rrasco
Active member
Yes.
DIY LED driver for reef lighting
- Thread starter der_wille_zur_macht
- Start date
Yes.
SUMMERS
Premium Member
Thanks Slobdan. This helps me as well.
Krakonosh
New member
Hi all and happy New Year.
I'm building almost twenty of the TeraHz's drivers, got the boards and components to do the first ten. About half will be on Arduino based controller and the other half on Apex.
Now, I need to find a way to interface the 0-10V from Apex into these drivers.
The Apex max output is 20mA and the LM3409 v4 driver takes about that. So that doesn't leave much for an external voltage divider with 10k pot. I need to drive at least 3 to 4 boards per Apex output.
My question to TeraHz or others is: Can I change the voltage divider at the LM3409 to be able to drive it with 0-10V input, or do I need to build an op-amp circuit ?
I guess with the op-amp I could drive more drivers, but I have no idea how to build one.
Any help would be appreciated.
Thanks.
I'm building almost twenty of the TeraHz's drivers, got the boards and components to do the first ten. About half will be on Arduino based controller and the other half on Apex.
Now, I need to find a way to interface the 0-10V from Apex into these drivers.
The Apex max output is 20mA and the LM3409 v4 driver takes about that. So that doesn't leave much for an external voltage divider with 10k pot. I need to drive at least 3 to 4 boards per Apex output.
My question to TeraHz or others is: Can I change the voltage divider at the LM3409 to be able to drive it with 0-10V input, or do I need to build an op-amp circuit ?
I guess with the op-amp I could drive more drivers, but I have no idea how to build one.
Any help would be appreciated.
Thanks.
Power supplies
Power supplies
Just getting back to the project. Thanks Slobodan your reply does help. It appears the first step is to come up with a PSU at a reasonable cost. I checked
out octopart.com (thanks pandimus) and the selection is overwhelming, kind of like the proverbial haystack. If someone has a specific PSU
they could recommend my corals would be happy again. My T5's are well past replacement date. Any suggestions would be appreciated. Thanks
Clif
Power supplies
Just getting back to the project. Thanks Slobodan your reply does help. It appears the first step is to come up with a PSU at a reasonable cost. I checked
out octopart.com (thanks pandimus) and the selection is overwhelming, kind of like the proverbial haystack. If someone has a specific PSU
they could recommend my corals would be happy again. My T5's are well past replacement date. Any suggestions would be appreciated. Thanks
Clif
TheFishMan65
New member
Since we are now discussing (at least) 2 different drivers. I would like to remind folks that the CAT needs a 24 volt driver.
I for one was getting confused here
I for one was getting confused here
confused
confused
Fish,
If your confused think about those of us that have a limited background in electronics. The assembly of the driver doesn't seem all that difficult, its getting everything integrated as a cost effective unit that gives me pause. As I understand it if you go with a Meanwell HLG driver it has the PSU in it already. The question is what is the cost savings? Everything comes down to money especially when your retired. Having said that I still would like to go the DIY driver route. Thanks,
Clif
confused
Fish,
If your confused think about those of us that have a limited background in electronics. The assembly of the driver doesn't seem all that difficult, its getting everything integrated as a cost effective unit that gives me pause. As I understand it if you go with a Meanwell HLG driver it has the PSU in it already. The question is what is the cost savings? Everything comes down to money especially when your retired. Having said that I still would like to go the DIY driver route. Thanks,
Clif
TheFishMan65
New member
When I started there was not the HLG and paralleling was frowned on. So for 48 LEDs I would have needed 4 ELN at $35 each or $140. My board (8 drivers) cost me $35 with parts (it would have been more, but I sold the spare boards for cost). It is not hard to find a 24 volt supply for under $100. I actually did the ebay special and got one for $40 whcih can supply over 8 amps (I think it is 11 or 13). The board is about the same as the HLG which will do about 4 amps worth of strings at 42 volts (say 48 LEDs). The HLGs run $110 I think. So if you can find a good inexpensive power supply DIY is cheaper IMHO. I think there are some 6.5 amps 24 volts in the $15-20 range.
Has anyone had any heating issues with their 3409s? I'm looking to set up 3 in an enclosure including a typhon to control it but I was curious to know if it needed a fan. I'm doing an 8g led pendant with three 3ups (two rb one nw per star run separately) and three turquoise for the added spectrum. Of course, each driver has different amperage (1a nw, 2a rb to drive parallel sets of three and 500 ma for the turq) and I'm planning on running it off of a 12v 5a supply. I am planning on using the lower resistance transistor to keep the heat down also. anyone have any input? If it doesn't have any geat issues, ill be able to fit everything in a box about the size of four driver pcbs in a square (not including the power supply).
der_wille_zur_macht
Team RC
Heat is so specific to the operating parameters and component choice that it's hard to say. I would not put them in an enclosed box with no ventilation at all, for sure. If they are well designed for minimal heat for your operating parameters, there's good passive cooling, and your packaging in that enclosure is well designed, I would suspect you'd be OK, but I wouldn't design yourself into a dead end without testing the concept.
kcress
New member
terahz
1x10^12 Hz
LM3409HV i2c
LM3409HV i2c
Ok guys, here is my last revision of the LM3409HV based driver. Quite a few changes in this one.
