I want to impress my 10 year old...

[Joe Cogan]

Hey everybody,

I want to show my son how smart his dad is. He asked me to make him a "electronic quiz board" for his school project. The board has 10 questions listed down the left side of the board and the 10 answers are listed down the right side. To do the quiz by hand, you would draw a line from the question to the correct answer (ie: Q1 to A4, Q2 to A9, etc...)

So he shows me this instruction sheet from his class. It shows how to hardwire the questions and answers together. The "quizer" uses a wire to touch the correct question/answer combination and if they get it right, a lightbulb lights up when you complete the circuit.

Well, that's not good enough for my son. (Tim "The Toolman" Taylor Syndrome.) We can make it better...

So, I thought of an idea:

1. Have 10 switches (SPDT or DPST or...) down the left side of the board for the questions.
2. Have 10 switches down the right side for the answers.
3. Have a green LED and a little "musical" chime for correct answers.
4. Have a red LED and a buzzer for incorrect answers.
5. Use a momentary Normally Open button to check your answer and a power supply (4 "D" cells)

The "Quizer" would "turn on" question switch 1 and answer switch 4. Then they would hit the NO button. The project would light the green LED if they were correct or the red LED if they were incorrect (buzzers and music too).

Well, I got all of the components I need from Radio Shack ($70 later...) and brought it to my workshop. I've been staring at it ever since.........

Anybody have a clue on how to wire this thing? Do I need AND gates or a PLC???? I'd really like to just hardwire it together without any added expense.

Somebody please help before my son does it himself and dis-owns me!!!!

Thanks!

Joe Cogan

 

[Exo]

This is the simplest i could come up with without using more electronic components.
A 'Q' switch is a question wich should be connected to the corresponding 'A' answer switch. S1 is the NO wich lights the led
you can add as many Q - A chains as you want in series with the existing 3 ...

When none of the Q - A chains are closed and you press S1 current will flow from V+ trough R2 through the red led to ground, indicating 'wrong'.
The green led doesn't get ground this way, preventing it from lighting
when one (or more) of the Q - A chains are closed and you press S1 current will flow from V+ trough the green led, through the Q - A and so on. lighting the green led. This ground signal will go trough D1 keeping the anode off the red led low preventing it from lighting. In this case full supply voltage is over R2 so make sure R2 can handle this.
D1 is there to keep the leds from beeing constantly on. Any normal diode will do .. (1N4148 for example)

Resistors R1 - R2 are 330 ohm - assuming the supply is +-5 Volts. (4 1.5V batteries will make 6V, wich will do). if your supply voltage is diffirent, the resistors might need change.

Now, about the buzzer and the music... A buzzer could be done, but how would you play music? Do you have any premade module wich plays music and just needs an 'on' signal? in this case more information about it would be welcome. If you want to make a circuit that plays music yourself then understand it will get a whole lot more complicated then just wiring some switches ...

 

[grrr_arrghh]

the problem with most solutions (including, possibly, the one above) is that you could just flick on all the switches, and hey presto all the LEDs light telling you that you have got it all right, which obviously you havn't.

personnaly, although it is more complicated, I would have a push switch for each question and one for each answer. The 'quizee' would have to push the switch on both the question and the answer at the same time for the LED to light. It would then latch on so that after answering all questions correctly, all the LEDs wouls be lit. (the point of having push switchesd is that it would be difficult to push all of them at the same time, making it harder to cheat!!)

and as suggested, unless you can buy a ready built module to make silly noises it could get quite complex. (wiring the module to your quiz game shouldn't be too much trouble - we can help you with that).

Possibly you could even include a circuit that resets the whole thing after 3 wrong answers...?

Hope this gives you a few ideas - I can expand further if you wish.

Tim

 

[Joe Cogan]

Thanks for the replies. I came up with another solution after writing the first request. Pardon the crude schematic.

There are a few limitations of this solution but I think it might get the job done without too much complexity. I'm using SPST switches for the "Question" selection and SPDT switches for the "Answer" column. The user will select only one question and one answer. If the hardwired switch that corresponds to the correct answer is "on", the green LED will light. If it is switched "off", the red LED will light. I'm pretty much ignoring the incorrect answers and focusing on the position of the "correct" switch. The circuit is completed when they press the NO momentary switch letting the user know if they got the answer correct or incorrect. Let me know what you think...

Joe

 

[CRW]

similar question

I have a similar project I'm working on, and would like some advice. I'm trying not to use any complex electronics if necessary.

My quiz board will have a column of questions on the left, with corresponding contacts along side. To the right are 2 multiple choice answers, "a" and "b", each with a corresponding contact. There are 2 lamps, green for "correct", and red for "incorrect". I would like to have 2 wires with probes to do the following: Place the first probe on a question on the left column, and the 2nd probe on either of the multiple choices to the right, on that same line. The lamps light up, either green or red for correct or incorrect.

I need the answer lights to light up only if the PROPER QUESTION is selected at the left. I have tried to come up with a diagram for this, but I have only been able to work it out where the left contacts are all jumped together, and therefore, if ANY of the questions selected, then the answer lamps will also light up when selected. I might as well not have the left probe at all.

I can wire it with the 2 probes and only one lamp, which only lights up if the correct answer is selected. And I can wire it with 2 lamps, but only 1 probe, to use for selecting the answer, "a" or "b". But I can't wire it to select both the individual question and the corresponding answer, using the 2 lamps.

I'm also not interested in using toggle switches or the master switch as used in the diagram above in this thread. And the questions and answers must be in the same line, not chosen from a column of answers( e.g. question #1 and answer #4).

What am I missing here? Thanx.

 

[stevez]

I wonder if you couldn't add two 3 input AND or NAND gates to Exo's solution to disallow the closure of more than one question switch and one answer switch. If more than one input were 'on' then use the output (or not output) to light a light, open the circuit to the lights, etc.