I have: 11-12 meters of RGB 5050 LED strip, which consumes 14.4W per meter, seller says I should use 12V DC 180W 15A power supply, to power the whole thing up. I also have 3x MOSFET-N (IRLZ34N) I want to connect the strip to my digispark (as an alternative for arduino) to control its colors. Will it be safe to connect them as pictured below?
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\$\begingroup\$ The printed circuit traces on LED strips will not be able to carry the current to power much more than 10 metres of strip, and even at that length, you will have very noticeable voltage drop. You should feed them separately, in the middle, or with parallel feeder wire. Figure 0.4 amps per metre per channel. If in North America or Philippines I would use 14 AWG wire; while a thinner wire would suffice, 14 is dirt cheap since it's widely used in housing and architecture. It also comes in cables with 2-4 conductors and a ground wire. \$\endgroup\$– Harper - Reinstate MonicaCommented Jun 18, 2017 at 17:21
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\$\begingroup\$ the actual circuit itself seems fine. @Harper: is 10m the rule for RGB as well as white? (rgb has twice as many traces as white to share the current) \$\endgroup\$– dandavisCommented Jun 18, 2017 at 20:14
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\$\begingroup\$ @dandavis It isn't the number of traces, it's the width - RGB traces are half as wide since there's 4 of them. (and all of it comes back on the common). White (i.e. 3528) also have 1/3 the amperage per metre, at typically 0.4A per metre, so they are asking less of their wider traces. \$\endgroup\$– Harper - Reinstate MonicaCommented Jun 18, 2017 at 20:57
1 Answer
It seems to me that you are going to use a white bread board for such a circuit and I'm not recommending doing that at all due to the huge amount of current intended to power up your LEDs. And I would recommend that you design your circuit on a stand alone PCB to consider the relationship between applied current on tracks and track width. Also I would recommend using Heatsink (TO-220 Package) to allow your MOSFETs drain some of the heat generated from them to avoid their failure.