Three questions :)

Discussion in 'General Electronics Chat' started by iPromise, Aug 12, 2013.

  1. iPromise

    Thread Starter New Member

    Aug 11, 2013
    Hey guys,

    I think I can say i've achieved a high degree of understanding with computer programming. I am now coding kernel drivers and other types of high-end software.

    But I would like to my skills to good use.

    I want to start learning about digital circuits so I am able to create my own circuits, and then put code in them. For instance, I want to eventually start off by creating my own clock, then calculator and so forth.

    I remember my computer engineering teacher telling me that towards the end of the six month course (in high school) they created logic gates from scratch and made a basic device for the game rock, paper scissors.

    I thought that was cool but I was curious as to how they managed to be able to grasp enough knowledge to create their own circuit from scratch and create a basic electronic device in just six months. I posted a few questions about transistors and logic gates and I was told that it takes many months, even years to be able to understand it to that degree.

    So my first question is what type of transistors can you think of that my teacher had his students create to assemble their own logic gates and how were they able to understand how to create that within a short duration?

    My second question is does this faculty (understanding and creating digital circuits on your own/in companies) all fall under electrical engineering?

    My final question is where do you write your computer code in the digital circuit you've assembled and how is it written? How does the circuit remember your code that you've written to it?
  2. LDC3

    Active Member

    Apr 27, 2013
    :eek: You don't need to post the same thing twice.
  3. iPromise

    Thread Starter New Member

    Aug 11, 2013
    sorry! my internet was lagging and I didn't see the topic there so I thought I didn't have permission to post here yet because of my low post count.
  4. BillB3857

    AAC Fanatic!

    Feb 28, 2009
    If you go back many, many years, most logic functions (gates) were simply resistors and diodes. If you needed an inversion, you put in a vacuum tube triode. A Flip-Flop was two vacuum tube inverters that were cross coupled. It is amazing the things that were accomplished with just those elements.
  5. MrChips


    Oct 2, 2009
    You can create logic gates using an ordinary NPN transistor and a bunch of resistors and diodes. It would be very difficult to make your own transistor. You simply go out and buy a whole bunch of NPN transistors.

    You can make a few gates with transistors. It would be very tedious and time consuming to build anything complex using transistors. It is very doable if you move on to using gates on an IC package.

    You can learn to do this within two months of study, let's say 4 hours a week for 8 weeks = 32 hours of classroom and laboratory work.

    You can learn about digital circuits in many places. In college or university it may be taught under:

    General Science
    Computer Science
    Computer Engineering
    Electrical Engineering

    Program code is normally stored in memory which could be one of many different forms:

    SRAM - static memory
    ROM - read only memory
    PROM - programmable read only memory
    EPROM - erasable programmable read only memory
    Flash memory
    Memory stick/card
    Magnetic memory (removable or fixed drive)

    For what you have in mind, program code is stored in Flash memory.

    If you are thinking of a hardwired circuit, there is no program code. It is like building a Rube Goldberg Machine - pull on string A and paddle B moves to kick dog C in the rear end.
    iPromise likes this.
  6. Brownout

    Well-Known Member

    Jan 10, 2012
    #1: More than likely, they used digital integrated circuits and not transistors. Nobody uses transistors for digital design anymore, unless it's a purely acedemic exercise.

    #2: Yes.

    #3: Not to be condescending, but if you design your circuit using digital logic, there is no program to write. However, if you use a micro controller to implement your functions, then you write code for which ever micro you're using, compile and download it to your device.

    Regular digital circuits don't require any programming.
  7. iPromise

    Thread Starter New Member

    Aug 11, 2013

    ^ you nailed it :)

    thanks !