Test Tweezers for SMD-LEDs

I rarely work with SMD LEDs, but I quickly realized that's not easy, to find the polarity, and without putting them under power, you will never know the light color.

So I quickly built me this tester. It's just a CR2032 battery between two parts of wood or plastic. To conduct the electricity I took a self-adhesive copper tape.

Step 1: Quick Cad Draw

I use Qcad to draw the parts needed. I imported them to Inkscape to send the file to the laser cutter.

Nice clean parts, for a quick helping tool

Attached to this step the svg and dxf files

Step 2: The Parts

• 3mm - 3.5mm MDF or Plexiglas

• three screws M3 12mm

• three nuts M3

• Self-adhesive copper tape

• Adhesive tape

• One CR2032 battery

Step 3: Mounting All Together

Cut 2 stripes of copper tape. As seen on the picture, make sure, that the tape does not cover the screw holes, otherwise you will get a short circuit.

Now remove the protective paper, and glue the copper on the inside of the two parts.

Use some tape to insulate the middle part of the copper. Do not cover the two extremities.

Take the three screws and pass them through and place the round part. Place the Battery (Check the polarity!)

With the 3 nuts, screw the last part of it and finished. As you can see, it does the job.

Step 4: More Than Expected

You can even check normal LEDs with this SMD-LED Tester. Not bad for a tool, developed and built in less than an hour.

Hopefully this instructables was useful.

Comments

[marcelhebert]

Great idea. I would add an LED in series on one of the legs for when you short the ends together it won’t short out the battery and the LED can act as a power on indicator.

[axis2017]

Wont work, voltage drop too high with LEDs in series for 3.7V battery.

[nlohr]

I added a 100 Ohm SMD resistor (0603) in series. Most LEDs work with 1-20 mA and between 1.5V (red) to 3.2V (white). In the worst case, when both ends are occasionally shorted, this small resistance preventes a short-circuit, flowing only 3.0V / 100 Ohm = 0.03 = 30mA through the battery and contacts (battery = CR2032, which has about 3.0V with about 200mAh "power").

[Vickbo57]

Finally, thank you very much. Great job !

[tamal_patra]

What i sense just looking at the picture is: being speechless....
Take a bow, Sir.

[InsomniCAT]

Sir, you are a genius.

[Tinker-Bel]

Nice one!

[marderchen]

Hi, intresting Idea :3
Maybe build in simple circuit: additional taster powering a coil over transistor for having AC puls output for testing LED in booth ways have fun =^.^=

[АхмедА]

A simple and great idea

[davidhalfpenny]

I feel a Resistance Soldering tweezer coming on . . .
Thanks for the inspiration.

[onetruegod]

Well done! What a great idea.

[2hess]

Ingenious, awesome and brilliantly simple - and it can also test any other LED.

[Henmarsh]

What a clever but simple idea that will save me considerable frustration!