cost more than a hefty 12V transformer though...

[ibrooks]

Hefty 12v transformer - like maybe a battery charger?

 

Actually you'd be better running a charger permanently on a battery and run the whole setup from that.

 

Iain

[Guest salty_monk]

Output direct from a charger is pretty ropey (spikey) so I wouldn't suggest that.

Better as you say to run a charger to a battery or even buy one of those "power pack" affairs & run it off that with the trickle charger plugged in, wouldn't keep up with it for ever but long enough for a quiz I'm sure....

[Peter Bell]

Brilliant, what a neat solution Guy. I guess the only other thing is where does the battery go? in front or behind the seats?

Peter

[Guest chris brown]

in front under the table of cause

[Guest Guy]

I suggested a car battery because it's safe (electrically speaking) and simple for someone who is non electrically minded to connect up, also, being into cars the parts should be easy to get (most of us probable have most of them anyway).

 

The horns take a LOT of pulse energy that would just kill all but the most meaty power supply’s so I'd leave them alone, the car battery should last for ages anyway.

 

You could use a door bell instead of a horn (might also be easer on the ears ) most of these are 6V so you'd have to use a different lamp, 5V relays and different batteries (or just use the bell with a dropper resistor).

 

You could use the same circuit but run it on 240V using mains components if you were really brave but don't kill anyone.

 

Is it just the two teams or are more options needed?

[Guest ColinR]

What a wonderful club to belong to. If Douglas Adams had been a member I'm sure he would have got an answer to Life, the Universe and everything much quicker than he did.

 

We are planning a university challenge type quiz, but with harder questions, so the buzzer my not get much use Two teams will be the limit, one buzzer per team so they can stretch to reach it.

 

I have a spare battery tat came with the donor, and of course the one that came with the kit, I even have a battery charger, though the mains option sounds more fun. How would you wire it to blitz someone who gives a wrong answer?

 

Given the H&S concerns within the Civil Service I think the batery will have to go under the table in front of the seats (sorry Bill).

 

Thanks a lot for the help

 

Colin