SMD "grab bag" options? - Page 1
Forum section: electronics / beginners

author: bitman
author_rank: Unknown
timestamp: April 26, 2020, 05:33:24 pm
content: Over time I've found (recovered) a bunch of components from old/discarded stuff, left-over stuff from purchases in bulk etc. I still find myself missing quite a few basic components for a quick SMD prototype. Years ago I would buy grab-bags but they all seem to be retro components only - thru-hole and lots of connectors and stuff I wouldn't not have a need for. Looking for SMD grab-bags and I come up pretty empty.How do you guys source "random" components of capacitors, diodes, inductors and other basic active components? A long time ago I got a sample book with SMD resistors which come in handy; but I find my "stock" of diodes and inductors to be very very small for instance. Or in this case resistor arrays. I've got some thru-hole from these old bags or stuff I've recovered, but otherwise I'm coming up empty. Sizes should be hand-solderable but otherwise I'm not picky.

author: jancumps
author_rank: Unknown
timestamp: April 26, 2020, 05:44:02 pm
content: I've bought cuttape sets of resistors and capacitors from aliexpress.The whole e24 range for resistors. A decent mix of ceramic caps. For a few bucks.I store them in envelopes, still in the tape.A grab bag for SMDs is difficult because often values aren't printed.Prototyping with SMDs has the challenge that you need a PCB.

author: james_s
author_rank: Super Contributor
timestamp: April 26, 2020, 06:00:40 pm
content: IMHO SMD grab bags are of little value. It's too much hassle to sort out the parts and find what you need, and most of the parts are so cheap that it's easier to just buy new stuff of exactly what you want rather than sorting through a pile of random stuff.

author: bitman
author_rank: Unknown
timestamp: April 26, 2020, 06:06:45 pm
content: Quote from: jancumps on April 26, 2020, 05:44:02 pmThe last grab-bag I got about 3 years ago had a handful of strips of SMD resistors. Outside what's printed on the resistor there's no markings on the package. When I purchase SMDs directly from DigiKey or similar, the bag it comes in has the label, but the actual roll or strip with the 5-10 copies of the component does not. Only the unit itself has markings - and we all know you'll find little to no markings on SMD diodes. So I don't know how getting cuttape stuff would be any different. I would expect the components be left-over strips from production and as such I expect to have to figure out the properties of what-ever I get - that's part of the "fun".Needing a PCB is just fine. I'm trying to go from bread-board to "not huge thru-hole" PCB when I make it into something permanent. If I get the right size, I can put them on my perf-board and still hack something together without creating a full PCB.Anyway - with thru-hole I can usually find a drawer with something that gets close to what I want/need - not so much with SMD.Biggest issue for me is AliExpress. I haven't ventured to use them yet. I'm sure it's not a rational thing, but I really cannot get myself to trust it. I've had enough bad experiences with purchases shipped from Hong Kong or mainland China via Ebay to avoid that as a source when I can.Thanks for your input though. I do have the resistors covered, and I got my hand of electrolytic or film based caps (they look electrolytic - like a very small round case - but it just looks way too small to be that). Everything else - that's a problem. And last weekend I could really have used a few SMD resistor arrays. So I'll keep my eyes open for "cuttape" and other offerings.

author: james_s
author_rank: Super Contributor
timestamp: April 26, 2020, 06:08:58 pm
content: Quote from: jancumps on April 26, 2020, 05:44:02 pmI routinely prototype with SMD parts without a PCB. I either deadbug on a blank PCB or solder the parts to those protoboards with a matrix of holes. Many SMD parts will fit between the holes with some care.

author: Old Printer
author_rank: Frequent Contributor
timestamp: April 26, 2020, 07:20:45 pm
content: I work mostly with thru hole components and solder-less bread boards for convenience. I have only been at this hobby seriously for 3-4 years so I started pretty much from scratch. Marlin P. Jones is a surplus type electronics supplier not too far from me here in south Florida that regularly stocks assortments of through hole jellybean components. Maybe another supplier does that on an SMD basis. MPJ does a weekly sale on a rotating basis and in the spring focuses on passives. Over time this gave me the opportunity to build a stock of resistor kits, capacitor kits etc for very reasonable cost. The advantage to this is you know exactly what you are getting, as they are not random, but kits of specific values at surplus type pricing.https://www.mpja.com/Pack-of-255-Diode-and-Rectifier-Service-Kit/productinfo/33412+DI/