Extreme n00b question dc power jack unswitched

[edson]

Hi,

I was quite sure that  the longer "leg" on those DC power jacks that are unswitched is positive. Well, I was sure that the longer one was positive...

But I've built the huminator from beavisaudio, and a looper pedal from beavisaudio, and they are both not working.. so I wonder if it has something to do with it...

Anyone who can shed some light on this..

Thanks,
Edson

[Govmnt_Lacky]

Picture of the DC jack you are using??

Do you have a DMM multimeter? USe it to verify.

[edson]

Hi,

it is one of these:
http://www.smallbearelec.com/servlet/Detail?no=1362

How do I check it with a DMM? Continuity?

/Edson

[Govmnt_Lacky]

How do I check it with a DMM? Continuity?

Yep! Or ohms. One lead on the center pin and the other to one of the lugs.  That will tell you which is which

[deadastronaut]

long pin is +

i use those all the time.

[edson]

long pin is +

i use those all the time.

Aww.. then I don't know what's wrong with my builds

I guess continuity also confirmed it... center to short pin, beeeep Center negative right?

/Edson

[Govmnt_Lacky]

Aww.. then I don't know what's wrong with my builds

I guess continuity also confirmed it... center to short pin, beeeep Center negative right?

/Edson

Yes. Your center pin should be negative. So your V- or Ground should be all connected to the center pin of the DC jack.

[edson]

Yes. Your center pin should be negative. So your V- or Ground should be all connected to the center pin of the DC jack.

OK. Thank  you. Well, here it is the other short pin, no center pin on these.

I'll guess something else is wrong with these super simple builds then... I have built more difficult things.. but seems like a true bypass looper and a huminator is too hard for me.. hehe.

/Edson

[duck_arse]

govmnt_lacky, you're the designated "read the debugging page"-typer this week aren't you?

[Govmnt_Lacky]

govmnt_lacky, you're the designated "read the debugging page"-typer this week aren't you?

Not yet on this thread!  

Just trying to help someone figure out which DC jack lug is V+ and which is V-

@Edson

I do not think you have a center pin/lug on the BACK of these type DC jacks. The "center pin" I was referring to was on the FRONT.

- Turn on multimeter and set it to OHMS.
- Connect RED lead to the center pin on the front of the DC jack (where you would plug in your power adapter)
- Connect black lead to either of the lugs on the BACK of the DC jack
- Check meter to see if it reads 0.0 to 1.0 (anywhere in between) on the display
- If it does not, move black lead to the other lug.
- If you DO NOT get 0.0 to 1.0 on EITHER of the lugs or BOTH at the same time, then the DC jack is defective.
- Once you find the lug that reads 0.0 to 1.0, that is the lug that connects to the center pin (and should be your V- or GND connection)
- The other lug will be your V+ or 9V connection

Hope that helps  

[deadastronaut]

^ what GL said...

try not to overheat those dc sockets...they melt quite easily.....which may or may not be your problem.

[edson]

govmnt_lacky, you're the designated "read the debugging page"-typer this week aren't you?

Not yet on this thread!  

Just trying to help someone figure out which DC jack lug is V+ and which is V-

@Edson

I do not think you have a center pin/lug on the BACK of these type DC jacks. The "center pin" I was referring to was on the FRONT.

- Turn on multimeter and set it to OHMS.
- Connect RED lead to the center pin on the front of the DC jack (where you would plug in your power adapter)
- Connect black lead to either of the lugs on the BACK of the DC jack
- Check meter to see if it reads 0.0 to 1.0 (anywhere in between) on the display
- If it does not, move black lead to the other lug.
- If you DO NOT get 0.0 to 1.0 on EITHER of the lugs or BOTH at the same time, then the DC jack is defective.
- Once you find the lug that reads 0.0 to 1.0, that is the lug that connects to the center pin (and should be your V- or GND connection)
- The other lug will be your V+ or 9V connection

Hope that helps  

Hmm ok. I get 1 on the long pin, and anything and everything on the short PIN. So it means then that the long PIN is GND and not positive as I first thought.. *confused*

/Edson

[deadastronaut]

the long solder lug is definately positive..

the short lug is negative...the tip!..

ive wired up lots of pedals using exactly the same DC socket...