DIY LED driver for reef lighting

a buddy just put me on to a really cool search engine. octopart.com they search all the companys for electronics and give you the lowest part.

That's awesome, thanks.

On that note, does Future sell the CAT4101 chips in less than a 750 count? The part that says "Std Packaging Qty: 750" leads me to believe that the 1-9 pricing is for reels of 750.
 
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They actually just switched to quantity pricing for the CAT. It used to be $1.92 even for 50. I have made several batches of my board for group buys. I figured why not group buy the parts too.
 
2) Check Jameco. The last bag of three hundred I purchased was cheaper there.

Good thought, they're a place I hadn't checked yet.

They actually just switched to quantity pricing for the CAT.

Yeah, it looks like they're only selling whole reels of 750 now, which is really too bad. The sales rep they assigned me calls once a month or so, next time she calls I'll ask why they made the switch.
 
Hey guys,
I remember seeing excel spreadsheet that does calculation for values of required components for TeraHz LM3409HV design. Does anyone have link to it??
I'm not sure for what current 0.5ver of TeraHz design was made for but I'm looking to run some CREE XPGs at 1.0A
 
I have one question about PWM signal requiered for CAT4101. Is Arduino's 5V directly compatible with it or should I put something betwen?


a) Arduino > something > CAT4101
b) Arduino > CAT4101
 
I have one question about PWM signal requiered for CAT4101. Is Arduino's 5V directly compatible with it or should I put something betwen?


a) Arduino > something > CAT4101
b) Arduino > CAT4101

Arduino > CAT4101 is fine. Nothing else is needed.
 
Lm 3409 hv

Lm 3409 hv

Hi All,
I have been following this thread for some time and have decided to go the DIY route using Terahz' LM3409 V5,
thanks Terahz. I hope i'm not getting in over my head and if I am I hope there is a lifeguard within
shouting distance. I do have 48 XP-E RB, 24 XP-g CW, and the heat sinks ready to go. For openers I do have a couple of questions, how many of the LM3409 V5 will I need to drive 72 Cree's set up in parallel strings and what do I need for power supplies? Also a friend decided to build along with me so I guess this project could be called a perfect example of "the blind leading the blind".
Thanks, Clif
 
Hi Guys. I have been running the 3xCat4101 boards and all has been well. Just got all my parts and boards in for the LM3409HV chip. Couple of quick questions.

1. With this board having analog dimming, will I be able to use my Apex Jr for sunrise sunset now? I'll order the VDM if so and just run a Cat cable. I dont think the VDM could be used with the Cat4101 I have now but wasnt sure if it might work with the LM3409HV.

2. With the LM3409HV I see it was designed for 48v but I should be able to use my 24v PSU correct? It would just mean 6-7 XPE instead of the 14 Tehraz is using, no?

Thanks to all the contribuers in this thread.

Best Regards,

Larry
 
Hi Hawker1,

From documentation you can find this info:
VIN Range: 6V to 75V (LM3409HV/LM3409QHV)
So, your maximum voltage is 75V that you can put into LM3409HV. I wouldn't really push it to the maximum, not even sure if you can find power supply that will do this.
Main thing is to find forward voltage of a diode for example XPG CW has forward voltage of 3.2V if runs with 700mA current. Let's say that you want to use 75V powersupply then you have 75/3.2 = 23.4375 Then your maximum would be 23 LEDs per one LM3409HV chip. Again, I wouldn't push it to the maximum and you have to be careful of what Vout of power supply really is.
Your LEDs forward voltage (3.2 x 23leds) has to say as close as possible to your power supply so you avoid overheating LM3409HV chip.
The same way you have to calculate for XP-Es .
I hope this helps you in some way as I'm not sure if I explained this very well.
 
Hi Hawker1,

From documentation you can find this info:
VIN Range: 6V to 75V (LM3409HV/LM3409QHV)
So, your maximum voltage is 75V that you can put into LM3409HV. I wouldn't really push it to the maximum, not even sure if you can find power supply that will do this.
Main thing is to find forward voltage of a diode for example XPG CW has forward voltage of 3.2V if runs with 700mA current. Let's say that you want to use 75V powersupply then you have 75/3.2 = 23.4375 Then your maximum would be 23 LEDs per one LM3409HV chip. Again, I wouldn't push it to the maximum and you have to be careful of what Vout of power supply really is.
Your LEDs forward voltage (3.2 x 23leds) has to stay as close as possible to your power supply so you avoid overheating LM3409HV chip.
The same way you have to calculate for XP-Es .
I hope this helps you in some way..
 
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