Essential electronis components for beginners - Page 1
Forum section: electronics / beginners

author: robsims
author_rank: Frequent Contributor
timestamp: July 27, 2022, 08:18:22 pm
content: Hi, i already have an electronic component kit with resistors, led's, capacitors, inductors, potmeters, transistors, diodes etc.Are these good ic's to have or are they outdatedhttps://www.amazon.com/HUAREW-Darlington-Phototcoupler-ULN2803APG-Assortment/dp/B08Y8BMM4M/ref=sr_1_2_sspa?keywords=op+amp+kit&qid=1654210645&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFZV0dOMFBDODZETDAmZW5jcnlwdGVkSWQ9QTAzMjg0MDRNNDVBMkRVRVNSTk8mZW5jcnlwdGVkQWRJZD1BMTAxNjc1MTIwNDdNQ1JBQzBVMTMmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl#customerReviewsMany thanks

author: rstofer
author_rank: Super Contributor
timestamp: July 27, 2022, 09:12:11 pm
content: Many of the projects on the Internet will use these devices or they can substitute in. It's nice to get a variety and a bin box to keep them in. They're only about 14 cents each!If you buy other parts, buy more than you need for the immediate project. Need a particular op amp? Buy 10...

author: robsims
author_rank: Frequent Contributor
timestamp: July 27, 2022, 09:28:20 pm
content: Thank you rstofer. So i will get them

author: John B
author_rank: Frequent Contributor
timestamp: July 27, 2022, 09:51:10 pm
content: Have we not learned that these ICs are probably all fake and the all the op-amps are probably the same fake chip? Especially things like the NE5532, I would not expect that to be real.

author: rstofer
author_rank: Super Contributor
timestamp: July 27, 2022, 10:21:59 pm
content: DigiKey has over 3000 NE5532P in stock at around #0.76/each and over 3000 NE5532AP for around $1.32. Apparently the device is still current and available from primary distributors.Could they be fakes from Amazon? Sure! Maybe they are, maybe they're not.

author: robsims
author_rank: Frequent Contributor
timestamp: July 28, 2022, 01:24:48 am
content: But where or how can i get real components, not fake's. I'm a beginner so i need to know

author: SmallCog
author_rank: Frequent Contributor
timestamp: July 28, 2022, 01:45:31 am
content: For "Real" components order them from suppliers such as Element 14 and RS Components

author: onsenwombat
author_rank: Contributor
timestamp: July 28, 2022, 01:49:45 am
content: Quote from: robsims on July 28, 2022, 01:24:48 amSimplest answer: authorized distributors.But what is an authorized distributor? The mammoths of vendors like Digikey and Mouser are surely authorized (enough) and trustworthy. Another way is to search your gizmo in Octopart and see which vendors are flagged as authorized there.I'm not that much into that market, so very likely there's perfectly legit vendors that are not authorized, or don't show as such in Octopart search, but now we're stepping out of the "how can a beginner know how to get real components" territory.Basic rule of thumb: No-name vendors in whatever Alibaba or eBay, no matter how much positive feedback (easily fabricated) they have, do not act surprised if you get total dogshit from them - think of it more as a baseline.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 28, 2022, 02:01:11 pm
content: Sites like amazon, ebay, aliexpress are nice to get assortment boxes such as 600 transistors for EUR10 or books with several thousand SMT resistors, but they can't be trusted in any way.If you buy a bunch of TO220 power MOSfets that are supposed to be able to handle 50A, then don't be surprised they catch fire above 10A.But for things like your first experiments and building circuits on breadboards things like that do not matter much and are mostly acceptable.Apart from that, about the only Chinese supplier I have some trust in is LCSC.

