Banggood resistors

[Stuartambient]

Touch the resistor itself or leads?

The body of the resistor, not the leads.

Ok thanks.  I know there were some posts around that might have mentioned scraping material away to see if carbon or metal.  Sounds like this might be a less destructive method. 

I'll also update the thread in case anyone is interested in results. 

[rstofer]

I bought a resistor and capacitor kit from Jameco Electronics a long time ago.

What I have discovered is that I only need about 8 values of resistors - 220, 330, 470, 1k, 2.2k, 4.7k, 10k, 100k.  I could get buy without the 100k.  The point is, why not just buy a hundred or so of the most commonly used values and then, when you build a special project and plan to order parts, throw in a hundred or so of a couple more values.

There are drawers in the resistor box that I have never opened.  What in the world would I do with megohm valued resistors?

In the ceramic capacitor kit, I use two values:  0.1 uF and 0.01 uF.  Every once in a while I need something in the 22 pF range for an oscillator.   I am more likely to need 10 uF or 100 uF electrolytics or tantalums.

Most of my projects are related to uCs or FPGAs.  But even with op amp circuits, I could get by with my limited selection.  Now, I did use some 1 megohm resistors and 1 uF capacitors for my analog computer but I bought them when I ordered the op amps.  SMD and precision for the resistors and polystyrene for the capacitors.  Nothing I would care to stock.

[linux-works]

lol

.1uf and 1k can get you by for so many things.

there is a special name for them; the 1k is a 'floor resistor' and the .1uF is a 'floor capacitor'.

you know, you need a decoupling cap, its late, you need to finish a project and so you look on the floor for something close.  you end up using a 'floor capacitor'

(grin)

[Stuartambient]

It would be good if I could define which values would be needed and which ones not.  I've been spending more time reading the basic stuff and haven't really had a chance to pick some circuits to try.  However I helped my son get started with soldering, one of the European siren kits.  A great value kit btw for learning soldering and electronics as well. Anyway, it included a 68, 2-470's, 1k, 2-10k's, 2-22k's, 47k, and finally 2-56k.  Seven values and the circuit is somewhere between simple and more complex.  To me, it seems like a big variety of values.  Definitely makes sense though if I have repeating values to stock up on those in particular. 

[janoc]

I can't even imagine why you'd shop for something like resistors at a cheap Chinese retail site like that.

Digikey, of all places, makes a good bit of their money on production quantities of resistors and capacitors.  They're competitive, and manufacturers know it.

Not sure how it is in the US, but here in Europe you pay 7-20EUR shipping & handling for orders under 30-60 EUR (depends on vendor). Also a hobbyist is not going to buy full reels of 4000 resistors of a single value to qualify for the "production quantity" pricing. Here in France I have RS Components the cheapest, with about 7 EUR shipping charge. Digikey is asking for around 15EUR S&H unless I order for at least 60 EUR + customs & BS paperwork, because they ship from the US See why I am buying my resistors from AliExpress?

Most hobbyists want to actually build stuff, not wait months until they have accumulated enough projects to qualify for free shipping from Digikey or Farnell. Paying 10EUR shipping for 2EUR in resistors is nonsense, which is why people buy small quantities from eBay, AliExpress, Tayda, etc. instead. Also the prices are often (much) better. For a penny-pinching hobbyist it makes quite a bit of difference.

I do miss the times when you could you walk up to the counter of your local electronics store and pick up few basic parts, solder, spool of wire and just go home and start working on a project. Having to do everything though mail order is a pain, especially for penny items like that.

[janoc]

I was thinking about them actually.  Seen them mentioned in some other threads.  I'm not sure if I read much on the quality though.  One thing that interested me about them is they have a warehouse in Durango, which is within my state.  Nothing on their site though indicates where parts are located or a way choose.

I can't tell who makes their resistors.  I saw some elytic caps with Vishay on them, so I gather they are for real.

Tayda is quite decent, indeed. Not a large choice, but low prices and they are reliable.

[Stuartambient]

When you get them, check the temperature coefficient. This is a quick and easy test to see if they are in fact metal film or just cheap carbon ones painted blue. To do this, measure the resistance then (while still measuring) touch it with your hot soldering iron. They value should change very little if metal film; max 1 or 2 percent for a couple hundred degree C change. A carbon will change more.

Just wanted to update on BG resistor kit.  I did some random meter reading and overall the 1% tolerance seems to be right.  Also tested with the iron on a 47K.  Started at 46.3, once iron touched it went down to 45.5 (then back up).  Iron was touching the resistor body for 1 - 2 seconds.  So they appear to be metal film, at least according to this test.

[edavid]

If you can wait a bit on delivery, Tayda Electronics might be of interest, as the parts are inexpensive (located in Thailand). Definitely suitable for bread boarding (jellybean parts).

