KCLeblanc Posted July 26, 2016 Share Posted July 26, 2016 I've was looking at cheap DMX controller for LED tape on ebay. Stuff like this. http://www.ebay.co.uk/itm/8CH-RGBW-DMX512-Decoder-Controller-2groups-RGBW-Output-DC5V-24V-for-Led-Strip/142003080818?_trksid=p2045573.c100507.m3226&_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D20151016114640%26meid%3D990dd9c656634f76871aa4d0971a3328%26pid%3D100507%26rk%3D1%26rkt%3D1%26 And it got me wondering since they basically convert DMX into a low variable DC voltage, could one be used as a Demux. Link to comment Share on other sites More sharing options...
DrV Posted July 26, 2016 Share Posted July 26, 2016 Almost certainly not - dimming LEDs (tape or big LEDs in lanterns) is pretty well universally done using pulse width modulation. I suppose you could add some electronics to the output to create a variable voltage but that would be a bit daft. Better to get the right unit in the first place Link to comment Share on other sites More sharing options...
timsabre Posted July 26, 2016 Share Posted July 26, 2016 Actually most demuxes use pulse width modulation too, smoothed by a capacitor, to make the analogue voltage. But you need to add an op-amp buffer per channel to drive the dimmer. If you like making electronics then it would work. Link to comment Share on other sites More sharing options...
IRW Posted July 26, 2016 Share Posted July 26, 2016 Short answer, yes, with difficulty! I tried for a project a while back (there is a thread somewhere on here about it), but in the end gave in and bought some purpose designed circuit boards, so I can say with personal experience it would be much easier to just get the right thing for the job. What is the application you are applying it to? A whole rack of dimmers or single packs? In my case I was building custom 6-channel demux cards for Betapacks. Ian Link to comment Share on other sites More sharing options...
KCLeblanc Posted July 26, 2016 Author Share Posted July 26, 2016 A whole rack of dimmers or single packs? In my case I was building custom 6-channel demux cards for Betapacks. Ian It was more theoretical then that, I was literally looking at one on ebay and the idea popped into my head. Link to comment Share on other sites More sharing options...
graemeftv Posted July 27, 2016 Share Posted July 27, 2016 yes its very easy if all you need is 0 - + 5v all you need as a capacitor to smooth the pwm output from the chip and remove the mosfet however if you need 0 - + 10v then you need am op amp with some gain etc. if you want to use one to drive an analogue dimmer its possible with out the extra op amp. pm me if you need advice on how to fit one into an old dimmer Link to comment Share on other sites More sharing options...
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