author: robsims
author_rank: Frequent Contributor
timestamp: July 28, 2022, 04:22:06 pm
content: As a beginner i dont know which opamps to buy. Can i get a list from someone so i can order them at a reputable company like digikey

author: james_s
author_rank: Super Contributor
timestamp: July 28, 2022, 05:32:10 pm
content: It's usually best to find a project you want to build, then buy the parts needed to build that project. Things like resistors, capacitors and LEDs are handy to have assortments of but buying random collections of ICs generally leads to having a bunch of ICs you never use.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 28, 2022, 05:53:40 pm
content: OPA991 or better OPA2991. Very versatile opamp.TL431/TLV431LM31778L058-bit MCU of your choice (ATmega?)BC547/BC557BC807/BC817NE555

author: rstofer
author_rank: Super Contributor
timestamp: July 28, 2022, 06:04:05 pm
content: One of the more common op amps for older projects is the uA741, first released in 1968. They are excellent for analog computing as in the Comdyna GP-6 (of which I have 2). Still current manufacture after 54 years! Mouser has a bunch of stock for SOIC package with the DIP package on order. DigiKey has 52,000 of the DIP version in stock at about $0.50 each, qty 1. The tin can version is a little harder to find.https://www.ti.com/lit/ds/symlink/ua741.pdfhttps://oldcomputermuseum.com/comdyna_gp6.htmlFor most of the older projects, you will need +15V and -15V power supplies. Like this:https://www.jameco.com/z/PD-2515-MEAN-WELL-Power-Supply-Dual-Output-Open-Frame-15V-1A-Negative-15V-1A-24W_2100857.htmlYou can also use a dual or triple output bench supply.

author: robsims
author_rank: Frequent Contributor
timestamp: July 29, 2022, 12:31:19 am
content: Thanks for all the information. i already have some projects in mind, i am going to work on. I will make a list of all the parts mentioned in this thread and then buy them.One of the projects is a low mains AC cut off circuit. If mains AC voltage drops to 100 Volts the circuit has to cutoff the refrigerator from mains AC. So if mains AC voltage if 75 volt for example it will not damage the refrigerator.

author: mindcrime
author_rank: Unknown
timestamp: July 29, 2022, 03:20:18 am
content: Quote from: Max2018 on July 28, 2022, 08:34:34 pmI'd posit that there are still lots of uses for a number of 74xx chips. Some times you just need a simple AND or OR gate and don't need the complexity of a micro-controller. There's a lot to be said for a 7404 (inverter / NOT gate), 7408 (AND gate), 7432 (OR gate), etc. And the NAND, NOR and XOR operations can be handy from time to time.Latches and flip-flops (whether 7400 or not) can be handy as well.

author: Warhawk
author_rank: Frequent Contributor
timestamp: August 08, 2022, 12:25:22 pm
content: Quote from: Max2018 on July 28, 2022, 08:34:34 pmAlthough I am old-fashioned, some parts have nowadays way better and often cheaper alternatives. The AMS-1117-5.0 device requires relatively large output cap (alu/tantalum]. It requires also a minimum load of up to 10mA. I used the 117 series many times but it is not my go-to LDO. By the MCP34063 you probably meant the MC34063 device. Yup... that thing is classic but so outdated. I too used it many times. Again, I would not touch it anymore unless a THT part is necessary.Have a look at the opamp I mentioned. It is r2r input/output opamp that can drive a quite high load. This means it can drive, for example, a power transistor directly. Quite nice. SOIC to DIP adapters are cheap. It can also work open-loop (comparator) which many opamps can't (or should not).OP: Have a look at the book "The art of electronics". It comes with companion books and lab exercises. I think DigiKey offered a whole parts kit. That's probably the best place to start.PS: It also made me proud that a picture of one of my designs made it to the X-chapters book... What a good day it was when I found out.

