What logic and digital chips to get ? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 13, 2019, 06:55:31 am
content: I only have a few types of CMOS 4000 chips and old version 7400 series, and not many of any of them. I'll make a full list later. I have some decade counters, cd4026, ripple counters, NAND, AND, OR, hex inverters,I don't have any ADC or DAC chips that I know of, they seem expensive too. I have an Ardino that I'll learn again sooner or later.I have some random collection of MP3 players, radio's, DVD players, TVs, printers, etc that I've scrapped and horded, and so have a handful of small RAM chips, eprom's, processors, multiplexer's, modern CMOS and new 74 series, and whatever all else. Mostly SMD parts.I have a full big set of basic 2 pin crystals for timers. I have copper clad boards for high frequency stuff.So for hobby projects I want to get add some more logic chips and digital stuff in general. So fire away chip names to add to the list ,thanks

author: cur8xgo
author_rank: Regular Contributor
timestamp: June 13, 2019, 03:32:46 pm
content: Quote from: lordvader88 on June 13, 2019, 06:55:31 amAfter a couple decades of collecting logic chips..what I've learned is that ORGANIZING the chips in a way where you know what you have and can browse easily and get the chip you want fast is at least as important as your selection.Chips are cheap and easy to get. But if they are all stuck on anti static foam floating around in a grab bag that you have to spend 15 minutes looking through just to see if you have something..they are all basically useless

author: rstofer
author_rank: Super Contributor
timestamp: June 13, 2019, 04:57:08 pm
content: And in this age, what use are discrete logic chips? I have a BUNCH of chips and haven't used any in years. If I have a logic design, I'll use a CPLD or FPGA. Among other things, this eliminates hours of wire-wrapping. Yes, I have a cut-strip-wrap gun but I haven't used it in many years. Too much Low Scale Integration (LSI) will drive you nuts. Furthermore, I can save room for feature creep without needing board space or sockets.Then there is the low probability that my wire wrapped circuit actually does what it needs to do. Yes, it will do what I told it to do but I didn't necessarily understand the problem. A few lines of HDL will solve that issue!If the design lends itself to a firmware solution, I'll use an Arduino or even an ARM chip.Low level chips just aren't used much unless it is to build a specific Internet project. I might buy what I need but I wouldn't stock any.

author: Zero999
author_rank: Super Contributor
timestamp: June 13, 2019, 07:02:55 pm
content: You don't really need discreet logic nowadays, so there's no point in having a massive stock. There are times when it can be useful though. The 74HCT parts can be useful for translating from 3V to 5V logic, so some 74HCT14 will be handy.

author: bsudbrink
author_rank: Frequent Contributor
timestamp: June 13, 2019, 07:54:36 pm
content: Quote from: cur8xgo on June 13, 2019, 03:32:46 pmAmen brother! I'll add that some electronic list... spreadsheet or just a simple text file makes them more useful still.

author: garethw
author_rank: Regular Contributor
timestamp: June 13, 2019, 08:23:54 pm
content: I bought a few logic gate ICs and TBH I haven’t really used them. However, the Schmitt trigger inverter is a very useful one to have. 74xx14.Sent from my iPhone using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: June 13, 2019, 08:43:51 pm
content: I would suggest only buying the ones you need for a specific project. If you just want to learn in general then get a few NAND gates as you can make any other gate from those. Then some counters, serial and parallel shift registers and a latch.Really though for all this basic logic stuff a simulator like Falstad circuit simulator is about as good as the real deal.

author: bd139
author_rank: Super Contributor
timestamp: June 13, 2019, 08:58:25 pm
content: Honest advice here: DO NOT BUY ANYTHING UNLESS YOU NEED IT. Plan a week ahead. Order just what you need to complete an objective. Don't be afraid to throw discrete components and things in the trash either.I have literally just spent two years clearing out about 100kg of component stock I've collected over the years because I nearly tipped over the line. I'm down to literally nothing now and I buy on demand. I've only kept some weird shit that's virtually impossible to get hold of on demand and some very basic discrete jelly beans. Why:1. It causes mental burden lurking there which is depressing.2. If you're not careful you turn into a crazy batshit hoarder obsessive about holding on to it all. I dropped a DMM off at someone's house near me about 2 years ago I sold on ebay. The guy had drawers on all walls in a 3 bedroom house, including the hallway and part of the kitchen. His wife had left him because of it and he had devoted his life to filing and cataloging crap. Sure he could find a 2W carbon comp 510K resistor or an obscure tube like "that" but there were at least a million components in there that were going to end up in a skip and years of his life gone. He admitted he stopped doing projects because when he got older it became a burden to look after it all.3. You can never find what you want anyway unless you super-organise it and you turn into Mr batshit above.4. You have to catalogue it all which becomes a consistency issue and a chore.5. You probably aren't going to use all the items so it's a false economy plus if you don't buy 2000 of each value shitty hair legged resistors from China, you can afford a few good ones. Same with ICs etc. I used to shudder at paying 10 GBP for an IC but if I hadn't got 11 tubes of 74ls04's I could afford to just buy the damn thing and shrug it off.Find a cheap supplier who does small quantities, write up what you need, buy the parts, do it and then clean it away.Edit: apologies for sounding like a crazy person

