Meteor lights with cheap, non isolating, potential death trap transformers

videoman3857

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Apr 21, 2016
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Glass House Mountains
Last Christmas display we had a handful of snow fall /meteor shower lights that were the talk of the display in the seated refreshment area.
On Friday, to my pleasure, saw the delivery of 30 more of aforementioned lights that I ordered off E-bay for a quarter of the price I paid for the ones on display.
These units were supplied with a "USA" plug in transformer and despite me telling the supplier that I did not want the "USA / Australia power adapter" they sent them anyway. My intention is to use a 5V psu to supply power to this number of lights. - so much easier than power boards and leads all over the place.
I also had in my mind the need to "Extend" the leads so I can distribute the power from a central point.
The lights themselves seem to be well constructed. The light lead connects to the transformer via a 2 prong screw together pigtail type connector. The distance between the first tube of leds to the transformer is a mere 30cm.
How the manufacturer expects one to display the lights and keep the transformer out of the weather i will never know.
That being said, I have no real issue with the length of the cable as I was going to extend the cable length anyway.
Remembering that I read somewhere else that some of these cheap Chinese manufactured transformers are dangerous as the do not isolate the 240 ac power from the 5 volt dc side, I decided to pull one apart. Low and behold.
The transformer is just that - a cheap, no isolating, sub standard potential death trap.
Visiting David_AVD new store, I stumbled accros the same thing - though Davids post was about coloured meteor tubes.
I "liberated" a copy of his photo of the said type transformer to show / remind you of these poorly designed transformers.transformer.jpg dodgy_led_psu-240x300.jpg
 
Over the last couple of years I have bought a number of sets of these from different eBay sellers, all of the 5v variety although I have seen some mains voltage powered and some solar. The power supplies I have received have all been US flat pin or Euro round pin types, some with SMPS and some capacitive dropper, doesn’t matter, they all went in the garbage bin.
I joined a heap of sets together and power injected along the string and used a buck converter to power. The main issue I have is water ingress from the top caps, I noticed that some were going rusty so I ended up taking the bottom caps off the ones that leaked. The moisture didn’t seem to affect them overly.
 
Yeah, I put heatshrink around the top of the tube, filled with silicone and shrunk them to force some of the silicone out. That seemed to seal them well enough.
 
Yeah, I put heatshrink around the top of the tube, filled with silicone and shrunk them to force some of the silicone out. That seemed to seal them well enough.

I had moisture inside the ones I used at Christmas.
I could't make up my mind if it was water ingress from the rain or condensation forming from the heat/direct sun on them.
Either way, I ended up drilling a hole in the bottom of the tube to let the water out.
I think I might try David's idea of the heatshrink and silicone on this new lot. :thumbsup:
 
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