Marteen Posted February 18, 2009 Share Posted February 18, 2009 If you want moonlights you could get one of those arrays off of ebay for moonlights. You could build your own array with some small 1w LEDs as well, but it would probably be cheaper to purchase a premade one. Link to comment
Ryan110484 Posted February 22, 2009 Author Share Posted February 22, 2009 Is anyone using a combination of white and blue LEDs for moonlighting or just blue? Would adding white have any positive effect? give it a weird color? Should I just stick with all blue for moonlight? Link to comment
Ryan110484 Posted February 23, 2009 Author Share Posted February 23, 2009 evil- I think you are the only one with this experience, but if anyone else has done it I would appreciate your input as well. I have surface mounted rebels onto pcb's already and was planning on ordering the stcs1 chips today. How much harder would you say is it to surface mount them compared to the rebels? Hopefully pretty similar, but I doubt that. Link to comment
Ryan110484 Posted February 23, 2009 Author Share Posted February 23, 2009 anyone have any input/thoughts? Link to comment
evilc66 Posted February 23, 2009 Share Posted February 23, 2009 Difficulty will be the same. I'll get back with you on the setup when I have a little time this evening. Link to comment
Ryan110484 Posted February 24, 2009 Author Share Posted February 24, 2009 Difficulty will be the same. I'll get back with you on the setup when I have a little time this evening. Sounds good I'll be patient. Link to comment
evilc66 Posted February 24, 2009 Share Posted February 24, 2009 STCS1 has a thermal pad on the under side of the chip that has to be connected to a pretty decent amount of copper for heat removal. A common trick is to fill all the unused space of a pcb with the grounf plane, and attach the thermal pad to that (it's tied internally to ground so you don't have to isolate it). You won't be able to run much on that chip without the thermal pad attached. Link to comment
Ryan110484 Posted February 24, 2009 Author Share Posted February 24, 2009 STCS1 has a thermal pad on the under side of the chip that has to be connected to a pretty decent amount of copper for heat removal. A common trick is to fill all the unused space of a pcb with the grounf plane, and attach the thermal pad to that (it's tied internally to ground so you don't have to isolate it). You won't be able to run much on that chip without the thermal pad attached. Does the PCB you linked to on ebay have the capability to dissipate the heat if I were to mount it the PCB onto a heatsink as well? I changed the drivers to 750 for the blues and 1000 for the whites with six LEDs on each. The array worked out better being ran off of a 24v PS Link to comment
evilc66 Posted February 24, 2009 Share Posted February 24, 2009 The pcb would have to be modified to tie into the thermal pad. A heatsink could be epoxied to the top if there wasn't any parts blocking the surrounding area. Link to comment
Ryan110484 Posted February 24, 2009 Author Share Posted February 24, 2009 The pcb would have to be modified to tie into the thermal pad. A heatsink could be epoxied to the top if there wasn't any parts blocking the surrounding area. As in the top of the chip? I never even thought about the thermal characteristics of the drivers..... Do you think it would just be better to go with something else? I can do the surface mount, but I can't make a PCB that would have a heatsink attached to the middle of it for the chip to go on.... Link to comment
evilc66 Posted February 24, 2009 Share Posted February 24, 2009 The heatsink would attach to the chip, not the pcb. The STCS1 isn't the only option. If you don't feel it will work for you, there are tons of other options. The STCS1 is the most simple in terms of support parts. Link to comment
Ryan110484 Posted February 24, 2009 Author Share Posted February 24, 2009 Are the other options about the same cost wise? If they are going to get up towards 10-15 I would rather just buy buckpucks. The whole reason I wanted to do the chip was to save 10 bucks a driver. I'm open to any suggestions you have however. Lay it on me! Link to comment
evilc66 Posted February 24, 2009 Share Posted February 24, 2009 The STCS1 is the most affordable solution right now. You will either have to accommodate the design, or move to a different setup. Link to comment
Ryan110484 Posted February 24, 2009 Author Share Posted February 24, 2009 Found this- http://www.zetex.com/3.0/pdf/zxld1360.pdf Haven't had time to read the whole thing, but I haven't found anything on attaching it to a heat sink or any thermal pads. Its still surface mount, but I can deal. Link to comment
