k6ccc Posted January 16, 2018 Share Posted January 16, 2018 A year or so ago there was a discussion (that I could not find) about how hot does a SanDevices E1.31 controller get in operation. I said that I have access to a thermal imaging camera and would make some tests next time my pixel tree was set up. Finally had time to do the tests this evening, so here are the results. For starters, here is a visible light photo of one of my E682 controllers mounted in it's 8x8x4 PVC electrical box. For those not familiar with the E682 controller, the green cable is plugged into the Ethernet module, the big IC in the top middle is the Propeller CPU chip, and there is a voltage regulator to the right of the lower right corner of the CPU. Below that are the various driver chips and then the 16 output connectors. At the bottom are the 16 yellow fuses for the power to each output. On this controller, the 12 strings of the tree are the 12 rightmost connection. Each string is drawing about 1.4 amps. Outputs 1-2 through 1-4 on the left are feeding my pixel star which has 90 pixels on each output. The three pixel star strings average about 2.4 amps. I found that I had to provide some power injection for the star when I built this last fall, so output 1-1 is feeding power to the far end of all three star strings. That one output is carrying about 2.7 amps.. This totals about 26.7 amps for the entire tree and star. This was lower than I expected, so I measured the voltage at the power inlet to the E682 and found 4.55 volts. The power supply output was 5.05 volts, so I had 0.5 volts of drop in the wiring from the power cables. The cable was originally two five foot runs of 10 AWG stranded copper wire in parallel for plus and two runs of the same wire for minus. After two years I moved the tree a bit and had to extend the cable, so I added three seven foot runs of 12 AWG stranded copper in parallel to the end of each set of 10 AWG wires for a total distance of 12 feet. Granted that all pixels on at 100% white for 15 minutes is an extraordinary situation, so I'm not overly worried about the voltage drop. These tests were performed about 3 hours after sunset and the outside temperature was about 60 degrees F. The temperature scale on the right side of the image is important as the board warms up. Next up is IR photo taken prior to applying power to the controller. I found it interesting that the Ethernet module was the coldest. Next up was this photo taken about 20 second or so after power was applied. You can see that the Ethernet module, center of the CPU, and the voltage regulator have started warming up. The next photo was taken about 15 seconds after turning all 870 pixels on to full 100% white. You can see the fuses and power connections warming up. Time: 01:00 The fuses and power connectors for the first four outputs in particular are warming. Time: 02:00 Time: 03:00 Notice that the temperature scale has gone up quite a bit. Time: 04:00 Time: 05:00 Time: 06:00 Continuing to get hotter. Time: 07:00 Time: 08:00 Time: 09:00 Thirty degrees above ambient temperature. Time: 10:00 Time: 11:00 Time: 12:00 Time: 13:00 Stabilized Time: 14:00 You can clearly see that the lower left part of the board gets the hottest. Although this is quite a bit warmer than ambient, temperatures in the mid 90s is hardly any concern. I hope you enjoyed this little diversion... 2 Link to comment Share on other sites More sharing options...
jerry72 Posted January 16, 2018 Share Posted January 16, 2018 I do not have a camera like that, but this last year i used my thermal gun, small red dot, our ambient temp at the time was about 45, hotes i registered was 75, full on white. The PSU's got up to 90 however. This year i plan to put in a vent with a thermostat hooked to a fan. Link to comment Share on other sites More sharing options...
k6ccc Posted January 16, 2018 Author Share Posted January 16, 2018 Interesting about your power supply. Mine hardly warmed up. I did take one IR photo of it about 10 minutes into the test but had not posted it. The only part that got very warm was the terminal strip. Link to comment Share on other sites More sharing options...
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