Best place to buy bulk components? - Page 1
Forum section: electronics / beginners

author: Acecool
author_rank: Regular Contributor
timestamp: July 02, 2020, 09:04:25 am
content: I want to buy a good amount of capacitors, and other components to have them on hand for repairs.The last time I purchased caps, they were a smaller physical size but the rating was the same so it should've worked, or? But there was a bit of an issue. Still have to work on that.But what is the best place to buy a large variation of caps. ie: 10 to 50 of each value, and which values are the best to stock for common electronics repair - flatscreen monitor power supplies, tvs, etc.. and do you think it is better to buy each component individually from one of the electronic suppliers, or a large kit with a larger variation to have them if you need them??

author: Siwastaja
author_rank: Super Contributor
timestamp: July 02, 2020, 09:59:05 am
content: I like Panasonic FR and FM series for general low-ESR SMPS design and repair, but many others are equally OK.Buy from Digikey, Mouser, or similar proper distributor.Avoid no-brand products.Avoid random replacements. You should understand how the designer originally dimensioned the part. And as it clearly was under-dimensioned (otherwise you wouldn't be repairing it!), you need to understand how to increase the design margin.Clearly using one with a smaller case size is going to wrong direction.Pick one with higher ripple current rating than the original (higher voltage rating is also a good idea). Sometimes this means the capacitance has to increase by a notch as well. This also forces you to a larger case size which is a plus as long as it physically fits.Of course, if the original part is some no-brand cheapest piece of junk, just using a similar-sized Panasonic/Nichicon/etc. is likely to last longer even if you don't increase the specs.

author: OwO
author_rank: Super Contributor
timestamp: July 02, 2020, 10:38:18 am
content: 10 to 50 capacitors isn't anywhere close to bulk buying, it's not even sample quantity. Bulk buying is many reels at a time (4k-10k units per reel).

author: jmelson
author_rank: Super Contributor
timestamp: July 02, 2020, 04:51:10 pm
content: Digi-Key and Mouser have "kits" that have a range of values, maybe 30 - 50 different values in one particular type (leaded, SMT, film, ceramic, electrolytic).Jon

author: wraper
author_rank: Unknown
timestamp: July 02, 2020, 04:59:15 pm
content: Quote from: jmelson on July 02, 2020, 04:51:10 pmAll those kits are a complete rip-off. Unless you have a ton of money and don't care about expenses but have little time to spend, it's much cheaper to buy each value separately.

author: wizard69
author_rank: Super Contributor
timestamp: July 02, 2020, 08:02:01 pm
content: Probably the most important thing to understand here is that you are not buying in bulk. Bulk implies cases of reels or tubes of one component size.Quote from: Acecool on July 02, 2020, 09:04:25 amCaps have improved significant over the years. This has lead to much smaller foot prints and at times can be problem.QuoteYou will save yourself a lot of grief it you buy your parts as need and avoid having stuff sitting on the shelf forever. So for example you have a TV that needs a bunch of filter caps, ordered the sizes you need in large quantities only. This way you KNOW that you have a use for a specific size of cap. Even so I wouldn't go over board on electrolytics. Other caps are a different story as they have good shelf lifes and seeming don't suffer physical storage damage like electrolytics.My personal experience is that large kits of components are a rip off for the repair bench. Get what you need when you need them. Experience will further tell you which ones are hot movers and which might never be used again. For example if you get a range of TV's from the same manufacture it is very likely that they will fail in the same manner, thus needing the same caps.QuoteIn the case of caps stocked for a repair bench I think kits are pretty stupid actually as you pay for stuff you never use and never have enough of the stuff that you do use. You might argue that the case they come in is worth something and that can be true but those cases are usually less than ideal for the storage of electrolytics. Note that I mentioned physical damage to the electrolytics above, that is often due to trying to stuff them in drawers that are too small. This is an entirely different story when it comes to ceramic caps, by pass capacitors and the like. Even if you buy a kit of ceramics you will still end up with a lot of unused capacitors.Now understand I'm talking about a repair bench, a hobby bench or a engineering bench, may have a greater need for a wide array of caps on hand. If you are trying to make money doing repairs you need consider that unused parts just tie up money that could be used elsewhere. There are many ways to look at this but if parts are not turned over in 3 months you probably have a stocking issue.

author: Acecool
author_rank: Regular Contributor
timestamp: August 16, 2020, 10:56:50 pm
content: Not major bulk, agreed... large quantities for a hobbyist or for general repairs.I have purchased thousands of surface mount components in the past so I do have a lot of those - I need through hole components right now. They are typically more expensive too.And they'll not only be used for repairs, but also for designing and making new circuits as I learn the hardware side of design and creation. With software, anything I can envision, I can bring into existence. I want to learn hardware. Having a bunch of these parts can help test various circuits, designs, etc... quickly without permanently mounting - ie: using breadboards.I'm not talking spending thousands on stuff... maybe hundreds. And yes - there will continue to be advances, etc.. and depending on a repair you may need special parts... that's fine. But it would be nice to have general stuff ready to use, along with a good assortment for building sample circuits, etc..

author: Zoli
author_rank: Frequent Contributor
timestamp: August 16, 2020, 11:48:40 pm
content: Quote from: wraper on July 02, 2020, 04:59:15 pmDepends on the kit; let's takethis film capacitor kitas a positive example. It contains 3pcs ofthis 10uF/35V SMD film capacitor. Price(at the time of writing) of the kit - $36.18 CAD ; price(at the time of writing) of the 3 capacitors - $51.03 CAD. I needed 2 of those caps for a project, and for $2.16 CAD I don't mind getting 40 pcs of assorted high quality film capacitors in a nice binder. OTOH, this example can be the exception which confirms the rule.