Ryan110484 Posted March 11, 2009 Author Share Posted March 11, 2009 Has anyone successfully designed/built there own LED driver? I've been looking into the zetec chips, but don't think I can build my own PCB for it. If anyone has managed any step by step or pictures would be appreciated. I think I might just switch to buckpucks, but I find them way too expensive however sometimes the money is not worth the headache. Link to comment
evilc66 Posted March 11, 2009 Share Posted March 11, 2009 I have built transistor based linear drivers, and switched capacitor buck drivers (STCS!). All have been on protoboards for now. I have been looking at the Zetex driver, and it seems interesting. The 1.25v reference for the dimming control is a pain if you want analog control, but seems painless for digital. Look at Eagle Cadsoft for board design. Basic version is free, and there are lots of guides on the web to show you how to use it. If you can make the board single sided, you can etch your own if you don't want the cost of getting them made. Link to comment
Ryan110484 Posted March 11, 2009 Author Share Posted March 11, 2009 I have built transistor based linear drivers, and switched capacitor buck drivers (STCS!). All have been on protoboards for now. I have been looking at the Zetex driver, and it seems interesting. The 1.25v reference for the dimming control is a pain if you want analog control, but seems painless for digital. Look at Eagle Cadsoft for board design. Basic version is free, and there are lots of guides on the web to show you how to use it. If you can make the board single sided, you can etch your own if you don't want the cost of getting them made. I suppose there isn't a pcb out there that I can just mount this thing to? It doesn't look like etching your own PCB's would be too fun. Lots of chemicals and I would probably just screw it up. Is there anyone on here who would be willing to make one for me? The price to DIY them verses just buying buckpucks is about 170 so its saving a decent amount of change. Could the PCBs be done for less then that? I would assume so, but is it worth the effort? Link to comment
evilc66 Posted March 12, 2009 Share Posted March 12, 2009 They could. There are some pcb prototype shops on the internet (sourcing out of China) that can do the pcb for pretty cheap in small runs. You will have to do some research on how much it will cost you to build the entire thing yourself, versus the cost of the Buckpucks. Link to comment
Ryan110484 Posted March 12, 2009 Author Share Posted March 12, 2009 evil- do you know where I can get the library for the zetec LED driver components? or is there a way to make them myself in eagle? I've watched the tutorial videos on how to make a schematic and turn it into a board, but its kind of difficult to make it without the proper parts. Link to comment
evilc66 Posted March 12, 2009 Share Posted March 12, 2009 Sparkfun has a tutorial on how to make your own part files. Link to comment
Ryan110484 Posted March 12, 2009 Author Share Posted March 12, 2009 Sparkfun has a tutorial on how to make your own part files. sweet. thanks! Link to comment
Ryan110484 Posted April 21, 2009 Author Share Posted April 21, 2009 I have ordered my LED's and plan on ordering everything else in the next few days. Now I just need to decide on meanwell or buckpucks. Link to comment
Ryan110484 Posted April 25, 2009 Author Share Posted April 25, 2009 So I am about 90% sure that I am going to get the buckpucks. The price difference between 7 Meanwell power supplies and 14 buckpucks (including PS) is only about 30$. Since the bucks are so compact I am gonna spend the extra money for space saving, unless someone has some input as to why I shouldn't. For dimming them is it really that simple as just a 5Kohm pot? seems too simple. As for wiring them up to a microprocessor can someone point me in the direction as to who would have a lot of info/step by step on how to do this? Link to comment
evilc66 Posted April 25, 2009 Share Posted April 25, 2009 A 5k pot really is that simple. Hookup to a micro is really easy. The datasheet says just connect it direct to the output pin. A 100K resistor would be a good idea potentially to reduce any current spikes. Link to comment
Ryan110484 Posted April 25, 2009 Author Share Posted April 25, 2009 If you don't mind me asking evil, why is it that you have switched to the meanwells over the buckpucks? Everyway that I have looked at it the buckpucks are easier to work with (it seems). I have not looked into prices for smaller arrays but for the larger arrays they aren't much different. Sometehing that your seeing that i'm not? Link to comment
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