Cheap source for 0603 PRE WIRED Warm White LED's

[Lemosteam]

Thanks peteski, you have a great ability to bring the discussion down to laymen's level for an electronics dolt like me.  I like your tester, but would pot work as Dave Schneider suggests?

[victor miranda]

ummmm.

peteski?
did you hack open a 9 volt battery just
to get the two connector buttons off the top?
really?

.... once I recall you saying you were cheap...
 
I am beginning to see the truth in the claim.

And by the way,
that is a darned good idea...

I used 6 volts and a 600 ohm resistor for my LED tester.

victor

[DKS]

I used 6 volts and a 600 ohm resistor for my LED tester.

Mine, 4.5 volts (3 AAAs in an old battery holder) and a 470 ohm resistor.

[victor miranda]

hohohohohoho!

pictures or it don't exist!!!

LED tester showdown!  Bring it!

why am I laughing?

I'll get a photo of mine up some time tonight

( I expect to lose but I want the ideas )

[DKS]

The battery holder is from an old Miller Engineering EL sign; resistor is inside the shrink-wrap in the middle of the black wire.

I've planned for a long time to build an "LED Evaluation" unit: a box with two rotary switches, one that taps various voltages, and one that selects one of a number of resistors. Mostly it would be used to decide what power supply would be best to illuminate various white LEDs such that they're bright without looking like supernovae. One of many moldy old round tuits. I have all the parts...

[Lemosteam]

Ian, here are the pics of a powered LED.  I took both with a black background and various exposures so they would not wash out.  I hope they help you. 

I think these are used for lighting artificial door wreaths or table centerpieces.



Here is a pic of the package (36 light unit):

[victor miranda]

I made mine to test surface mounts.  and I forgot that I populated the battery box with NiMh cells
so it runs at 5 volts.  here it is lighting a 0604.

[Ian MacMillan]

Ian, here are the pics of a powered LED.  I took both with a black background and various exposures so they would not wash out.  I hope they help you. 

Thanks so much. Those look much more warm white to me.  The other half wants to head out shopping today...so looks like a trip to WalMart is in order.

[peteski]

Victor,
you want pictures? Ok here you go.

I built this thing probably close to 30 years ago.  I wanted simplicity.  I used a top of a dead battery because I needed a sturdy platform for the components of the tester.  I also wanted it to be a simple one-piece unit. Since the tester sits on top of the battery, I accomplished my goal.

Here is the bottom view.  The missing corner wasn't supposed to be that way. It chipped when I dropped the tester on the floor few years back.


And the top view. I used a small piece of a copper-clad PC board with a gap scrapped in the middle. I also tinned it so it doesn't tarnish.  That was soldered to one of the old battery terminals (strips of metal).  On the other side I soldered a 1000 ohm resistor between the other copper area and the other battery terminal. I also soldered a piece of wire as a lead for some awkward shaped LEDs.



Here is the complete unit. The tester is very compact and easy to use.  And with 9V and 1000 ohm resistor it will easily illuminate all LEDs and yet the current is limited to a safe level (around 6-7mA depending on the LED type).  I also usually use old batteries I take out of smoke detectors as they still have plenty of voltage for this tester.



 Here, I'm testing a T-1 size LED.


...and a SMD 0603 LED. I simply place the LED on the metal pads and it lights up. 

I've planned for a long time to build an "LED Evaluation" unit: a box with two rotary switches, one that taps various voltages, and one that selects one of a number of resistors. Mostly it would be used to decide what power supply would be best to illuminate various white LEDs such that they're bright without looking like supernovae. One of many moldy old round tuits. I have all the parts...

DKS, I laughed when I read your post!  Becasue I was going to post pretty much the same statement (down to having all the parts and it being a moldy old round tuits.

Mine will be slightly different. I will use an adjustable current source and have a digital voltmeter built-in, in parallel with the LED circuit (to give me its Vf at whatever current I set the tester for).  The current will be controlled by a rotary switch from 0.5-30mA.  Having a Vf and the current to get the brightness I need makes it easy for me to calculate the current limiting resistor for any power supply voltage.

[Ian MacMillan]

Figures.... I went to WalMart yesterday and the Conway one does not have these 

[Lemosteam]

Crap Ian, sorry.   

BUTTTT- Walmart has one of the best ship to store policies around.  You can purchase it online and have it shipped to your nearest walmart FOR FREE- called ship-to-store.  WORKS GREAT used it many times, cameras, computers, printers, lots of stuff.  If you decide you don't want the item they will give you a refund, no questions asked.

If that does not work, let me kknow I'll pick a set up for you!

[DKS]

FYI, these same lights are available at Home Depot. Same price, IIRC.

[Ian MacMillan]

FYI, these same lights are available at Home Depot. Same price, IIRC.

Roger. Checking...

[peteski]

I checked out the Martha Stewart lights at Home Depot. They do appear similar to the ones John found at Walmart but there were no warm white ones available. I looked over all the ones on the shelf and they were all either red or multi-color.  I am looking for the warm white ones.

[Lemosteam]

peteski, email and PM sent...  Fear not!  Ian, my offer still stands to you too!