Just something to note!
This board is was designed for the LDD-H driver and not the LDD-L!
I've had a read through the spec sheet of the driver noted the logic levels for the PWM:
L: <0.8V,
H:2.5>6V Or open.
This means, it the voltage on the PWM pin goes above 2.5V the LED will come on, and if reduced to below 0.8V it will go off (fundimentals of PWM). This means it will not work on a 0-10V analog output (applied voltage), but could be minipulated to work on a 0-10V PWM output (unfiltered) and provided it falls with in the 100-1KHz range!
As for the 0% dimming and the resistor, I'm not sure and perhaps I need to do a bit of reading, as it didn't make sense to me with a quick glance. There would not be a need for the resistor (pull down) if you are driving the LDD-H from a micro controller as the micro controller will sink the PWM to ground anyway. It will not reduce the voltage either, as it does not form a part of a voltage dividing network. And the fact that if the PWM pin is left open it "defaults" high the driver must have an internal pull up resistor biasing it high.
I just need to have a read on this and give it some more thought as to why this was done.
@TheGrove do you perhaps have some direct links to posts where this has been addressed.
Also, by soldering a resistor on over those exposed SMD pads, it would do nothing, as that runs in series with the other "open circuit" holes (perhaps for a jumper?), Im not sure.
Hi @lIghty, Resistor is a pulldown resister and activated by a jumper.
Sorry I though it was rather clear that this is for the LDD-H and not the LDD-L as it was mentioned a number of times.
My plan is to use this with an arduino which has been tried and tested. If you are planning to use it in another way unfortunately you will need to do the research and feel free to post and findings here.
link to the full specs page of the LDD-H driver it lists the specs of all the different variates as well as the PWM info.
http://www.mantech.co.za/Datasheets/Products/LDD-H.pdf
The Pulldown Resistor (correct use)
Meanwell LDD driver: for those who want to dim to 0 using Arduino - Page 43 - Reef Central Online Community
Post #1061
The pull down resistors are used to prevent the LDD's from going "full throttle" in cases where they're being controlled, or dimmed down to prevent Coral bleaching. If the controller fails for any reason and stops sending a PWM signal to the LDD's. The LDD's will turn "Off"
In simple terms, lets say you build a 300W unit and you use a controller to dim the LED's to 150W to prevent bleaching of corals, if yuo do not have a resistor in place and your controller failes the Drivers switch to full power 300W. But now if you have a resistor in place with a jumper on this board then that wont happen, if the controller fails it will turn the LED's off. So think of it as a safety feature. So please ignore my previous post around using a resistor on the PWM to drop voltage!!!
Ok so everything should now be clear
1. you require 5V PWM not 10v analog (there are converters available)
Post #1474 Meanwell LDD driver: for those who want to dim to 0 using Arduino - Page 59 - Reef Central Online Community
Gerber files and design of the converter.
2. Pull down resistor is for if the controller fails it will turn the led's off instead of running them full throttle (ensure jumper is on)
3. With 6 x LDD-1000H it can take up to 300W of LED's depending on your config.
4. ONLY for the LDD-H Range of drivers
5. Proven and tested with Arduino.
6. For easy installation of the LDD-H you can use something like this ISM24 - SOCK DIL 0.6 TULIP RND WID P24 just make sure the driver fits the socket before buying. (a bit better than the previous one I posted. and used widely on Reef Central)
Any questions?
And thanks to everyone that has shown interest and given their ideas, much appreciated and hopefully we can perfect this and come up with an affordable/simple/quality DIY LED solution.
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