Starter kit list for logic gates?

Discussion in 'The Projects Forum' started by peskywinnets, Feb 18, 2009.

  1. peskywinnets

    Thread Starter Active Member

    Jan 19, 2009

    I'm wanting to build a little circuit, where I can preset the number of turns for a motor to turn & when the pulses received from a tach pulses from that motor, the motor stops. (this is an overly simplistic explanation, as I envisage there being several counters all working of the same tach feed...also up to 8 pulses per revolution).

    Now I'm new to logic gates (ok, so not completely I know the basic truth tables of the various type of main gates!), & I want to put in an order for some parts.

    i know I'll likely ultimately need a BCD chip or two & perhaps a decoder, but this project aside, I was wondering if anyone had a good 'stater' list of the more common logic chips (ie by device number)...this would help me greatly in formulating my first parts order!

    for example

    Logic Gate Starter kit...

    4000 Quad Nand
    4516 BCD
    4028 Decoder

    etc etc.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    This is harder than it might seem. Not all the gates are still to be found, or are evenly stocked by a distributor. 4000 CMOS is easy to work with, and probably a good choice.

    I work out of a couple of old print logic manuals, but have learned to check availability before proceeding with a design.

    It's also hard to guess as to the most handy gates to have on hand - 4081 quad dual input AND gates, or 4082 triple three input AND gates?

    I would get some having interesting functions to experiment with, and order others as you need for a design.

    A good breadboard could be very useful, but the sheer number of wires gets confusing. Any number of people will also drop in and tell you to just select a microprocessor and get it over with. Any level of complexity that might require 39 logic IC's can be done with a nearly invisible AtTiny uC.
  3. KL7AJ

    AAC Fanatic!

    Nov 4, 2008

    Newark still stocks 7400 series logic...and presumably several others do, too.
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    Yes, Digi, Mouser, Jameco all stock logic. The problem is not that, but that some types in each family have simply gone away. 4000 CMOS seems to have lost the fewest members of the family. Both Digi and Mouse carry it, mostly made by TI.
  5. BillO

    Distinguished Member

    Nov 24, 2008
    Are you stuck with a given type of motor? Depending on the precision you need, it seems a stepping motor and a PIC may be the way to address this if you have the opportunity to start from scratch.

    I'd be tempted to go with a PIC or some other micro-controller anyway.

    Doing this with counters and gates will be a bit of a project and if you are not using a stepper, would not be that precise anyway. Especially if the motor is relatively high speed and/or the load varies.

    If precision in not an huge issue you could do it with a one-shot, a large low leakage capacitor (tantalum), a mosfet-input comparator and a handful of passive components.
  6. peskywinnets

    Thread Starter Active Member

    Jan 19, 2009
    I am driving a stepper. (from tach pulses taken off a non stepper).

    What the end goal is, is an automatic coil winder. Imagine a small bit of steel bar (5mm diameter) in a chuck being turned by a motor. Onto this bar, fine wire will be wound. I know the coil wire is 0.15mm in diameter, so I want to turn a stepper turning a thread rod, over which the coil wire feeds onto the bar by the same amount for each turn of the motor holding the bar. Therefore one turn of the motor (holding the bar) sends tach pulses to a logic counter circuit & ultimately the threaded rod turns 0.15mm. The direction of stepper motor will reverse at the chosen coil extremeties.

    I want to learn logic gates first....then PIC programming. The logic bit, will be a 'front end' added to this circuit... (explanation here... )

    What I really seek first is a good starter logic IC list to order up.
    Last edited: Feb 19, 2009
  7. SgtWookie


    Jul 17, 2007
    Arguably, a 4093 quad NAND Schmitt trigger is one of the most versatile CMOS IC's. Using just NAND gates, you can build any other logic gate, including simple logic inverters (NOT function).
    NOR gates are nearly as useful, but I don't offhand know of a CMOS version that's also a Schmitt trigger.

    Logic IC's have fallen into disfavor due to microcontrollers; the latter are very inexpensive nowadays, and it doesn't require a lot of fancy hardware to program them anymore.

    With logic IC's (74xx, 4000 series, etc.) you'll have to do a lot of re-wiring in order to change the function of a given circuit. With a uC, all you have to do is reprogram it. You can replace dozens (even hundreds) of logic ICs with a single uC.
  8. Wendy


    Mar 24, 2008
    Don't forget the 4001 (2 input quad nor), it is as basic as it can get.

    4049 - Hex Invertors

    4027 - Dual JK S/R Flip Flop

    Diode gates can do quite a bit too, for odd input numbers.

    Download my PaintCAD from my blog and you can get a pinout sheet of some of my other favorite. My blog can be accessed on the blue number under my name on the upper right hand corner of this post.

    Sam Electronic Circuits is also a good site for looking up more common datasheets.
  9. peskywinnets

    Thread Starter Active Member

    Jan 19, 2009
    Apologies for the delay, but thanks to you all for taking the time to reply & help me out.

    Many thanks.