do you guys use DMM?

Started by 9V, June 30, 2004, 12:27:20 AM

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9V

digital multi meter... is that essential for knowing if the pedal is wired or soldered wrong? what does a digital multi meter do? does it come saying if i had certain parts wrong?

because, i have on my desk, tons of failed project, and whenever i try and look, and do the thumb test(?), i can't seem to find the error, therefore making the stompbox frustrating..

please help this beginner out, thanks
i haven't given up just yet!

niftydog

it's not essential really, but boy does it make a huge difference!

It can find dodgy solder joints, faulty wiring, damaged components, incorrect voltages, cracked PCB tracks etc etc etc.

A good one will read an impressive range of capacitors, check diodes, give you frequency readings, measure the beta of a transistor, measure ripple on DC, measure duty cycle, temperature etc etc.

BUT, you gotta know how and when to use it, and what to expect when you do use it, otherwise it's pointless.

say you're check bias conditions on a transistor, you have to have a vague idea of the voltages you should expect at each pin, otherwise, you don't know if it's right or wrong!

Oh, another thing, don't skimp on a DMM. A well looked after, good quality DMM will last you forever and day and it will give you better results than a cheap nasty one.
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

zener

Yes of course. It is an indispensable tool in any electonic hobby and career you may want to pursue, including of course, stompboxes.

You use a dmm to check and measure voltages, dc or ac (the one that kills) and check and measure resistances or the lack of it (shorts or continuity).
There are a lot more uses of a dmm but what were mentioned are just the two most common use of it for this hobby of stompboxes.

Most of the time, a dmm and an audio probe are all you need to debug those not-working stuff you made.

BTW, how many are those? Do they have many parts? Have you improved your soldering already? I can still remember your Electra distortion where your solder joints are big blobs of solder :wink:  

Go get a dmm and debug, debug and debug :)  Good luck
Oh yeah!

Peter Snowberg

I have two digital meters and one analog. I'm almost useless without at least one.

Even a very inexpensive meter will help an amazing amount! :D

Take care,
-Peter
Eschew paradigm obfuscation

rogerinIowa

hey 9V-

I am "Nearly Newbie", but I use a DMM...I cannot imagine working without one, as I am truly red/green color blind and cannot read the markings on parts ( esp. resistor codes) accurately.

Tip: measuring parts before you install them will save you alot of time and headache in the future. example- I use my DMM (set to measure resistance) and check the value of each resistor before i solder it onto my PCB. The other day I caught a mistake on a wah board, I had pulled out a 330K resistorfrom my bin, when i needed 330 ohm resistor...big difference.)

I would say "Good luck" but a DMM reduces some of the NEED for good luck!

regards,

rogeriniowa
friends dont let friends use stock pedals.

travissk

Yes, especially if you're in the US, there are some models which are really cheap. Even if you're on a budget, a analog meter or not-quite-perfect digital meter that will help you get in the ballpark on measurements, test for continuity, etc.

If you have the money, go for a better one. I'm admittedly using a Radio Shack digital meter, since I didn't get a free meter from circuit specialists last time I ordered, and never followed through on that.

Speaking of which, if you ever order $50+ worth of parts, see if you can do it from CircuitSpecialists.com and they'll send you a free meter with their coupon code. It's a midrange-level meter from what I can tell, and should serve you well for a free meter.

Whatever the case though, if you think this will be a fairly serious hobby, it definitely makes sense to have one, especially when Hammond enclosures cost more than a meter :)

smashinator

I have Circuit Specialists' "True RMS" DMM, and it has everything I need right now (the usual stuff, plus it tests caps and measures hfe), and some stuff I assume I'll be able to use in the future (I'm pretty new to electronics).  I think it was about $60, and I'm happy with it now that I've figured out, mostly, how the heck to use it.

Circuit Specialists used to be right down the street from me (now they're WAY down the street from me), and I've been pleased with everything I've gotten there.  Right now I'm saving my pennies to get a good soldering iron.
People who say it cannot be done should not interrupt those who are doing it. - George Bernard Shaw

http://pizzacrusade.blogspot.com/

Paul Marossy

Buying a DMM was one of the best investments that I ever made!

sir_modulus

Same here. Use it for everything (can't read the resistor bands, or is it metal film with a brown covering, NP. need to find shorts? NP) It's utterly indispensible. Second to the soldering iron in importance.

Paul Marossy

"Second to the soldering iron in importance."

Well, after all, without a soldering iron, we wouldn't have a circuit that would stay together!  :wink:

Peter Snowberg

Quote from: Paul Marossy"Second to the soldering iron in importance."

Well, after all, without a soldering iron, we wouldn't have a circuit that would stay together!  :wink:
Ever have the "privilege" of dealing with wire-wrap? :D

Take care,
-Peter
Eschew paradigm obfuscation

Hal

there are some cheep ones on e-bay that do the trick...if you dont wanna spend money to get a nice one yet.  

they're yellow...and test Hfe :-D

Peter Snowberg

The big problem with really cheap meters is that they don't do well reading large resistors, but other than that, they're essential.

If you can get one that reads hFE, so much the better. I have a Radio Shack meter that not only reads hFE, but it tells you if the transistor is NPN or PNP and it tells which pin in which too. It's too bad they don't carry it any more, but it's a great feature to look for.

Having a capacitor reading function is also a wonderful thing, but resistors, continuity, voltage, milliamps, and diode forward voltage will be the most used settings for most people, most of the time.

For the continuity testing you can use a resistance scale, but many meters have a mode that makes an audio beep when continuity is detected. That way you don't have to watch two things at once.

As Paul said....
QuoteBuying a DMM was one of the best investments that I ever made!
It pays to spend a little more to get a good meter in the beginning. It's just like a measuring tape is to a carpenter.

Take care,
-Peter
Eschew paradigm obfuscation

puretube

Quote from: Peter SnowbergI have two digital meters and one analog. I'm almost useless without at least one. :D

Take care,
-Peter

I gotta admit, that my scope has taken over most of the tasks of the latter one.

As long as the Ri is high enough, you can get along with analog.
(Do you remember the times, when all "pro" measurements where taken with a "Tube-Volt-Meter" > 1Mohm...?).

OT: BTW, what was the english name of that lineal-type thing we used to use before the arrival of the electronic calculator? - slide rule? -
:)

aron

I think it's essential and given that they are fairly cheap now <$20 I would consider it a must have.

Hal

Quote from: puretube

OT: BTW, what was the english name of that lineal-type thing we used to use before the arrival of the electronic calculator? - slide rule? -
:)

an abacus ?

puretube

no, that`s counting marbles on a row, like they still did in russian shops
(-no, you couldn`t call that: "supermarket" -), a few years ago.

(i shoulda wrote: "ruler" insteada "lineal" in last post...)

Arno van der Heijden


maximee

there you go :)

slide gage [tech.]        die Schiebelehre  
slide gauge [tech.]      die Schiebelehre  
sliding caliper [tech.]   die Schiebelehre  
sliding calliper [tech.]  die Schiebelehre  
sliding rule [tech.]       die Schiebelehre

( www.leo.org )

petemoore

New Clipper just built.
 Used the meter about 5 times.
 On a build that doesn't fire up right away, I'd use it exponentially more times, and it allows me to find problems much much more easily, or at all.
Convention creates following, following creates convention.