I was thinking about them actually.  Seen them mentioned in some other threads.  I'm not sure if I read much on the quality though.  One thing that interested me about them is they have a warehouse in Durango, which is within my state.  Nothing on their site though indicates where parts are located or a way choose.

For US orders, Tayda does bulk shipments from Thailand to Colorado, then ships the individual orders by USPS from there.

The problem I have had with cheap China resistor kits is that the leads are thinner than normal, so they are a little tricky to use in a breadboard.  They are OK for soldering though.  The resistors I have bought from Tayda have normal leads.

[edavid]

What I have discovered is that I only need about 8 values of resistors - 220, 330, 470, 1k, 2.2k, 4.7k, 10k, 100k.  I could get buy without the 100k.  The point is, why not just buy a hundred or so of the most commonly used values and then, when you build a special project and plan to order parts, throw in a hundred or so of a couple more values.

That may be fine until you start doing repairs, but then it becomes convenient to have a wide range of components at hand.

[Kirr]

It may be worth mentioning that you can often obtain a missing resistor by combining the ones you already have. For instance using network finder tool in my sig.

Most of time it does not make much sense to buy a single resistor - you'd want a 100 for a price break. However it's a waste if the other 99 sit in the box forever. In such case just combine your stocked resistors to get the missing value. Especially useful if you are in a hurry and don't want to wait for delivery.

[Watth]

and if your circuit does not work, is it because of YOU or THEM?

I bought jumper wires (from aliexpress). Oh how fun was it to lose hours trying to figure out why things didn't work (and why mosfets burnt), until I discovered some of the jumper wires were deffective.
Now, if I ever order jumper wire from this type of sellers, I'll have to test each on of them.

[Stuartambient]

I bought jumper wires (from aliexpress). Oh how fun was it to lose hours trying to figure out why things didn't work (and why mosfets burnt), until I discovered some of the jumper wires were deffective.
Now, if I ever order jumper wire from this type of sellers, I'll have to test each on of them.

Makes you wonder how anyone can screw up jumper wires.  Isn't Aliexpress and even Banggood basically multiple vendors selling under one umbrella company?

[linux-works]

I've had jumper wires be bad right out of the bag, before.

I would joke with the sellers:

"look, I bought a bunch of shorts, but you seemed to have mixed in some opens along with the shorts.  they all look the same and I can't tell, so maybe next time, mark the bags with the shorts and don't let the opens get mixed in by mistake"

I'm not sure they ever understood my joke.  and I never buy cheap jumpers anymore.  time wasted makes it false econ.  and I can create my own opens, for free, without any of THEIR help (harumphs!)

[Stuartambient]

I've had jumper wires be bad right out of the bag, before.

I would joke with the sellers:

"look, I bought a bunch of shorts, but you seemed to have mixed in some opens along with the shorts.  they all look the same and I can't tell, so maybe next time, mark the bags with the shorts and don't let the opens get mixed in by mistake"

I'm not sure they ever understood my joke.  and I never buy cheap jumpers anymore.  time wasted makes it false econ.  and I can create my own opens, for free, without any of THEIR help (harumphs!)

Reminds me of a laundromat I once knew.

[Kalvin]

You should make a difference between resistors and precision resistors. Typically the design requires only few precision resistors while the rest of the resistors are used for biasing, pull-up, pull-down, led biasing etc. ie. non-critical non-critical parts of the circuit. Similar situation is with the capacitors, most of the time you require bypass capacitors and less critical capacitors, and require possibly only few precision capacitors. For example, I have bought cheap resistors and capacitors from eBay (assorted kits of TH resistors and capacitors for breadboarding, assorted kits of SMT 1206/0805/0603/0402 resistors and capacitors), knowing that they may used only for the less critical parts of the system. When my design needs precision components, I will order them from a reputable distributor.

[HwAoRrDk]

I bought jumper wires (from aliexpress). Oh how fun was it to lose hours trying to figure out why things didn't work (and why mosfets burnt), until I discovered some of the jumper wires were deffective.

Ugh, that happened to me a while ago. Crappy jumper leads where virtually all of them would not register any continuity on the meter. I thought I'd been ripped off and sent fakes, until I realised what the problem was.

These jumpers had a plastic sheath covering the crimp on the pin (unlike most others I've seen where it is moulded rubber) that was glued on. The problem was that the glue was also all over the pin too! It was some kind of cyanoacrylate (superglue) that is virtually transparent, so I hadn't noticed it.

Scraping the glue off the pins with a knife soon restored them to proper working order. But it was a tedious pain to go through all 100 in the pack.

What a dumb way to assemble jumper wires - rendering them useless out of the box. I'm going to steer clear of those in future and always buy the moulded kind.