ultra Posted April 15, 2007 Report Share Posted April 15, 2007 i'm not sure where to begin looking on this one.my sequencer works but only for a short time. anywhere from 10 seconds to a minute into using it, it randomly reboots itself.i've tried disconnecting each set of buttons/encoders one by one to see if the problem comes from a short or something and i get the same results every time. sometimes when i start it up it doesn't completely boot. it just kinda hangs there.any ideas? Quote Link to comment Share on other sites More sharing options...
lylehaze Posted April 15, 2007 Report Share Posted April 15, 2007 Is the 7805 getting hot?Careful, it might be hot enough to brand your finger.Good Luck,LyleHaze Quote Link to comment Share on other sites More sharing options...
ultra Posted April 16, 2007 Author Report Share Posted April 16, 2007 yes it is. i'm running it at 9v and it gets quite hot. i figured it should be. what can i do? i'm not sure it's a heat issue because the sequencer kinda acts funny in general.edit: what's strange about this is that i can run the default sequence just fine and it doesn't reboot. it happens when i start messing with buttons and/or encoders.if i had a wonky encoder, could it cause this problem even if i didn't touch it?edit again: this is really strange, but the sequencer seems to be shutting down when i have 10 or more steps active. usually it's around 12 but i've counted 10 and 13, and it always shuts down as soon as i'm turning on a step. ???i'm going to try the new software. i just have v2 loaded right now because i'm just testing things out. but i'd imagine that this is not a v2 related bug so i'm guessing i'll end up with the same results.edit: it won't allow me to upload v3.1. it gets an error and aborts the upload. i didn't have this problem earlier when installing v2 software. midi io 128 software uploads just fine. Quote Link to comment Share on other sites More sharing options...
doc Posted April 16, 2007 Report Share Posted April 16, 2007 yes it is. i'm running it at 9v and it gets quite hot. Please spend your regulator a heatsink.I don't know how much current your seq soaks. Do you have two backlit LCDs?The problem sounds to me like a typical undervoltage problem, caused by the regulator.If your seq needs to much power the regulator is getting very hot. If it's getting too hot and/or the current is too high, the regulator puts the output voltage down.Please measure after the regulator the voltage and tell me the value before the seq resets.Also interesting would be how much current your seq soakes out of the regulator. Are you able to measure the current?It might be zhat your problem is solved with a heatsink. It also mught be, that your powersupply isn't strong enough. What type of power supply you are using?but i'd imagine that this is not a v2 related bug so i'm guessing i'll end up with the same resultIt isn't a bug. It could have two possibilities: Power consumption/low voltage or a reset caused by a short.greetsDoc Quote Link to comment Share on other sites More sharing options...
ultra Posted April 16, 2007 Author Report Share Posted April 16, 2007 my ac/dc adapter is 500mA and set at 9v (switchable). i do have two backlit lcds. i just tested it without the dout module connected and that indeed solved the problem, so you're right about it being power consumption. any idea what kind of heat sink i'd need for this regulator?i'm not so sure about how to test current, but i can try to figure it out. which pin on the regulator would i measure voltage from? would i use that temporary ground on the core for testing too?thank you.drew Quote Link to comment Share on other sites More sharing options...
Lall Posted April 16, 2007 Report Share Posted April 16, 2007 Hi Drew,I think it would be wise to take a look at the datasheet of the LCDs you have. The ones I have consume 560mA which is a hell of a lot.When you take two of them, you already consume about 1A for the backlight...If yours are consuming a lot as well, you may consider changing your ac/dc adapter for a more powerful one because 500mA at 9V is not so strong. Best regards,Lall Quote Link to comment Share on other sites More sharing options...
doc Posted April 16, 2007 Report Share Posted April 16, 2007 500mA with two backlit LCD is perhaps really not enough.But if your backlights and the rest together exceed 1A your regulator is also not capable of handling that much current.Please measure your current:Plug your multimeter to DC current (or DC A) - if your power supply outs DC (otherwise AC!) . Put one wire between a pin of J1 and the the other wire to the unsoldered lead of the power supply. In other word: You have to connect your multimeter in series with the powersupply. multimeter + -PS o--------o o-------oJ1PS o------------------oJ1If your power consumption exceeds 500mA then you need another powersupply with at least 1A.If your power consumption afterwards exceeds 1A you'll have to replace your regulator with a 2A - type. I think it's called µA78S05 .In every case you'll need a heatsink. You can unmount the regulator and mount it on the bottom of a metal case (if you use one) or you can buy a small heatsink for a TO220 housing.Please test also, if there is no fault on the DOUT board:Connect everything together but disconnect the backlight of the LCDs. Then your 500mA powersupply should be enough and no reset should happen. If you still get resets, than your DOUT is faulty.hope this helpsgreetsDoc Quote Link to comment Share on other sites More sharing options...
ultra Posted April 17, 2007 Author Report Share Posted April 17, 2007 thanks for all the help. i went and got a 9v, 1500mA power supply and it doesn't shut off anymore. with all steps active, pulling the most current, it sits at about 580mA. do you think this is enough to require a heat sink? if so, do you know a part number for a heat sink that fits with the voltage regulator that came with the core module (smashtv's kit)?thanks again!drew Quote Link to comment Share on other sites More sharing options...
lylehaze Posted April 17, 2007 Report Share Posted April 17, 2007 If you have a metal case, you might try something like this:http://www.midibox.org/dokuwiki/lib/exe/detail.php?id=midiboxmixerhardware&cache=cache&media=psandcore.jpgDon't look at the core regulator, look at the two on the power supply in the middle of the picture. I'll probably change the one on the core over too, eventually.The tab of the 7805 is at "ground" potential, so just mount it off the bottom of the board, and you can use your case as a heatsink. Note that I sanded the paint off there, I used a dab of thermal paste, and I did NOT do this with the negative regulator, as its tab is not at ground level.Have Fun,LyleHaze Quote Link to comment Share on other sites More sharing options...
Lall Posted April 17, 2007 Report Share Posted April 17, 2007 Hey,I would definitely advise you to add a heatsink or use the metal case as heatsink as mentioned by Lyle.As you have a 9V DC input and an 5V DC regulated output, the regulator will see a difference of 4V at its pins.When you draw 580mA from the regulator, it has to dissipate 4V * 580mA which is 2.32 Watts.If you look for example at the datasheet of the KEC 7805 on this page: http://www.datasheetcatalog.net/datasheets_pdf/7/8/0/5/7805.shtml it says that the regulator can handle 2Watts without heatsink.Such information is not always available (in these terms at least) from datasheet but I believe 2.32Watts is too much for a 7805 without a heatsink so I would go for one or for Lyle's solution.Best regards,Lall Quote Link to comment Share on other sites More sharing options...
ultra Posted April 17, 2007 Author Report Share Posted April 17, 2007 does anybody have the part number for the heat sink? Quote Link to comment Share on other sites More sharing options...
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