Salvage Many LEDs From Scrapped LED Strips

LED strips are very popular and so beautiful. They come in different colors and can be easily used.

Some LED strips can be powered by 220 volt or by 12 volts.

In both cases they give cool and beautiful surrounding lighting effects.

But unfortunately, they can be easily damaged and become useless. You need to replace large pieces of these strips when damaged.

As we can see, there are damage in only small piece of these strips and not in all of it. When you see damage in one LED, one resistor or one lead of power lines we feel upset that the whole part of the LED strip cannot be used because of that damage in that small part.

We also feel the urge to get some good LEDs from that LED strip.

I had some of these damaged LED strips and hoped to make something useful from them.

Today I figured out how those LEDs strips are connected and how I can salvage many LEDs in good condition to reuse them (today project) or to repair those LEDs strips (in future projects).

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Scissors

Each LED strip is constructed by repetitions of one meter building blocks.

LEDs are connected in series by thin copper film strips. The LED strip has two power lines on each side and they carry the high current (connected to 220V ac mains). Each meter of LED strip is separate from other parts.

Each meter contains about 30 SMT LEDs and some SMT resistors.

Each meter is connected from its both ends with the side power lines.

On one end of the LED Strip meter piece one of the side power lines is connected to the LED positive terminal by solder point. On the other end of the LED Strip meter piece the other side power line is connected to the far end LED negative terminal by another solder point.

That construction makes each meter independent from other parts of the LED strip.

Any meter piece of the LED strip can be damaged for many reasons. If any LED, resistor or power line.

This can be due to normal LED or resistor life time or due to corrosion in power lines. This damage makes the whole meter block useless.

LED Strips

Scissors

Soldering iron

Microwave oven turntable motor

LEDsWe choose some LEDs that we can see they seem to be in good condition (no apparent damage or corrosion).

We must choose some number of LEDs with at least one resistor to limit the current in the LEDs.

Then we cut the strip using scissors. We cut the rubber cover parallel to the strip on both ends on both sides. That makes four places to cut on the rubber strip. And also makes four power lines terminals(two on both sides)

Connection

Use soldering iron to solder one of the power lines to one LED terminal. You can see three small terminals on each LED you can solder on them.

On the other end of the piece of LED strip you just cut you solder the other power line to the far end LED terminal.

Connection of the power source

Caution:

The Microwave motor is a simple permanent magnet motor but it has a reduction gear set that makes it slowly rotate when powered by the 220v ac mains to turn the plate in the oven.

This reduction gear set makes that motor rotates very fast internally if you turn it with your hand. This generates high voltage (about 500 v). This voltage is not lethal because it produces very small current but it really hurts.

So, make sure not to touch the microwave motor terminals.

For more info about the microwave motor see that instructable and video.

Connect the microwave oven motor to the power lines on one end.

Now we can test the strip by turning the microwave motor knob and see the LEDs light.

Now we connect each power line from one end to the other end of the same power line. This makes the strip looks like a bracelet.

Now you can test the LED light in any place and see its light.