author: cur8xgo
author_rank: Regular Contributor
timestamp: June 13, 2019, 09:38:10 pm
content: Quote from: bd139 on June 13, 2019, 08:58:25 pmWhat you say here is true..and many, many times, I have seen this hoarding of components first hand. Nothing more depressing than a filthy garage filled with dusty parts that never got used in anything at an estate sale. Do NOT be that guy.That said, after years of working both professionally and on my own projects in electronics, I would definitely have been crippled in the following activities without a reasonable stock of parts:-prototyping-repairing-experimenting/learningI have limited myself to a certain fixed volume of space in which I can store engineering objects, and this has worked okay. I've also sub-limited that space into fixed volumes for things like resistors, switches, wire, vectorboard, logic IC's, transistors, etc..all the "categories" have their own fixed box. I have not collected more than these fixed areas and I do like to throw stuff away when possible.Looking back, having a WIDE assortment of the following has paid off and I use these parts the most from my immediate stock:-through hole and SMT resistors and capacitors-through hole potentiometers-transistors (bipolar and mosfets most importantly, through hole and SOT-23)-diodes (low Vf schottkys, small and big power silicon, sot23)Having SOME of the following has been important, although a wide assortment was not needed-basic logic like NAND and schmitt trigger inverters, CMOS wide supply range is very handy-switches (toggle, pushbutton, AC capabale)-relays-voltage regulators-LED's and photodiodes-inductors and transformersAnd the following have proven over the years to not really be that important:-microcontrollers/processors (usually projects involving these need a specific part number and/or package and having some random one on hand isnt useful)-obscure logic-uncommon transistors-smt parts that would not be useful for quick usage because of extremely small size or dense footprint (tssop parts are not fun to hand solder, SO or bigger is still useful though)-displays (projects using a display arent in a rush and choosing a specific display is probably more efficient)

author: hamster_nz
author_rank: Super Contributor
timestamp: June 13, 2019, 09:58:09 pm
content: I've added the 74xxx page from the latest Jaycar Electronics catalogue - have a look through and see what you might use.However.... Even though I can walk there at lunchtime I have never purchased any of these. Every bare IC I have purchased in the last 5 years has been specialized - e.g. a low resistance MOSFETs, audio DAC, 24-bit ADC, CH340 USB serial bridge, special LDO regulators... they have also all been exclusively SMD, as through hole is so not worth it.If starting again and wanting to breadboard with I would get some SMD parts and put them on DIP carriers. That way I have parts that I can use should my breadboard turn into an actual PCB.If you really pushed me, I would say stick to 74LS series, get some of the basic 2-input logic gates, some hex NOTs and buffers, a few counters and a few different sort of Flip-flops. As everybody else says you will never really use them once you have learnt what they do, so don't get too many!PS. Companies used to build supercomputer CPUs using just three different chip types - NAND gates, Registers and memory. Seehttps://www.cs.auckland.ac.nz/courses/compsci703s1c/archive/2008/resources/Russell.pdf

author: bd139
author_rank: Super Contributor
timestamp: June 13, 2019, 10:00:21 pm
content: You can build anything with 74LS00's and they're dirt cheap on Tayda (think they are hitachi).

author: bsudbrink
author_rank: Frequent Contributor
timestamp: June 13, 2019, 10:07:03 pm
content: I should note, I collect/repair/restore "vintage" computers. To me, "vintage" is 1970 to 1981. So I do "hoard" chips and other components from that time period. Gathering lots of TTL logic is probably not necessary for people without that or similar interests.

