BillMorton

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Led Christmas Lights

I was very excited to get my new LED Christmas lights today!

However when I first plugged them into the wall socket, I immediately noticed and was very bothered by the very fast flickering that was occurring. I realized that the manufacturer was using a simple diode, or half wave rectifier on the led’s. This results in only half of the AC sine wave being used, which is 60Hz, resulting in the LED’s flickering at 60Hz which is very very annoying (my eyes hurt after looking at them for a few minutes).

So I decided to remedy the problem by building a full wave rectifier, which through the use of four diodes, uses both sides of the sine wave to produce the DC current. Once I get a capacitor rated for 115v, I will put that on the DC line as well to clean up the remaining bumps in the voltage. The LEDs still flicker, but at an un-noticeable 120Hz. A proper capacitor will mostly eliminate the remaining flickering.
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  • This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

    This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

  • This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

    This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

  • This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

    This is my proto-board setup, measuring the voltage output of the full wave rectifier bridge

  • DC voltage being displayed on a volt meter. Once the capacitor is added this should be 115vdc.

    DC voltage being displayed on a volt meter. Once the capacitor is added this should be 115vdc.

  • 50% success =(

    50% success =(

  • 50% success.

    50% success.

  • Untitled photo
  • I realized that they made half of the LED's use one side of the sine wave, and the other half use the other side. This made only half of the string work when I provided it DC power. A simple splice to reverse the wires at the half way point fixes the problem.

    I realized that they made half of the LED's use one side of the sine wave, and the other half use the other side. This made only half of the string work when I provided it DC power. A simple splice to reverse the wires at the half way point fixes the problem.

  • I realized that they made half of the LED's use one side of the sine wave, and the other half use the other side. This made only half of the string work when I provided it DC power. A simple splice to reverse the wires at the half way point fixes the problem.

    I realized that they made half of the LED's use one side of the sine wave, and the other half use the other side. This made only half of the string work when I provided it DC power. A simple splice to reverse the wires at the half way point fixes the problem.

  • Completed splice for now.

    Completed splice for now.

  • 100% success! =)!

    100% success! =)!

  • To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). 

This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. 

This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

I also found out that exif data is only accurate to the second, so I had to sort the pictures by file name to get this sequence in the right order!

    To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. This set of photos demonstrates the maddening flickering that was going on before I resolved the problem. I also found out that exif data is only accurate to the second, so I had to sort the pictures by file name to get this sequence in the right order!

  • To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). 

This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. 

This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

    To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

  • To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). 

This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. 

This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

    To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

  • To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). 

This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. 

This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

    To demonstrate the flickering, I took a series of photos at 1/200th of a second (1/85 works too, but since I can only take 5 frames a second, 1/200th is much better at showing the effect). This is a normal strand plugged directly into the wall. Since half of the strand lights on the positive peak of the sine wave, and the other half lights on the negative peak of the sine wave the two halves flicker at opposite intervals at 60Hz aka 60 times per second. This set of photos demonstrates the maddening flickering that was going on before I resolved the problem.

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