quizzard change leds to 12 volt lights

[jace33]

ok this is the game i have purchased to save mucking around with making the circuit from scratch would like to use this game electronic buzzer kit and cut the led of and replace them with 12 volt lights.

Can anyone help with this if you know the cirucuit etc..


thanks

 

[Hero999]

That's a tricky question, it depends on the power supply and the LED outputs. What voltage does this thing run off?

There are several solutions.

You could replace each LED with an optoisolator and use it to drive a transistor or relay to control the 12V lights.

You could build a driver circuit with transistor to buffer the output from it so it can drive 12V lights.

You mighe be able to run this from 12V, remove the LEDs and current limiting resistors and replace them with low current 12V lights, but this is a very risky idea which could ruin the Quizzard.

The chances are you'll need to reverse engineer the Quizzard to some degree so you know the nature of the LED outputs, i.e. whether the LEDs are powred from a current source or sink.

Why have you decided to do this? Didn't the other circuits work? It's probably easier to get them working rather than reverse engineering and modifying an existing product.

 

[jace33]

the cirucuit runs off 4 aa batteries which comes to a total of 6 volt dc.

 

[jace33]

reason why to use this

i have decided to use this thought it might have been easy to use this as every other 12 volt cirucuit i have tried to make into a quiz buzzer thing has failed on me.

 

[Tarsil]

Use a MOS-FET (like IRF530 ) for driving each light. Conect the FET's gate trought a 4K7 res before the LED's resistor and remove the LED. I realy don't think that the game has a curent source. About conecting the MOS-FET&lights see other threads

 

[Hero999]

What if the LED has an NPN common collector driving it?

It simply won't work without a pull up resistor and logic inverter.

 

[Tarsil]

What if the LED has an NPN common collector driving it?

It simply won't work without a pull up resistor and logic inverter.

Hmm...You're wright. It wont work. He can try the solution above for 1-2 sec or so. If doesn't work ......just post that. He'l need anyway the mosfet's. Jut put them on a separate board.
I'm not very experienced in repairing stuff but I haven't seen a lot of common col driving LEDs.