Electronic decision unit

Thread Starter

electronics123

Joined Feb 22, 2020
35
a charity organises quizzes to raise funds. They require an electronic decision unit to indicate which of three quiz teams presses their buttons first. The unit should include light and sound.

I need help with designing the circuit and test procedures as well as calculation

I am not allowed to use programmable components
The organisation has required the use of at least four logic gates, one input subsystem to provide a digital signal for logic gates an output subsystem, funcitonal intergration and power only from batteries or low voltage power supply unit(maximum 12 volts)

CAN YOU HELP ME?
 

MisterBill2

Joined Jan 23, 2018
5,188
hi 123,
Welcome to AAC.
Is this a College or School assignment.?
Why is a programmable MCU not allowed.?
E
Why use an MCU of any type? These devices have been built even using the old style electromechanical relays. The logic is fairly simple. Gates and flipflops are all that is needed. If the sound does not need to be really loud, and the light does not need to be terribly bright, then the system could run on a single 9 volt battery, otherwise a set of 4 "D: cells could be the power source.
This does sounds a lot like a school exam in a digital logic course. But it might just be a homework assignment.

It can be done as simply as 3 J-K flipflops (CD4027) and a 3 input OR gate. The input circuit can simply be a 4049 hex inverter with some small capacitors and 220 ohm pull down resistors. When any FF is triggered it's Q_ feeds the or gate removing the "J" input, so that the next FFs can not toggle. I did omit the reset circuit and the announcers but they are simple.
 

WBahn

Joined Mar 31, 2012
25,230
a charity organises quizzes to raise funds. They require an electronic decision unit to indicate which of three quiz teams presses their buttons first. The unit should include light and sound.

I need help with designing the circuit and test procedures as well as calculation

I am not allowed to use programmable components
The organisation has required the use of at least four logic gates, one input subsystem to provide a digital signal for logic gates an output subsystem, funcitonal intergration and power only from batteries or low voltage power supply unit(maximum 12 volts)

CAN YOU HELP ME?
This is pretty clearly an assignment of some kind -- and a pretty common one.

Make your best attempt to get started and show that. We can then offer feedback and small suggestions on what to do differently or what to do next.

You might start with a detailed sequence of events that goes through one cycle of operation. That will help you identify actions that are necessary but only implied in your present description.
 

MaxHeadRoom

Joined Jul 18, 2013
20,000
I agree, too bad about the 'no MCU' a small 8pin footprint micro would do it a cinch.
Strange a charity org that requires it stipulates a design criteria?
I guess the charity is part of fiction in the H.W. question!
Max.
 

WBahn

Joined Mar 31, 2012
25,230
I agree, too bad about the 'no MCU' a small 8pin footprint micro would do it a cinch.
Strange a charity org that requires it stipulates a design criteria?
Max.
Those are the things that wave the big flags signalling it as an assignment of some kind. The whole charity organization thing is just fluff to give the illusion of it being a "real world" problem. The "no MCU" restriction is almost certainly because using an MCU would render the assignment useless for developing and/or evaluating the knowledge and skills being targeted.
 

MisterBill2

Joined Jan 23, 2018
5,188
If I were teaching a course in the design of digital logic certainly there would not be any MCU devices allowed in any of the tests, because that is no way to gain any proficiency in logic design. If one wants to be a programmer then take programming classes, and don't call yourself an engineer if you are a program writer. The areas are not similar.

I already suggested that the TS can create the needed functions with a very simple arrangement of JK flipflops. An added advantage of that sort of implementation is that it needs no input debouncing. Or maybe it does? But it is an easy logic project no matter what.
 

MaxHeadRoom

Joined Jul 18, 2013
20,000
If I were teaching a course in the design of digital logic certainly there would not be any MCU devices allowed in any of the tests, because that is no way to gain any proficiency in logic design. If one wants to be a programmer then take programming classes, and don't call yourself an engineer if you are a program writer. The areas are not similar.
In spite of the OP's vague description, It has become apparent that a logic device based result was required due to it being apparently a Homework question in this case.
But outside of this, I still maintain in a real world a micro would be the better decision, you obviously exhibit a predilection for logic circuits over micro's, but having gone through the logic era and later embraced the microprocessor, I see the great advantages to cleaner designs and smaller footprints for many answers.
Max.
.
 

djsfantasi

Joined Apr 11, 2010
6,145
IIf one wants to be a programmer then take programming classes, and don't call yourself an engineer if you are a program writer. The areas are not similar.
Just curious as to what you see as dissimilar between an “engineer” and a software engineer. Admittedly, the latter includes programming but additionally includes many engineering skills.

Your statement cannot be argued with as is. A programmer is not an engineer. His title is programmer, and not software engineer. But I detect a further attitude and wanted to dissuade myself that it was there.
 

Thread Starter

electronics123

Joined Feb 22, 2020
35
hi 123,
Welcome to AAC.
Is this a College or School assignment.?
Why is a programmable MCU not allowed.?
E
This is a college assignment
in the design specifications no programmable MCU is not allowed
i have tried my hardest to the do the assignment but i have not been paying attention in school
Could u please help me? I want to excel
 

Thread Starter

electronics123

Joined Feb 22, 2020
35
Just curious as to what you see as dissimilar between an “engineer” and a software engineer. Admittedly, the latter includes programming but additionally includes many engineering skills.

Your statement cannot be argued with as is. A programmer is not an engineer. His title is programmer, and not software engineer. But I detect a further attitude and wanted to dissuade myself that it was there.
I am neither, i am simply a student struggling with electronics subject
 

Thread Starter

electronics123

Joined Feb 22, 2020
35
In spite of the OP's vague description, It has become apparent that a logic device based result was required due to it being apparently a Homework question in this case.
But outside of this, I still maintain in a real world a micro would be the better decision, you obviously exhibit a predilection for logic circuits over micro's, but having gone through the logic era and later embraced the microprocessor, I see the great advantages to cleaner designs and smaller footprints for many answers.
Max.
.
Yes, it is homework, I am a student who takes electronics as a subject however i have been struggling with my project so help would be appreciated
 

Thread Starter

electronics123

Joined Feb 22, 2020
35
If I were teaching a course in the design of digital logic certainly there would not be any MCU devices allowed in any of the tests, because that is no way to gain any proficiency in logic design. If one wants to be a programmer then take programming classes, and don't call yourself an engineer if you are a program writer. The areas are not similar.

I already suggested that the TS can create the needed functions with a very simple arrangement of JK flipflops. An added advantage of that sort of implementation is that it needs no input debouncing. Or maybe it does? But it is an easy logic project no matter what.
I did not call myself an engineer, I am student who is struggling with the subject electronics and i have tried to do the project already but i simply do not understand the subject
 
Top