author: ledtester
author_rank: Super Contributor
timestamp: August 08, 2022, 02:55:26 pm
content: Quote from: Warhawk on July 28, 2022, 05:53:40 pmI actually find building timer circuits with schmitt trigger logic gates a lot easier. At least the circuit is a lot easier to remember.I think you'll find the CD4093 and CD40106 handy to have around. For some ideas on what you can do with the CD4093 check out the table of contents of this book or just google "cd4093 circuits":https://www.amazon.com/4093-IC-Circuit-Sourcebook-Components-ebook/dp/B06X6G5T3C

author: rooppoorali
author_rank: Regular Contributor
timestamp: August 10, 2022, 03:54:50 am
content: I can see that the kit is currently unavailable. However, these are some common ICs. These are definitely helpful. Also buy a breadboard and a digital multimeter if you already have not.

author: JohanH
author_rank: Frequent Contributor
timestamp: August 10, 2022, 07:10:30 am
content: I've used OPA991, but now I need a dual OPA2991IDR (SOIC). They are out of stock and no inventory anywhere. Well, have to find an alternative then.

author: cellularmitosis
author_rank: Unknown
timestamp: August 10, 2022, 07:38:14 pm
content: One approach which can be useful for a beginner when trying to identify what the "jellybean" parts are, is to look at what the smaller distributors offer.For example, look athttps://www.taydaelectronics.com/orhttps://www.futurlec.com/Components.shtmlWhen starting out, it is easy to be overwhelmed by the near infinite choices available at digikey or mouser. Looking at a smaller selection to start with, and then reading some of those datasheets is a great way to start getting your feet wet and building a base of understanding.When designing a circuit, I'll sometimes see if its possible to build the entire circuit using only parts from tayda, for example.(Also, these days, the resistors from tayda are pretty nice. The leads are thick enough to be breadboard-friendly and feel like copper when they bend. If you go with the cheapest ebay resistor assortment, you'll end up with suuuuper thin leads which are probably steel, and are annoying to deal with).Side note: I also used to recommend stocking up on 2N3904 / 2N3906, but I've since realized that PN2222A / PN2907A are basically drop in replacements which handle more current.

author: cellularmitosis
author_rank: Unknown
timestamp: August 10, 2022, 07:42:00 pm
content: Also, one thing which I have been bitten by multiple times is trying to buy cheap breadboards. I don't know what the deal is, but cheap breadboards are notorious for having a ridiculously high insertion force. As in, you literally can't insert a resistor because the leads simply bend in half when you try to push it in. I can only conclude that the manufacturers aren't actually testing their product.At 9 bucks a pop, the BB830 isn't cheap, but it is the only breadboard I will buy from now on.

author: cellularmitosis
author_rank: Unknown
timestamp: August 10, 2022, 07:53:48 pm
content: Another way to approach the task of "what should I stock up on so that I can prototype with parts on-hand?" is to look at the range of what's needed, and see if you can pick just a few parts which reasonably span that range.One example is wiring ("which gauges of wire should I buy?"). If you look at an engineering table of gauge vs resistance per foot, you'll notice a nice little symmetry of 22AWG, 16AWG and 10AWG are each four times more conductive than the last. Just getting these three sizes of wire will cover your light / medium / heavy duty current requirements well. Even the resistance is easy to remember, 16mOhm, 4mOhm, and 1mOhm per foot.For the 22AWG, just order some solid/single-strand CAT5 cable and you'll have a large supply of nice, breadboard friendly twisted pairs. Having the pairs twisted also does a great job of minimizing EMI pickup for sensitive measurements.You can take a similar approach for BJT's, MOSFETs, resistor values (e12 or maybe even just e6), capacitor values (e3 is probably fine! 10, 22, 47), etc.

author: cellularmitosis
author_rank: Unknown
timestamp: August 10, 2022, 08:04:42 pm
content: And if you can't afford those fancy component drawers for resistors, etc, you can get by with a plastic storage box and some large and small plastics bags.Use a large plastic bag for each decade, with a small plastic bag inside for each value. This turned out to be quicker / easier to use than I would have initially thought.Note: don't store MOSFETs in plastic (unless it is anti-static coated).