How to find components you do not even know exist - Page 1
Forum section: electronics / beginners

author: dcbrown73
author_rank: Regular Contributor
timestamp: September 20, 2017, 11:26:55 pm
content: I'm new and learning to build circuits and electronics, so bare with me if this is a stupid question.So, how do you find components that fit your need when you may not even know if they exist?Or even more so. Say you know of a component that will do the job, but there are others that maybe better suited than the one you already know will do the job. (though as said in a far less efficient way)Looking at Digikey or Mousers websites can be overwhelming and many times I'm not even completely sure of of what the parts I'm looking at are.Is this just a time+experience thing or is there some trick to help make component hunting easier.As a bonus question, I'm buying parts as I need them and I've bought small packages of common components (resisters, diodes, caps, etc) Though when it comes to other devices there are so many options. I mean I know LM317 and LM386, etc. Though I was thinking of keeping a small supply of many others, but I have no idea what the most common are. It sucks when everytime I come up with something I want to build for learning or just something I came up with. I have to order and wait for the components to come in.Anyhow, any insight would be great.Thanks,Dave

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 20, 2017, 11:30:50 pm
content: Paper catalogues are good for this.Once you know roughly what you want, parametric search can narrow down the options pretty quickly. Sometimes when presented with a huge list, simply clicking "sort by price" will get you pretty close to what you want.If it's something slightly oddball, a few well-crafted Google searches can at least provide a starting point.

author: Brumby
author_rank: Unknown
timestamp: September 21, 2017, 02:28:31 am
content: For the "general knowledge" method, I agree with the paper catalogue approach. Just grab one and have a flick through. You are bound to come across things you've never seen before and these can lead you into an Aladdin's Cave of bits and pieces.As for solutions to a specific need - you could pretend it already exists and go looking for it. I did this recently for a voltage regulator for a very specific need with low dropout and physical size constraints. I didn't really have much of an appreciation of the range of regulators available past the LM317 and 78XX families - but I foundexactlywhat I wanted on RS for less than $1.20 each.I just started out with a couple of keywords in a Google search and after a couple of iterations, found the family of devices that had the one I was after.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: September 21, 2017, 07:54:28 am
content: A thing that one needs to accept (and this can be really hard) is that you simply can't reach perfection, and that there will always be a better solution out there.As you say, this is a time/experience thing. Of course, it can help to ask around a bit if you are unsure - on forums, IRC, colleagues, etc. As others have suggested, paper catalogues can be great. Another usefull resource can be the product marketing books from IC companies. More than once have I gone "oh, that is a thing?" when scrolling through the analog devices or Linear tech (I guess they are the same thing now) marketing emails.As for your final problem:Quote from: dcbrown73 on September 20, 2017, 11:26:55 pmThis can be hard. There are a few options here:In general, you can sometimes use "less ideal" components for a first proof-of-concept while you wait for components to arrive: If I need to verify if say a current measurement circuit works, I can just build it up with low-precision opamps and see what gives. This will give me an idea of stuff while I wait for the fancy precision parts to arrive. So some general RIRO opamps can always be usefull, and they don't have to be super-expensive to work in a proof-of-concept.A second thing is that most places still have some form of physical store you can run to. I have a small supply in my university (though they sell only shitty opamps, no precision or riro ones). Additionally, there is a component store where I can always go check out to see if they have something similar to what I seek in stock. They tend to have most components that aren't to exotic, and again, when prototyping the exact part is generally not vital in first versions. Ofcourse, they are a bit more expensive than ordering in bulk from say RS or Farnell, but I have them when I leave the store, and I don't have to wait.Another thing to consider is just ordering 5 or 10 of whatever part you order (if it's not to expensive) if you think it might be usefull in the future. I tend to do this with diodes and rectifiers, basic logic stuff, etc.And a final thing that can be interesting: Look at auction sales of old labs, schools, etc. Most of my parts are from a few bulk purchases when companies or labs closed or such. For just 90 bucks I got myself more than 500 euros worth of precision opamps (and that is just by going through about a fifth of the components I got, still sorting it).

author: BenKenobi
author_rank: Regular Contributor
timestamp: September 21, 2017, 11:42:07 am
content: The challenge I think that the OP is facing is similar to the one faced in software design using '3rd Party' API's (basically libraries of pre written code). The coder needs something to happen and writes code for it, somebody then says why didn't you use this API for that, or he may find an API but then there may be a more efficient API or even a better way to achieve the same result. I think that only experience can really answer such questions. A novice like myself for instance could look through the library or catalogues for the rest of my days and still miss the solution simply because of a description or documentation that wasn't really clear - and how long does this process take. Then there is selecting the good versus the bad - the genuine versus the fake. In my time playing around with Arduino and Raspberry Pi I've found that the component world is a nightmare, you spend a couple of weeks building a circuit only to find that the same thing exists in a single IC ...I followed Dave's build a lab PSU and how he figures out 'well I can get rid of that and use one of these' type scenarios can only come from experience because you have to know that 'one of these' even exists.I understand the OP's question but I don't think that a simple answer exists for it - forums like this are the best search engine, so instead of formulating a google search why not explain what you want to achieve and post it here, then see what solutions pop up, I guarantee you will get some that you hadn't even considered, the amount of experience on here seems boundless.

author: xani
author_rank: Frequent Contributor
timestamp: September 21, 2017, 11:52:43 am
content: You can always ask if there is a better way to do something, once you have enough info about what exactly you need to do. Someone might have an idea. Last time I've asked about something here I gotbasicallythe exact chip needed to solve all of my problemsAs for stockpiling components, I just go by "whatever I order, if it's cheap and not 100% project specific, get some spares", over time you will just get some decent library of stuff you can (and know how to) use for your projects.Breakout boards and various modules are also a pretty good idea for experimenting/learning as you can easily re-use them

author: madires
author_rank: Super Contributor
timestamp: September 21, 2017, 01:36:45 pm
content: By a simple internet search. The only problem is to use the right key words. Type in what the component should do and there you go. I'd stock only caps, resistors and a few jelly bean semiconductors. The "it's cheap and maybe I'll need it some day for some project" method is expensive, actually. Take electrolytic caps for example. There are so many different voltages and packages, you can't stock them all. Get components when you need them. Though, I've got half an electronics shop from buying components for my projects incl. a few spares over the last 30 years. Some parts are aren't produced anymore and are becoming rare. Maybe a good investment after all?

author: xani
author_rank: Frequent Contributor
timestamp: September 21, 2017, 09:41:05 pm
content: Quote from: madires on September 21, 2017, 01:36:45 pmWell, I was talking about *the* cheap componets as in below $1 a pop (altho part of my reason why was also "add that few bucks to hit a free shipping at mouser") and "generic enough". I will most likely won't be needing 3 different sizes of 1uF SMD cap or different types of "a red led used for power indicator"