Newbie question about resistors

Hi guys, I bought an Uno to learn about electronics and I played it safe by buying a starter kit. It now seems like it was a pretty pathetic starter kit as resistors seem really important and it didn't contain any (I really know nothing about electrics). I'm going to buy an assortment kit and I got it down to 0.25 watt E6 resistors but I'm not sure about tolerances. I'm looking at one of these two: http://cpc.farnell.com/_/cfr0w4je006kil/resistor-kit-0-25w-5-e6/dp/RE03404

or

http://cpc.farnell.com/_/mf0w4ffe006kil/resistor-kit-0-25w-1-e6/dp/RE03418

I'm guessing higher tolerances are better for me but could someone please set me straight before I waste £20. And while I'm at it is there anything else I could do with (I'm guessing I should t be bothering with capacitors or anything yet). Also I work as an IT Technician and I get my hands on lots of broken old bits, is there anything that's particularly juicy that I should look out for?

Any help is appreciated, thanks.

You won't use anywhere near that quantity or range of resistors to get you started with your Uno.

A dozen or so 270Rs and maybe some 1.2Ks and 10Ks will do fine - and a couple or three of 74HC595 shift register ICs.

You'll also need some LED's.

Did your starter kit include breadboard and wires 'cos you'll need those too.

Ebay is great for assorted resistors, for 20£ u vould gets probably thousands(total), and you could split it up all ways, 220(led 5v), 480 (led 12v), 1k(useful for alot), 10k(a good pullup/down size), 22k,33k,220k,330k,1M,2.2M, some potentiometers(1k/10k/100k), dozens of leds(5mm,1w) , some lm317(good for constant current, adj voltage supply), 555 timer(dozens if not hundred of uses, I got 20 for 10cents a piece!), some diodes, (zeners, shoctky, regular), plenty of general purpose transistors(pnp, npn), maybe some mosfets all that probably less than that bundle

Thanks for the answers. I just looked at those links I posted and realised they were a bit misleading as you don't just get 100 resistors, you get 100 of 22 different types of resistors. I was planning on making 2200 LEDs blink at once but I guess I can give that a miss. I did actually look on eBay but none of the assorted packs of resistors seemed like what I was after but that was a few weeks ago so I guess I'll have another look and see if it's changed, maybe raise my budget a touch as I think when I was looking I didn't want to spend much more than £5.

The kit I bought came with a few LEDs, a breadboard, some cables and a USB cable. I did actually head into town after realising I needed a resistor for the second tutorial and I bought 10 220s and a 330 but I wanted an assortment so I wasn't wandering into town for each one I needed spending 2p a time. I'm snagging an old CD drive from work that I'm hoping to get a motor out of as well so I hope I'll be sorted to work my way through a few tutorials.

Thanks.

Hi, at the risk of mentioning my own shop, I went looking for good assortments of resistors and found some at a good price in China.

If 20 resistors of each of 20 values is enough, see http://goo.gl/bKhfv

DISCLAIMER: Mentioned stuff from my own shop...

Twinnie: I'm guessing higher tolerances are better for me but could someone please set me straight before I waste £20.

Very few projects require high tolerance resistors. It doesn't hurt to get them, but it doesn't really matter if you don't.

high tolerance resistors

In my understanding tolerance just tells how precicely you can rely on the nominal value.
If at all, a low tolerance (5% or 1%) were required (or do you call 1% higher than 5% ? English is not my native tongue …)

My experience says, any cheap resistor is fine for simple experiments, and the nowadays usually available tolerance (5%) is not required:
Even a set with doubling values only ( 1, 2.2, 4.7, 10, … ) should be usable in most cases, which means you could even live with 30% tolerance.

If it’s about 2200 leds however, you should know what you really need (depending how many are running in a series with a common resistor on which power supply, that resistor should be calculated properly in resistance and power dissipation.

or do you call 1% higher than 5%

Yes the smaller the percentage the higher is the tolerance.

Yes the smaller the percentage the higher is the tolerance.

I would say that this is backwards, but that may be a result of a difference between American English and British English.

Let me try to rephrase some of these answers and give an example.

The devices with a lower percentage number are more likely to have a resistance close to the marked value. Here are some examples for a resistor with a nominal value of 1000 ohms:

10%:  1000 +/- 100 --> 900 to 1100
 5%:  1000 +/-  50 --> 950 to 1050
 1%:  1000 +/-  10 --> 990 to 1010

Don

Here is a related side note that may be of interest.

Back in the stone age, when electronic devices had filaments and would burn your fingers if touched when operating, 20% resistors were not uncommon but most resistors in use had 10% tolerance.

We ran an experiment in our circuits lab where we measured hundreds of 10% resistors and we found that NONE of the 10% resistors were within 5% of the nominal value. They were all either 5-10% low or 5-10% high.

It seems that the resistor manufacturers would make a batch of resistors and then measure each one. Those that were within 5% of the nominal value got a gold band. Of the remainder the ones within 10% got a silver band, and of the remainder from that batch those that were within 20% got no fourth band. The leftovers were put in a plastic bag and sold by Lafayette Radio.

A similar experiment done much more recently did not give similar results. If I remember correctly the 10% resistors were spread out among the entire range.

Incidentally, we did our measurements using a Wheatstone bridge since Volt-Ohm-Milliammeters (VOMs) and Vacuum Tube VoltMeters (VTVMs) were notoriously inaccurate for measuring resistance.

Don

Very few projects require high tolerance resistors. It doesn't hurt to get them, but it doesn't really matter if you don't.

I found it hard to understand Texas English when I was there so maybe it's me, but I would say that this is backwards as well. My version of this statement would be: "I would say that very few projects require high precision resistors...."

The way I look at it a high precision resistor is one with low tolerance.

Don