Author Topic: Weird Maplin resistors in value pack...  (Read 1692 times)

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pott

Weird Maplin resistors in value pack...
« on: May 27, 2008, 10:34:46 AM »
I wasn't expecting anything amazing but I'm a little baffled. Value measured:

115R
90R
11.2R
1.06K
3.3K
53K
7.9K
360K
1.3M
23.8K (very tiny tiny resistors)


So er... what?

Don't buy Maplin's bundle packs  :icon_redface:

I'm thinking about doing a giant order of mouser or small bear.

GREEN FUZ

Re: Weird Maplin resistors in value pack...
« Reply #1 on: May 27, 2008, 11:08:18 AM »
I don`t get it, what are you saying? They`re all unusable?

spud

Re: Weird Maplin resistors in value pack...
« Reply #2 on: May 27, 2008, 11:13:56 AM »
You can try Futurlec - or Electronix Express - both sell those "Value" packs, although I think elexp calls them "kits or surplus".

Futurlec:

http://www.futurlec.com/ValuePacks.shtml

Electronix Express

http://elexp.com/srp_qtr1.htm

Not sure what Mouser or Small Bear sells like this.  

One word of caution:  Futurlec can take a while - I had an order take 1 month.  If you don't need it right away, they have good prices and shipping (at least to the US) is relatively cheap.   They are in Malaysia (Singapore), I believe.  

spud

pott

Re: Weird Maplin resistors in value pack...
« Reply #3 on: May 27, 2008, 11:15:10 AM »
I don`t get it, what are you saying? They`re all unusable?

Nah, they measure on the multimeter so they're fine. It's just values I hadn't ever heard of before :P I'm wondering how I can use them. Some don't even fall close to values I've used.

spud

Re: Weird Maplin resistors in value pack...
« Reply #4 on: May 27, 2008, 11:36:18 AM »
Actually, I don't see any issues with what you got.

From the electronix express resistor kit:

"1/2 Watt
5 PIECES EACH OF THE FOLLOWING:
10, 15, 47, 56, 68, 91, 100, 120, 150, 180, 220, 270, 330, 390, 470, 560, 680, 820, 1K, 1.2K, 1.5K, 1.8K, 2.2K, 2.7K, 3.3K, 3.9K, 4.7K, 5.6K, 6.8K, 8.2K, 10K, 12K, 15K, 18K, 22K, 27K, 33K, 39K, 47K, 56K, 68K, 100K, 150K, 180K, 220K, 270K, 330K, 390K, 470K, 680K, 1M, 1.2M, 2.2M, 3.3M, 4.7M, 10M" 

So, based on your list:

115R   = +-5% of 120
90R     = +-5% of 91
11.2R   = +-5% of 10
1.06K    = +-5% of 1k
3.3K      = +-5% of 3.3k
53K       = +-5% of 56K
7.9K      = +-5% of 8.2k
360K     <> +-5% of 390k or 330k (~7-8% off) (what is color code? What is tolerance - Gold/Silver)
1.3M     <> +-5% of 1.2k or 1.5k  (~7-8% off) (what is color code? What is tolerance - Gold/Silver)
23.8K    <> +-5% of 22k or 27k  (~7-11% off) (what is color code? What is tolerance - Gold/Silver)

The first set is within tolerance for 5% (gold) and easily for 10% but the last 3 depend on the color code and the tolerance. 
Acutally, all depend on color code and tolerance - I assumed they were intended as "standard"  values.  So, a key question is:  What is the forth band: Gold or silver? - If they are silver they are 10% and all are ok.  So no problems.   I assumed they were gold since that's the most common.

But with value packs you may be getting silver... 

spud

GREEN FUZ

Re: Weird Maplin resistors in value pack...
« Reply #5 on: May 27, 2008, 11:40:16 AM »
I guess the way I would look at it is, some of the values are close enough to do the job, if the circuit isn`t too critical, i.e 1.3M is close enough to 1M. Would be usable in an SHO for example. 1.06k is " close enough" to a 1k. I`ve just built a Tremulus Lune. There are 4 1k`s in there if I remember correctly.
I couldn`t believe how much the values recorded by my DMM on a set of 5% tolerance resistors varied from what they were supposed to be and yet they seemed to work.

I guess with those "value packs" the real value is completely subjective and only evident if you can find a use for them. Otherwise it`s just a way for the manufacturer to get rid of their excess crap.

pott

Re: Weird Maplin resistors in value pack...
« Reply #6 on: May 27, 2008, 12:57:30 PM »
What surprised me is that all the resistors within one frame are the same exact value...


I can't read color codes. My eyes aren't good enough even with full correction. I really can't make up the different dark or light colors.

Paul Perry (Frostwave)

Re: Weird Maplin resistors in value pack...
« Reply #7 on: May 27, 2008, 11:22:17 PM »
They aren't really weird, if you compare them with the E24 list of standard resistor values: http://www.logwell.com/tech/components/resistor_values.html
Except for the 7.9K!  that looks a bit off..

col

Re: Weird Maplin resistors in value pack...
« Reply #8 on: May 27, 2008, 11:39:15 PM »
If you are in the UK order resistors from rapid. You get 100 1/4 watt carbon film for 50p plus vat and postage. The packets they come in are all clearly marked and even if you only order the likes of 100R, 1K, 10K, 100k and 1M it won't break the bank. Last time I ordered from rapid though they had started charging p&p over 25 when it used to be free.
I bought one of those resistor packs from Maplins a few years ago and there were some odd value carbon comps in there along with some green ones which said 500ohms on them. Thre were also some 2 pin red wire wound resistors with the colour code marked in paint dabs. I have been able to use some of the resistors from the pack but others were out of tolerance wrt the colour code on them. I'd be worried about the values drifting over time as well, I don't think they are top quality items.
The diode pack was better value I thought, I managed to use most of them up apart from the SM ones that were included.
Col

demonstar

Re: Weird Maplin resistors in value pack...
« Reply #9 on: May 28, 2008, 12:26:22 AM »
I've had one of them resistor packs from Maplin before and I've found it very useful for filling in those values that you only use once or twice in between the need loads of use all the time resistors. Some of the values I got in the pack have been dead useful for breadboarding when an approximate value will do.

Many of the resistors have also ended up in builds. The diode pack was pretty useful too all round. I must get myself a cap pack to try and I'm going to try the futurlec packs one of these days.
"If A is success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut"  Words of Albert Einstein

selectortone

Re: Weird Maplin resistors in value pack...
« Reply #10 on: May 28, 2008, 12:35:17 AM »
I bought one of those Maplin packs with the weird values. I've found them useful for making up a resistor value for one I'm missing. Cheap enough to series or parallel up to get something working until my next order.