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 14, 2019, 12:04:40 am
content: Likewise here, but my hobby is related to glass electronics ( vacuum and gas filled tubes).Since these are already in short supply and some devices are essentially non existent, the temptation is VERY STRONG to hoard some. I have to think really hard whether it is actually feasible that I will use them in a reasonable timeframe.But if you are contemplating LSI ICs, please follow the recommendations above, before it’s too late and you get “The Disease.”

author: 0culus
author_rank: Super Contributor
timestamp: June 14, 2019, 12:12:27 am
content: YMMV, but an argument for keeping areasonablestock of parts other than for repairs is that you can throw together prototypes on a whim. I am kind of that way...I'll decide to try some circuit on a lark and it can kill the muse if I don't have the right part on hand and have to wait for an order. Definitely don't have a garageful of stuff you'll never use though! Small quantities....

author: wilfred
author_rank: Super Contributor
timestamp: June 14, 2019, 12:52:59 am
content: If you have to buy one part you may as well buy all of them. I always struggle to get to the free postage threshhold so that's the way to build a stockpile of parts. Buy spares of what you are using.You're not going to have everything you need and you're not going to use everything you buy. That has to be a fundamental law of the universe.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 14, 2019, 01:28:25 am
content: No point in storing jelly bean parts beyond what you need for the current project. I threw away lots of useless parts and shrank down from three to one storage cabinet.I only keep 74LS and small DRAMs for my Commodore stuff. That's it.Also esd foam has a finite life span. Some of the crap I had for 10 - 20 years also became useless as the foam disintegrated on the pins and corroded them.Tells me I didn't need those parts, except as a trophy. So out they go!

author: Dabbot
author_rank: Regular Contributor
timestamp: June 14, 2019, 02:37:30 am
content: You might find a small collection of shift registers and (de)multiplexers of use to expand the I/O of your microcontroller:74HC151 - 8-line to 1-line data selector / multiplexer74HC154 - 4 to 16-line decoder / demultiplexer74HC164 - 8-bit serial in parallel out shift register74HC165 - 8-bit parallel in serial out shift register74HC594 - 8-bit serial in parallel out shift register with output registers74HC595 - 8-bit serial in parallel out shift register with tri-state outputsThe serial in parallel out shift registers are a popular choice for multiplexing 7-digit / dot matrix displays.

author: Jwillis
author_rank: Super Contributor
timestamp: June 14, 2019, 07:54:00 am
content: You can get assorted 4000 series and 74HCxx series kits from Amazon or Ebay fairly inexpensively .They can range from a few bucks to around 30 dollars and have the most used popular chips in the kits.And come in either TTL or CMOS for both series.

author: brabus
author_rank: Frequent Contributor
timestamp: June 14, 2019, 09:33:10 am
content: I used to hoard components as well, until I started doing this thing once a year: The Giveaway!I post photos of stocks of components (a bunch of OpAmps, power transistors, passives, transformers, you name it) on my local forum, literally giving it all away to students/makers/tinkerers in my area.That damn BC547 makes a lot more sense sparkling fire on a breadboard instead of aging in my drawer!People are usually extremely grateful for that, and my garage looks clean again. :-)

author: HB9EVI
author_rank: Frequent Contributor
timestamp: June 14, 2019, 11:17:24 am
content: I have half an assortment box with 74HC/T parts; most commonly I have need for 74HC04 and 74HC74, but also for others when I resume working on my Z80 board from time to time.I still like working with logic chip out of convenience.Since I like prototyping randomly at any possible electronic topic - computer-, ham- or audio related, I have a proper stock of jellybean components and some more particular chips; certainly what is used most is the storage box with 0805 Cs and Rs - which I prefer over wired components.

author: KL27x
author_rank: Super Contributor
timestamp: June 14, 2019, 07:57:06 pm
content: Keep in mind, most modern electronic components have very little inherent value. The reason the large distributors can sell the parts for what pittance they do is because they have and can deliver ALL of them on demand. They have a web store what lets you find them and also show you lead times, number in inventory.Buying parts you don't need is entropy. You are destroying value. You're letting the air out of the tank. You're taking these parts from a distributor who has everything sorted and stored and ready to go in a way that gives it value to other people and companies. And you're putting them into a home lab. Why? Perhaps because you learned one way to skin one particular cat, and now you're stocking up on stuff with some vague idea that you will encounter a lot of these specific cats what need skinning, that you will actually be interested in skinning them, but that you need the ability to skin them TODAY without waiting a few days.That super low per that Digikey sells the part for at 10,000+ units? That includes some margin for them. Remove that margin. When the parts are sitting in your house, they are worth less than that. A lot less. You're paying Digikey for the value the company adds through their own effort and payroll and infrastructure. And they do that more efficiently than you ever will.You're never gonna have enough of everything. You can't reach a cricital mass where you never have to order a random part. Well, not until you run your own component store complete with several employees or you are a hoarder getting eviction notices. In either case, you won't have time to use your components.

