Meanwell LDD driver: for those who want to dim to 0 using Arduino
- Thread starter pwreef
- Start date
oreo57
Well-known member
You're right - I don't like your answer! But that doesn't mean I completely disagree with it
See if I can get explicit confirmation from them...
Tim
Sounds good. Half the battle is framing the question correctly..
Usually analog dimming just convert analog level to PWM signal.
oreo57
Well-known member
That has been my assumption based on the driver circuitry..
People assume input "waveform" is equal to output waveform..
In the case of switching constant current drivers I don't think it applies..
Especially where the different types of dimming (analog/PWM) are on the same pin (circuit).
I could see a separate circuit that would change the r sense resistor value, cutting down the constant current value.
Output will still be "pulsed" but w/ a lower peak value..
I don't see the Meanwells being designed this way though..
I don't - i don't know enough about circuit design to assume anything like that! But i do assume that what is fairly clearly suggested (not implicitly stated) in a data sheet and then confirmed by the company to be true, is!
Which could be a false assumption for two reasons:
1. As you say, normally the output is PWM, and a single unit doing both would be unusual.
2. The first reply i got from meanwell (not posted that yet, but i will)...
Tim
RCD-24-1.00/PL/A-R has 2 inputs
One - for analog, it's just a resistor
Second - standard PWM
I've used them from a project: http://reefcentral.com/forums/showthread.php?t=2338224&page=2
They works exactly as described from datasheet, but there is a little problem with them: 8 channel cost $160
crn005
New member
Alright, it's a simple question but I want to make sure before I go wiring everything up. In regards to wiring up the circuit board, if you're looking at it from the top, there are ten terminals on the top of the board (it's a 5 LDD coralux). The left five (terminals 1-5) are for the PWM signals from the controller. The right five are labeled "G, G, G, V, V". The "G" represents the negative wire from the PS and the "V" represent the positive wire from the PS, correct? Why are there multiple terminals for each? What exactly goes into them?
crn005
New member
I got it wired up laid out on the floor in front of the tank. I plugged it in, and it worked! Then I accidentally pushed the LDD board into the PS, a few sounds were made, then my typhoon controller went blank. The damn thing won't turn on now. What can I do to fix this? I really don't want to have to buy another controller....I'm not happy right now. Dang it!!!
So in response to my earlier question to Meanwell, I got a very simple response:
Tim
I have removed his phone number and email as I did not ask for permission to put them on a forum
I have asked for clarification over the comment in the spec (which was posted as an image in his reply) about the output changing to PWM if the input is PWM but have still had no response to that
Tim
I have removed his phone number and email as I did not ask for permission to put them on a forum
oreo57
Well-known member
So in response to my earlier question to Meanwell, I got a very simple response:
I have asked for clarification over the comment in the spec (which was posted as an image in his reply) about the output changing to PWM if the input is PWM but have still had no response to that
Tim
I have removed his phone number and email as I did not ask for permission to put them on a forum
Hmm.. Pretty worthlesss response
(Theirs not yours)..........
Krazie4Acans
New member
Why couldn't they just call the graph an "Analog characteristic reference curve" and then state that output is PWM in both input methods?
I think it's time to build myself a scope and connect one of these new LDD's up to find out for myself. Krazie :jester:
oreo57
Well-known member
Yep got a bunch of Ldd-h's myself.. no L's..
oreo57
Well-known member
Why couldn't they just call the graph an "Analog characteristic reference curve" and then state that output is PWM in both input methods?
Much appreciated..
Krazie4Acans
New member
Ask and ye shall receive! I have confirmed that the LDDL's that support analog dimming input still output an PWM signal on the output. So while they do provide convenience in options for input, they are not changing what the LED's are seeing on the output. The only way to "truly" run lower current on the LDD's is to use a lower value output LDD. This is true for the Ls and the Hs.
Hope that helps someone out there. I only use the H's myself and already use PWM so this is for informational purposes only.
Krazie :jester:
oreo57
Well-known member
Thank you. it has been bugging me for quite some time..
so much for deceiving graphs.. and stupid no nothing engineers..
