resistor/capacitor packs

Started by scaesic, August 24, 2005, 10:22:05 AM

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scaesic

does anyone knwo where you can buy a big pack of different valued resistors?
id like something quite like this i found :

http://www.fastcomponents.co.uk/index.php?cPath=39&osCsid=0583cbd67486e77ceb50dcb77f578d55

but id quite like to have 300k resistors, and not 270k's etc.

scaesic

p.s what would it make a drastic difference to the circuit if all the components were consistently out by the standard amount. i.e 270k in place of 300k, 27k in place of 30k etc etc.

petemoore

I bought a 500 pack from RS yesterday.
 Kindof expensive but it does have 4m7's 2m2's etc big resistors and all the leads are nice and long.
 I haven't seen a 300k 'resistor' but you could put a 27k or 33k series to a 270k, to get 300k.
Convention creates following, following creates convention.

scaesic

yeh i know you can do that, its just the schem uses 300k's etc and the layout on the pcb print out i have only has space for one resistor. and it does that consistently through out the circuit. i know swapping one for a 270k wouldnt make much difference but changing the whole circuit....

petemoore

Shape the resistor built from two resistors so that when mounted they're looking like an upside down V.
 27 into 30 = close to 10%, over a few stages it might matter, pretty much depends on stuff too though.
 I'd try hunting down some 300k's or just stick something in there you think'll work.
Convention creates following, following creates convention.

Paul Perry (Frostwave)

Whether you can sub 270K for 300K, unfortunately depends entirely on the circuit. I will say this, though... there aren't many simple FX circuits where a +- 10% change makes a noticeable difference.
And if you are worried that there is only space for one resistor, but you have to make a substitute, make a parallel sub instead of a series one. OK, the maths is harder :x but, just connecting the resistors in parallel takes pretty well the same space (though it's a bitch soldering the second one).

scaesic

cheers, i dont think there are any combinations for 300k in parallel, 2 620k's would give 310k though, which is a lot closer than 270 or 330., unless theres another way of doing it, but its a good point, easier than putting them in series over the space for one resistor.
i might try and hunt some 300ks though, they must be somewhere, just not in the standard packs.

Paul Perry (Frostwave)

300K is a standard 1% value.
Or if you want common resistors, then 330K in parallel with 3.3M is remarkably close.
A nice parallel finder here:
http://www.radio-electronics.com/info/circuits/resistors_in_parallel/resistors_in_parallel.php

Joe Hart

Cool site, Mr. Perry! That's one to bookmark! Thanks!!
-Joe Hart