Huzzar Posted February 26, 2008 Share Posted February 26, 2008 Hi all, Was wondering if anyone knew where to get/how to make a 12v LED dimmer? I have found hundreds of products that take 230v and output 12v with some form of dimming, but nothing that has 12v input and certainly nothing that takes DMX. Any suggestions? Link to comment Share on other sites More sharing options...
pritch Posted February 26, 2008 Share Posted February 26, 2008 Is this any use? http://www.hoelscher-hi.de/hendrik/english/led.htm Link to comment Share on other sites More sharing options...
back_ache Posted February 26, 2008 Share Posted February 26, 2008 you have to have a bit of a hacker mentality to want to modify the low voltage side rather than get a unit that is a psu and dimmer combined, so the market moved away from it however they are still available here are some options:- http://dynalite.eu/content/led.htm Link to comment Share on other sites More sharing options...
gyro_gearloose Posted February 26, 2008 Share Posted February 26, 2008 Heres a pic of an LED tile that I'm working on at the moment (sorry about the picture quality, but you try photographing somethng black, in low light, with a crap camera :( ): http://i157.photobucket.com/albums/t41/gyro_gearloose/ledtile-1.jpg Its 480mm wide by 240 mm tall, with a pixel pitch of 60mm. Its meant to be part of a larger wall which can be assembled in any configuration. The LEDs are pale blue only but this means that I can have 512 pixels per DMX universe, so I can have 16 tiles per universe. The LEDs are driven by 2 TLC5940 driver chips. These chips are controlled by an Arduino clone. Each tile is then connected to a hub which looks after reciving the DMX data and sending portions of it to each tile. Link to comment Share on other sites More sharing options...
Wol Posted February 26, 2008 Share Posted February 26, 2008 Heres a pic of an LED tile that I'm working on at the moment (sorry about the picture quality, but you try photographing somethng black, in low light, with a crap camera :( ) That looks cool. About a year ago I made a set of 8 LED Birdies running from a PIC and a couple of darlington drivers. Used a computer power supply though, as if you multiply up the number of LEDs I had, by the forward current for each LED, it needed a computer PSU to give enough current to it! Depending on how many LEDs you need to drive, a bog standard 12V psu will give enough current. DMX can easily be coded on a Microchip PIC, if you have any knowledge of these, or someone you know who does. Microchip (annoyingly) released code as an application note to do DMX transmission and reception... about a few weeks after I'd written mine. Gr! But this can be used to save the farce of receiving the data. Basic PWM / or whatever artistic licences alternative to PWM is in the big copyright farce with someone trying to patent PWM for LED dimming (look on the blue room wiki, I think theres links there). How many LEDs do you need drive? What sort of application do you need them for? Link to comment Share on other sites More sharing options...
scottmcleod Posted February 26, 2008 Share Posted February 26, 2008 Heres a pic of an LED tile that I'm working on at the moment (sorry about the picture quality, but you try photographing somethng black, in low light, with a crap camera :( ): Its 480mm wide by 240 mm tall, with a pixel pitch of 60mm. Its meant to be part of a larger wall which can be assembled in any configuration. The LEDs are pale blue only but this means that I can have 512 pixels per DMX universe, so I can have 16 tiles per universe. The LEDs are driven by 2 TLC5940 driver chips. These chips are controlled by an Arduino clone. Each tile is then connected to a hub which looks after reciving the DMX data and sending portions of it to each tile. I would like more details on this project... It is relevant to my interests... If you might? Hi all, Was wondering if anyone knew where to get/how to make a 12v LED dimmer? I have found hundreds of products that take 230v and output 12v with some form of dimming, but nothing that has 12v input and certainly nothing that takes DMX. Any suggestions? http://store.lightorama.com/cmdedcca.html120$ = 16 up to 12VDC dimmable channels. Packs may be daisy chained up to 512 channels IIRC. + their DMX > LOR converter which is being released soon. Contact the manufacturer for more info. = 512ch of DMX LED's! Link to comment Share on other sites More sharing options...
gyro_gearloose Posted February 27, 2008 Share Posted February 27, 2008 Ok. What do you want to know? I originally looked at using just a Parallax Propellor as the central 'hub' that could drive all of the tiles. Each tile at the time was just a 4x4 grid of pixels, driven by one TLC5940 chip. Heres a pic : http://i157.photobucket.com/albums/t41/gyro_gearloose/originaltile.jpg Its 520mm square and is built using nothing more than 65mm square plastic drain pipe! You may notice that there are three LEDs in each 'pixel'. They are just three blue LEDs in parallel. The plan was to use some sort of diffusion material to cover each hole so that each pixel appeared as a solid circle and not just three points of light. Unfortunately while it all worked with really short data lines, as soon as I tried using just a 2 metre cable there was so much interference introduced that the LEDs just flickered or sometimes didn't light up at all :( . A few people on the Parallax Propellor forums suggested using balanced twisted pair hardware to solve the problem, but it would have been quite expensive compared to the rest of the system. While I was Googling for ideas, I found this article on the Arduino website. A quick look on the Farnell website showed me that the price of the parts for a simple Arduino clone would only cost a few pounds. Another benefit is that since the code accepts a text string from a standard serial interface, anything with a serial port could control the tiles. In fact, the prototype I built is connected to the serial port of my PC. Link to comment Share on other sites More sharing options...
Wol Posted February 27, 2008 Share Posted February 27, 2008 The plan was to use some sort of diffusion material to cover each hole so that each pixel appeared as a solid circle and not just three points of light. I'd guess a similar thing to the Chroma Q pixelcaps: http://www.aclighting.com/images/lighting/products/chroma-q/big_pics/pixel_caps.jpg The disco dance floor project also looks quite interesting. Based on the atmega chip, along with the Maxim LED driver, I expect it wouldn't be too hard to incorporate DMX into that. Link to comment Share on other sites More sharing options...
peternewman Posted February 27, 2008 Share Posted February 27, 2008 Along the lines of some of the more recent posts, I'll recommend the stuff Response Box have been making. Its amazingly cheap (about £5/pixel) and each pixel has full DMX control. I believe he's also working on a range of boards with just the LED dimmer, or you could get the boards and unsolder the LEDs, they run on 12v too. Link to comment Share on other sites More sharing options...
Steve.m Posted October 29, 2008 Share Posted October 29, 2008 On the subject of LED's and dimmer's, does anyone have or know where I can get a circuit diagram for a 3 channel PWM DMX controller for use with LED (RGB)?Moderation: Please don't post the same question twice - I've merged the responses from the other topic into this one Link to comment Share on other sites More sharing options...
boatman Posted October 29, 2008 Share Posted October 29, 2008 :P knows. http://www.milinst.com/DMX/dmxside.htm Link to comment Share on other sites More sharing options...
dbuckley Posted October 29, 2008 Share Posted October 29, 2008 Look here: http://www.brilldea.com/ Link to comment Share on other sites More sharing options...
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