LED Altoids Tester


Introduction: LED Altoids Tester

Altoids LED Tester with 2x AA Batterysupply made of old IDE Cable

Tools you need:

Altoids Gum Tin
Soldering Iron
wire cutter or caliper
Battery Clip for 2xAA batteries
2 AA batteries
1 old IDE cable

20min of your life ;)

By the way.. I was inspired by this awesome Instructable:


Step 1: Find Empty Altoids Can

I like the size of this one because it fits 2x AA batteries pretty well.
Besides the gum tastes delicious.
*But don't eat all at once..*

Step 2: Find and Dismantle the IDE Connector

If you have a IDE or Floppy Cable, simply dismantle the connector.
Now you should have just the connector with the pins on the back without the cable.

Step 3: Soldering the Pins

First make shure how many hole you will keep for testing.
I left 8 holes and cut the rest with a caliper.
In the picture i drew 5 pins each row (10 holes) depending on how you like it.
You can either cut first and solder afterwards, or solder first and have some grip and space to solder.
I prefer the second version.

Solder the pins on each side and be careful that you don't connect with the other Row.

Solder now the positive wire of you batteryclip to a 68 Ohm Resistor (just in case *thanks for the suggestions*) and connect to other end of the resistor with one row of the IDE Plug, the negative wire to the other row.

Step 4: Test and Glue

Before you glue everything together make shure it really works!
Once glued there is no way back!

I used red hotglue to match the color of the Altoids.
Keep the connector fixed until the glue is cold.

Glue the Batteryclip first, then fill up the empty space as you like.
Check the polarity of the LED(s) you connect.

Now you're good to go.

Have fun with it. I certainly do.



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    27 Discussions

    You can test if the leds you have laying around are working or not without having to solder them together

    The majority of my LEDs are about 3.1 and 3.2 Volts so this would be perfect.

    But I do have some like the yellow, orange and red ones that are about 2.1 -2.4 Volts

    Maybe if I make this I'll include a switch for supplying either 2 Volts or 3 Volts.
    Just need to add a resistor and a bit of wire and a switch as far as I know.

    1 reply

    just adding a resistor should do. since its just for testing the 3v LEDs won't be so bright with a higher resistor but you can cover almost any led for testing then..

    actually i made a joul thief for testing.. that works with just one battery.

    For step 3 you don't really have to solder, you can use a strand of the wire you took the plastic out of and push it into the little pins. If you use a knife to push the cable down further into the pin you get a more secure connection.

    1 reply

    Simply to determine if your led works or not. But I made a better one using a joul thief to use just 1 AA battery for a quick check.

    Thanks. I think I don't need a resistor for testing, plus it's only about 3V. Most of the LEDs (exept high power LEDs) work at about 3V. The blue one is not as bright as it could, but it will work. Correct me if I'm wrong ;)

    well, usually voltages: Red - 1.7 Bright Red - 2.0 yellow - 2.1 Green - 2.1or 2.2 blue or white - 3 volts or more (depends a lot) tell me, am I being mean? Ever since some of my instructables this one guy has been leaving super mean comments to me, and sometimes he right, but explodes stuff out of proportion, such as my sound reactive led instructable, saying I did everything wrong and insulted me, made me feel really bad. Even though I did adress all the stuff he said in my instructable...

    not sure what ur talking about cuz most of the leds i have (red,yellow,green,blue) work between 3 and 6 volts

    In my country a super-bright LED draws 20mA and used 3.3v while a normal LED draws ??mA and uses 9.3v. Weird, or what?

    no sweat. I don't have my master in electronics.. so I do like people telling me what to improve. I think that's what instructables is for.. so thanks for your advice. What resistor do you suggest?

    i would personally suggest (if you make a new one) to put a current regulator regulated @ 5mA. most L.E.D.s work at 20mA, but there are exceptions, like 5mA and 3mA and sometimes, more, but that is the most common. 20mA L.E.D.s @ 5mA are still bright and 5mA L.E.D.s are as bright as they go... 3mA L.E.D.s would be in a bit of a risk (very very little) and you do it for a little bit of time, 2 or 3 seconds, since its a tester... i personally suggect the LM317 current/voltage regulator, 'cause its really easy to use. if there are any questions about what i said, dont be shy to ask. -gamer ps. very nicely made instructable!

    thanks. I think i prefer the regulator instead of the resistor.. cause you never know the exact voltage of the LEDs (I have a jaw with leds soldered out of various things e.g. printer, keyboard.. everything i could get my solder iron on )

    I have to make shure the 20mA are still bright - as you said.. would be sad if you can barely see anything like the LED tester on my Multimeter..

    a 20mA L.E.D. at 5mA is very bright concidering it is using 1/4 of the mA's needed. do your tests and tell me your results, but i do know i got great results... anyways... good luck -gamer

    You can calculate it:
    R = (U - Uled) / I
    R is the resistance
    U is the voltage from the Batteries
    Uled is the voltage the LED needs
    I is the current the LED needs
    in your case: R = (3 - 1.7) / 0.015 = 1.3 / 0.015 ~ 86 Ohm for a red LED.
    mfg Daniel

    thanks. it's not that i don't know how to calculate it, but how much do I need...
    maybe your example makes sense, cause it's almost the lowest LED Voltage it could get..
    I'll see if I open it up again someday to keep the nice altoids tin
    and then decide to put either the regulator or the resistor in the circuit.

    .. by the way.. here is a sweet online calculator: http://ledcalc.com/ VERY useful