Using switching circuit to change connection routing in quiz game

Thread Starter

jules

Joined Aug 3, 2009
12
I’m designing and updating a homemade quiz game idea from many years ago. There are 12 questions on the left of the board, with 12 answers on the right. A correct answer lights a green LED, a wrong answer lights a red LED through a MOSFET switch, see diagram. The questions and answer pins are hardwired beneath the board so can’t be seen. So for example Q1 goes to A8, Q10 to A3….and so on for all 12 connections.
I've already used the board upside down so the wiring is inverted and Q and A columns are reversed, but this gives a maximum of two different wiring patterns.
The problem is that the connections cannot be changed without rewiring, see diagram, so the pattern can be easily remembered after a few turns.
Is there a way the 12 (or more) questions can be assigned to 12 different answers digitally?
I have played with a rotary switch with no success but think there must be another way.
I’m thinking of up to say 5 wiring options, but could be more, so option 1 connects the Q/A links in one way, option 2 in another way and so on. An 8 digit LED display could show which of the 5 options is selected, so the Q/A sheets can be pre-made to match.
Of course the question and answer connections must first be known to the quizmaster to match right and wrong written answers.

I’m using a 6V supply (4x1.5V) and the red and green LED current is limited to 20mA with a dropper resistor.

Thanks for any suggestions.
 

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Thread Starter

jules

Joined Aug 3, 2009
12
What is the characteristics of the signals between Q and A? Are they digital? Analog? What levels?
The Q and A connections are simply a wired connection, so analogue. They just complete a basic series circuit.
20mA flows when answer chosen, lighting up either red or green leds.
 

BobTPH

Joined Jun 5, 2013
8,664
Write the questions on a PC board. Etch the back with the pattern of connections. Slide the oars into a housing with a connector at the back that makes the in and out connections.
 

BobTPH

Joined Jun 5, 2013
8,664
You are missing the point. You need some mechanism that changes the connections for each set of questions. Come up with that first, and then we can talk about the electronics to implement it.

It can be a mechanical arrangement, like I proposed, or you could use a microcontroller and enter an answer key for each set of questions.
 

MisterBill2

Joined Jan 23, 2018
17,814
OK, the expensive simple scheme will be a 12 pole multiple position rotary switch.That will make a different arrangement for each switch position available, limited by the number of positions. A cheaper version will be a 24 (or more) position IC socket, Then either plug in wire jumpers or a 24 pin header for each set of links. .That same scheme can use a 25 position "D" connector, which may be more available used and cheap.
Doing it with actual electronics will be quite a bit more complex.
 
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