Beginner's gripe: 120 ohm vs. 10k resistor

[thedanielwilliams]

9V batt, LED, mystery resistor.

A 120 will be very bright.

A 10K will be very dim.

Thanks, PRR. This'll definitely help!

[darron]

when testing resistors with a DMM, if it comes up with the right number, does that also indicate that the resistor is not fried?   If it was fried, would it just say zero? 

probably the other way around. Metal film resistors should be fusing, so rather than reading zero, a shorted closed circuit it would break the circuit and have a practically infinite reading. Good question though as I'm curios to know if a resistor can be partially damaged and still read correct.

I've had the same problem of looking at resistors upside down in a circuit where they look identical. There's little dfference.

I was working for an amp manufacturer and know that you do have to be weary of relabelled stuff. I saw something with cheap HT electros that were like 22uf wrapped in another casing, wrapped in another another casing, then labelled as 47uf. It was like a Russian doll! No chance the vents would ever work if they blew. Certain companies/countries do dodgy things... Your supplier might not pickup on faults too, so it's up to you.

[walker]

so then how do you tell if a resister is toast?  Or for that matter a Cap, diode, or other component.  My DMM has a spot for the transistors.  I'm asking because I recently caused a little fire in a volume pot, I think by hooking up v+ wrong, and I wonder what other parts in lit up.   Also, none of my circuits ever work. 

[Taylor]

Resistors and diodes rarely get fried in 9v pedals. Electro caps pop loudly, smoke, and the metal vent splits or domes if it's fried. I've never managed to fry a non-polarized cap, so I don't know what would happen, but I doubt you've done it. When things blow because of wrong power hookups, it's usually electro caps, ICs, and the occasional pot, as you've seen.

[philbinator1]

so then how do you tell if a resister is toast?  Or for that matter a Cap, diode, or other component.  My DMM has a spot for the transistors.  I'm asking because I recently caused a little fire in a volume pot, I think by hooking up v+ wrong, and I wonder what other parts in lit up.   Also, none of my circuits ever work. 

Dude..i feel your pain       do you breadboard stuff?  that's what i've started doing, after too many disapointing failures...going back to basics too, i tried to run before walking. 

[walker]

Thanks Taylor, that's good to know.   Philbinator... I just started.  I build myself a "beavisboard", and have tried several circuits, non have worked right yet.   

[philbinator1]

Thanks Taylor, that's good to know.   Philbinator... I just started.  I build myself a "beavisboard", and have tried several circuits, non have worked right yet.  

I got 2 books by brian wampler, "how to build fx" and "how to mod fx"...they have great starting projects in them.  and if you join up to his mailing list
you get huge discounts, i think i got mine for US$15 each when they are usually $39, i believe.  one of the projects is a "one component at a time" type
of deal, where you breadboard it and can hear the diff with each new component.  very cool!

Edit, i should add they are e-books.

[deadastronaut]

wouldnt it be easier if they just wrote 10k etc on the things!.............

nothing is simple i guess!............

[Taylor]

wouldnt it be easier if they just wrote 10k etc on the things!.............

nothing is simple i guess!............

There are actually resistors with a value code written on them:



But it's not the value, but a code of significant bits followed by a multiplier. Still a little confusing, but easier to read than bands to me.

The reason the band system is done more commonly is that they can be read no matter how they were inserted. The bands are visible all the way around the part, as opposed to those coded ones which can only be read if inserted with the part number up. In cheap 'n' fast manufacturing, having to orient the resistor up wastes expensive microseconds.

[deadastronaut]

they look like little hot dogs...lol..

[served]

And this led me to an idea, that I must build to myself. A experiment board which is very easyli conntected with multimeter, by somekind of sockets that suits with multimeter fires or something. So when I am building something and I doubt, I just plug a component in the board and ready. Could not think of a faster way to do it.

[trendyironicname]

And this led me to an idea, that I must build to myself. A experiment board which is very easyli conntected with multimeter, by somekind of sockets that suits with multimeter fires or something. So when I am building something and I doubt, I just plug a component in the board and ready. Could not think of a faster way to do it.

I wound up hacking an old pair of leads and 20ish solid core wire so that while i'm breadboarding I can throw those in instead of the probes and plug them into dif places on the board and they'll stay. I have alligator clips permanently soldered to a pair also.

[MoltenVoltage]

ZIF sockets are excellent for testing chips and other components.  The ones with the little lever work best.

This is just one example:
http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/224-1286-00-0602J/?qs=sGAEpiMZZMv9Q1JI0Mo%2ftTqfDQB3DcEg

[Paul Marossy]

I'm glad that I'm not the only one that can't figure out these five band resistor codes. 

[Skruffyhound]

 I have to admit that I only bother with the codes if I'm looking for something in my junk pile. Otherwise all my values are marked on their containers and I'm as anal/OCD as Greg because I check every resistor as I build something. Never had the "same code different value" problem, why I didn't catch the point of the OP.