G+_Peter Mucha Posted March 21, 2016 Share Posted March 21, 2016 Will this burn my house down? https://www.amazon.ca/gp/aw/d/B017YEOD6G/ref=mp_s_a_1_1?qid=1458524659&sr=8-1&pi=SY200_QL40&keywords=5v+20a+kitop&dpPl=1&dpID=51bzlg9EoLL&ref=plSrch Im looking to power about 9m of 30led/m ws2821b led strip. 20a will be plenty to run the leds and arduino. Im just not sure if these power supplies are safe to run for days at a time. What other alternatives for good quality power supplies are out there? Anything specific i should be looking for? Thanks for any info. https://www.amazon.ca/gp/aw/d/B017YEOD6G/ref=mp_s_a_1_1?qid=1458524659&sr=8-1&pi=SY200_QL40&keywords=5v+20a+kitop&dpPl=1&dpID=51bzlg9EoLL&ref=plSrch Link to comment Share on other sites More sharing options...
G+_610GARAGE Posted March 21, 2016 Share Posted March 21, 2016 I have a couple running that are like that (different voltage/amperage) nothing smoking yet. :) As long as you don't push them to close to the max amp draw, they should be fine. Link to comment Share on other sites More sharing options...
G+_Peter Mucha Posted March 21, 2016 Author Share Posted March 21, 2016 9m x 30led/m x 60ma/led = 16200ma or 16.2a and thats peak use, all white leds full brightness. Will this be enough beffer to ensure the 20a supply wont get stressed out. Link to comment Share on other sites More sharing options...
G+_Peter Mucha Posted March 21, 2016 Author Share Posted March 21, 2016 Also will having long wires to get to the led strips going to add to the draw on the power supply? I need to run about 20 - 25 feet from power supply to strip. I want to keep the power supply indoors. Link to comment Share on other sites More sharing options...
G+_610GARAGE Posted March 21, 2016 Share Posted March 21, 2016 Peter Mucha Yea, I would say that would be fine. Just make sure you give it plenty of ventilation. That's a long distance. I don't think that you would loose that much amperage across it. But you would need some really beefy wires. According to this chart, 8 gauge wire. http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted March 22, 2016 Share Posted March 22, 2016 8 Guage wire is pretty thick. Would it make more sense to run 24V to each light strip and regulate the voltage down to 5V from there? Link to comment Share on other sites More sharing options...
G+_610GARAGE Posted March 22, 2016 Share Posted March 22, 2016 Ben Reese A transformer would probably work better. Be a bit more efficient. But DC don't travel well. You could also get cheap wall wart adapters, or small 110 to 5v power supplies on ebay. Then just run 110 to each section. But I would assume that would mean having power supplies outside. Also, I should mention, you can't run these lights (comfortably) as one strand for that distance. I would tap in power at a couple of locations. They get really hot if you don't. Maby every 5-10 feet(1-3m). You could just parallel a wire along the lights and tap in too. Link to comment Share on other sites More sharing options...
G+_Peter Hanse Posted March 22, 2016 Share Posted March 22, 2016 +6110bob It is not loss of amp but loss of voltage. But also you should provide proper line protection just like you house has breakers to protect the lines from over current. If you want to use smaller gauge to each string of lights you would want to provide over current protection based on light string or wire size using which ever is less. Be careful stringing together many lights in series. You have to remember wire and conductors will take the current until they overheat. Max current through a wire is determined by how much heat the wire will produce at given current and if the insulation can Handel the temp. Running wire in confined tubes or bunched together will also reduce their max current. Having a good reference like Ugly's Electrical References will help. http://www.uglys.net. I think Home Deopt has them in electrical department. Link to comment Share on other sites More sharing options...
G+_Peter Mucha Posted March 23, 2016 Author Share Posted March 23, 2016 You guys are right, the logistics of running 20a around the deck. Im looking to have a high wife approval factor, so no huge cables. I'm thinking of running 24v. There are outdoor 24v transformers for lighting that are safe to use (or i can stay with an indoor power supply). Im thinking of having one power cable going all the way around the deck and tapping 1m sections of strip off the 24v main feed. I could then put a buck converter at the start of each section. I like this one: http://m.ebay.com/itm/DC-DC-3A-Buck-Converter-4-28V-24V-TO-1-20V-5v-12v-step-down-power-supply-Module-/331695257124 as it looks small enough that I can solder it and heat shrink it to the strip so it can be waterproof. What do you guys think, anything specific I should look out for in the converter? Most seem to have two capacitors and are bigger. What are the differences between them? Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted March 23, 2016 Share Posted March 23, 2016 That looks like it should work. And the price is good too. I looked it up on Amazon to see reviews thinking that it might get hot, but there doesn't really seem to be any mention of heat there. MP1584EN ultra Small DC-DC 3A power Step-Down Adjustable Module Buck Converter 24V To 12v 9V 5V 3V for Arduino By Atomic Market https://www.amazon.com/dp/B00WQ6V0F0/ Link to comment Share on other sites More sharing options...
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