author: typematrix
author_rank: Contributor
timestamp: June 14, 2019, 10:01:30 pm
content: Re hoarding or bulk buyingThere is great temptation to buy in bulk and buy kits and things,eg "When it is one buck for one piece or 2 bucks for 5 pieces"and as a result we end up with too many components.I usually gather the excess once a year and sell it off as a batch/kit on local ebay. Its very difficult to sell small individual second parts, and time consuming and annoying unless its something like an arduino or module.Once you buy something, thats it, make something out of it or its going in rubbish bin or rotting in a parts locker.You can sell it again but not for muchI was thinking that a website that allows electronic hobbyist to buy and sell and swap parts with each otherwould be a real cool idea like bricklink for lego enthusiasts.https://www.bricklink.com/catalogTree.asp?itemType=P&itemBrand=1000

author: wilfred
author_rank: Super Contributor
timestamp: June 15, 2019, 01:11:51 am
content: Quote from: KL27x on June 14, 2019, 07:57:06 pmA very clinical analysis. But I specifically want to comment on "vague idea". That's what I refer to a "dreams". We all have them and we all need them. The key is to arrive at a point of balance where you stoke your dreams but let go of the vague ideas.Thats not at all easy to do which is why so many of us (me included) accumulate parts. It is something different to order 5 of a part you are using because you might get a dud or zap one or whatever.I can't resist "free shipping".

author: james_s
author_rank: Super Contributor
timestamp: June 15, 2019, 01:21:49 am
content: It really depends on the part. If it's something like a microcontroller, IC socket, trimpot, LED, that sort of thing then buying extra often makes sense. The same part is likely to find use in any number of projects, some items like LEDs and voltage regulators will be used in almost every project. Common resistor values like 1k, 4.7k, 10k, etc are handy to have on hand, likewise some common values of electrolytic capacitors.Doesn't make sense to buy a lot of excess parts of more esoteric nature but quite often I'm able to put something together using only parts I have on hand, if not the final project then at least a prototype or proof of concept. I find it invaluable to have a stock of parts, but that doesn't mean amassing a huge hoard is a good idea.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 18, 2019, 12:11:55 am
content: Simple logic chips are indeed hardly worth hoarding.About 30 years ago I desoldered several thousand of them, and nicely sorted them and put them in drawers.They're still there.I may have used a handfull of them over those years.Nowaday's you're much better off with getting a few nice microcontrollers or maybe even FPGA's.uC's are so much rmore versatile.

author: KL27x
author_rank: Super Contributor
timestamp: June 18, 2019, 12:18:38 am
content: QuoteI could say the same thing about microcontrollers, only change 30 years ago to 15. We get new flavors every now and then, and the old stuff just becomes obsolete. When you have 3, and that's all you have, you might find some cute use for them. You might think if you have a thousand, it will be even more useful. But if you have a project where you can use a thousand.... how do you know it will stop there? Then you are stuck having to port the project or continue using an obsolete part which might be overpriced or unreliable to source.

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 18, 2019, 12:26:43 am
content: Think how many old projects that a hobbyist might make that still call for CMOS4000 chips, that's why I want a few more around

author: james_s
author_rank: Super Contributor
timestamp: June 18, 2019, 04:25:10 pm
content: Quote from: KL27x on June 18, 2019, 12:18:38 amI wouldn't recommend buying 1,000 of any part unless you're using large numbers of them, but having 10-20 microcontrollers around is handy. In a sense they do get obsolete but in many cases that doesn't really matter. Just last year I used a ATTINY13 I'd had in a drawer for years, it's an old part that is probably considered obsolete by most but it's just as useful as it ever was and for what I needed it was more than adequate. I've still got a pile of AT90S2313 AVRs I got close to 20 years ago when I was using them in projects, I still use one of those now and then too, if not for the fact that they require an external crystal or resonator I'd use them more often. I've built digital clocks, programmable controllers, traffic light and pedestrian crossing sign controllers and other various stuff. There's a lot you can still do with 2k of memory.

author: ledtester
author_rank: Super Contributor
timestamp: June 28, 2019, 02:35:43 am
content: I'd consider getting a couple of CD4007s to play around with. Over time I've seen a bunch of references to it in articles and projects. Just a few examples...-http://www.learningelectronics.net/VA3AVR/tutorial/xtor/xtor10/xtor10.html-https://wiki.analog.com/university/courses/electronics/electronics-lab-28- Articles by Ray Marsten appearing in Nuts and VoltsThe CD4007 gives you pairs of NMOS/PMOS transistors which are well-matched and that's important for cerain analog amplifier circuits.

author: jfiresto
author_rank: Frequent Contributor
timestamp: June 28, 2019, 07:19:19 am
content: Quote from: james_s on June 18, 2019, 04:25:10 pmThe ATiny13 (now ATtiny13A) is still quite useful. I went through the current AVR catalog a few months ago, and it and the ATtiny24 were the first, smallest parts that would address a design: the ATtiny24, directly, and the ATtiny13A, with a single gate, which the design needed, anyway, as a "coulomb buffer". All the rest had a least one grievous gotcha, each, that ruled them out. In this case, the ATiny13 improved on both its predecessors and successors.