Yellow and White

[Wombat]

OK,i got these LED's and they are pre wired using one white wire and one yellow wire.Which one is the positive using this sort of combo?
I've sent this question to the seller but so far i have had no reply and i don't wanna seal up the shuttle till i know which is the correct way to have it wired up for good.

All help,as always,is very appreciated!!

[erospawn]

(01-27-2010, 11:13 PM)Wombat Wrote: OK,i got these LED's and they are pre wired using one white wire and one yellow wire.Which one is the positive using this sort of combo?
I've sent this question to the seller but so far i have had no reply and i don't wanna seal up the shuttle till i know which is the correct way to have it wired up for good.

All help,as always,is very appreciated!!

Do you have a picture? The positive (Anode) is the longer lead. The cathode should be the shorter lead....But, since they've been pre-wired, the leads could have been trimmed. Did any documentation come with the package? The standard is usually the black wire is the negative, and white, red or yellow is the positive..

[Wombat]

(01-28-2010, 12:09 AM)erospawn Wrote: Do you have a picture? The positive (Anode) is the longer lead. The cathode should be the shorter lead....But, since they've been pre-wired, the leads could have been trimmed. Did any documentation come with the package? The standard is usually the black wire is the negative, and white, red or yellow is the positive..

Hey Ron,nothing can be that easy mate.No documentation and i still haven't heard back from the seller.I was hoping to be able to tell from the length of the anodes but they have been cut back it seems.I had a couple of spares so i just removed the heat shrink covering and there is a resistor on one anode and someting else on the other anode.
Just looking at them more there is a flat edge at the base of the LED on the white wire side.So instead of it being round on the base section it has a D shape to it,if that makes sense.
Heres a picture of it unwrapped.

[erospawn]

Its Anode and Cathode.. The resistor should be on the Anode.. But, the other thing is a Diode, a one way gate... so what they've done here is made it so you can't hurt it if you connect it backwards. The diode acts as a one way gate, so if you hook the led up backwards, the current won't flow and you won't fry the led.

[Wombat]

Mate,thank you!!

Anode/Cathode,you can see i still don't know a real lot about any of this.
Anyway,it looks like i've had them wired up correctly as they worked.The only thing was i was taking it that the white wire was the negative and wired em up this way.But it looks like the resistor is on the white wire side so i'd have thought that was the positive side?Either that or i'm not reading my transformer correctly and what i thought was the positive was the negative pin.
Anyway,if they have the safe gaurd with the diode i guess even a wombat like myself can't really mess up too much??
I just tried wiring one up opposite and it doesn't light,the diode must be doing it's job.

Cheers again mate for your help Ron!!

[JAWS]

And we all learn from these questions & answers. Thanks Ron!

[DarthDuck]

(01-28-2010, 06:06 AM)erospawn Wrote: Its Anode and Cathode.. The resistor should be on the Anode.. But, the other thing is a Diode, a one way gate... so what they've done here is made it so you can't hurt it if you connect it backwards. The diode acts as a one way gate, so if you hook the led up backwards, the current won't flow and you won't fry the led.

I don't know why they bothered?

An LED is a diode (Light Emmitting Diode) in and of itself and usually (I've never heard of it) will not fry if hooked up backwards. It's only too much current that will fry one.

For future reference Phil: That flat edge side is the negative.

[erospawn]

well yes an LED is a diode... And I have heard of popping an LED wired up backwards.. at anyrate the diode has a higher current rating and is a "super safety feature"..perhaps overkill.

[DarthDuck]

(01-29-2010, 01:30 AM)erospawn Wrote: well yes an LED is a diode... And I have heard of popping an LED wired up backwards.. at anyrate the diode has a higher current rating and is a "super safety feature"..perhaps overkill.

There's going to be a lot more load that way and drain the battery or overheat it- possibly, just possibly.

[erospawn]

the resistor detemines the current.. The only thing you would need to compensate for...if you really wanted to was the additional forward voltage across that other diode.. .7 volts..either way all the manufacturer did was guarantee things would be ok..

[DarthDuck]

(01-29-2010, 01:42 AM)erospawn Wrote: the resistor detemines the current.. The only thing you would need to compensate for...if you really wanted to was the additional forward voltage across that other diode.. .7 volts..either way all the manufacturer did was guarantee things would be ok..

Overkill.

[Wombat]

(01-29-2010, 01:23 AM)DarthDuck Wrote: For future reference Phil: That flat edge side is the negative.

Thanks DD!!
So that it looks like they have the resistor on the negative side (white wire/flat edge) for some reason with these particular LED's?I thought the resistor would have been on the positive side but all that matters is they work,and they seem to do that just fine.

[erospawn]

It doesn't really matter on which side the resistor is on, the current is still going to flow from negative to positive. Most people like to keep things simple by putting the resistor on the positive side like you might see in a schematic. +5 volts ----/\/\/\/\/\----|>---------- OR +5volts ------|>-----/\/\/\/\/\------- its the same thing. PS, the squiggly line is the symbol for a Resistor NOT an LED. The triangle is the LED with the arrow facing in the direction of current flow..

[DarthDuck]

(01-29-2010, 07:39 AM)erospawn Wrote: It doesn't really matter on which side the resistor is on, the current is still going to flow from negative to positive. Most people like to keep things simple by putting the resistor on the positive side like you might see in a schematic. +5 volts ----/\/\/\/\/\----|>---------- OR +5volts ------|>-----/\/\/\/\/\------- its the same thing. PS, the squiggly line is the symbol for an LED. The triangle is the LED with the arrow facing in the direction of current flow..

Minor typo- the /\/\/\/\/ is a resistor.
I know you know that.

[JAWS]

I didn't so thanks for the correction. So its like this.
Dotted line is current?
Squiggley line is a Resistor?
Line with point is LED & point represents direction of current flow?

[erospawn]

Well, the dotted line was acutally supposed to represention of a solid wire. It was believed that current flowed from positive to negative way back when.. but now we know it acutally flows in the reverse.

[JAWS]

Om man keep it simple for us Aussies! We were on a roll brother.

[DarthDuck]

(01-29-2010, 10:09 AM)erospawn Wrote: Well, the dotted line was acutally supposed to represention of a solid wire. It was believed that current flowed from positive to negative way back when.. but now we know it acutally flows in the reverse.

Except for those in the southern hemisphere where it is akin to the draining of a sink. It spins opposite and therefore current also flows reversed.

[JAWS]

You don't miss a beat do you duck!

[DarthDuck]

(01-29-2010, 05:59 PM)jasonwright.1972 Wrote: You don't miss a beat do you duck!

I'm here all week folks! Try the veal and remember to tip your waitress.

[erospawn]

Hey Phil, Cobra suggests this site: http://led.linear1.org/led.wiz
It is a very helpful site that will help you understand.