As I hinted a while back, my ultimate goal was to have this driver on the i2c (or similar) bus. And that's what I've done. I've added a 12bit i2c DAC on the board that allows for nice 4000+ step analog control. I've also changed the PFET to a TO-220 package and added a space for a monster heatsink
About I2C dac:
There were really only a couple of options for a DAC choice. MCP4725 and MCP4726. The two are basically the same DAC, but one has external addressing, while the other has external reference voltage. In general, either chip will work with the board, however with the MCP4725 you need to set the last address bit via the smd jumper.
Addressing:
Both chips use 1100 for first 4 bits + 3 additional configurable pins.
On the MCP4725, you have 4 options when you order 110000X, 110001X 110010X and 110011X where X is set to either 0 or 1 via the external smd jumper.
The MCP4726 doesn't have external configurable pin, so there are 8 available options from Microchip. However I was able to find only the first 4.
What does all this mean?
It means that with current availability, you can put 8 drivers with MCP4725 or 4 drivers with MCP4726 on a single i2c bus.
Now if you don't need more than 4 drivers per bus, the MCP4726 can give you one extra feature: external maximum override via potentiometer. Basically you can use the 3 pin jumper to wire a potentiometer and you're effectively using that potentiometer to set the maximum control voltage that will go to the driver.
Programming:
Since this is now i2c and not just a PWM, you can't just digitalWrite(LEDPIN, 255); Howerver it is not very hard to talk to the DAC. It takes 4 bytes:
1 byte - address
2 byte - commands
3 and 4 byte - registers of the 12 bits (last 4 bits are ignored)
I'll probably have a library for it sometime in the near future.
As always, open source and all files can be found here:
http://joro.geodar.com/code/LM3409 v0.6/
Enjoy
LM3409HV i2c
Ok guys, here is my last revision of the LM3409HV based driver. Quite a few changes in this one.
As I hinted a while back, my ultimate goal was to have this driver on the i2c (or similar) bus. And that's what I've done. I've added a 12bit i2c DAC on the board that allows for nice 4000+ step analog control. I've also changed the PFET to a TO-220 package and added a space for a monster heatsink
About I2C dac:
There were really only a couple of options for a DAC choice. MCP4725 and MCP4726. The two are basically the same DAC, but one has external addressing, while the other has external reference voltage. In general, either chip will work with the board, however with the MCP4725 you need to set the last address bit via the smd jumper.
Addressing:
Both chips use 1100 for first 4 bits + 3 additional configurable pins.
On the MCP4725, you have 4 options when you order 110000X, 110001X 110010X and 110011X where X is set to either 0 or 1 via the external smd jumper.
The MCP4726 doesn't have external configurable pin, so there are 8 available options from Microchip. However I was able to find only the first 4.
What does all this mean?
It means that with current availability, you can put 8 drivers with MCP4725 or 4 drivers with MCP4726 on a single i2c bus.
Now if you don't need more than 4 drivers per bus, the MCP4726 can give you one extra feature: external maximum override via potentiometer. Basically you can use the 3 pin jumper to wire a potentiometer and you're effectively using that potentiometer to set the maximum control voltage that will go to the driver.
Programming:
Since this is now i2c and not just a PWM, you can't just digitalWrite(LEDPIN, 255);
Howerver it is not very hard to talk to the DAC. It takes 4 bytes:1 byte - address
2 byte - commands
3 and 4 byte - registers of the 12 bits (last 4 bits are ignored)
I'll probably have a library for it sometime in the near future.
As always, open source and all files can be found here:
http://joro.geodar.com/code/LM3409 v0.6/
Enjoy
Note taken from kcress and DWZM. I'm planning on giving everything a test run before i build the enclosure.
Oh, and if anyone wants some LM3409 boards, I will have about 12 available in a week or two... I ordered from Itead studio a set of 8 red originally, which i thought were cancelled due to a paypal screwup. I went and ordered another ten to make up for the problem and they printed both sets. Just PM me if you are interested.
der_wille_zur_macht
Team RC
Awesome work terahz. This is really cool to see the flexibility and power we're building for now compared to where this thread started more than 2 years ago.
