Achieved: Dimming to 0% black box chinese lighting Mars Aqua

EllaEresTu · 12/02/2017, 10:45 AM

Hi.
I've been able to dim all the way down to off a black box lighting with its original power supply, but i'm not sure of how to replicate it, so I ask you for help.

You can see a longer explanation in the video and see how I got to where I am now, making my light controller.

I read all the post I could find about dimming these light fixtures with no luck, so any help will be appreciated.

Thank you

EllaEresTu · 12/11/2017, 11:32 AM

I finally did it!
Sounds crazy, but short circuiting the power supply output did the trick as I suspected (LOL!)

I'll post a video and a demonstration when I'm done with my controller.

Do it under your own responsibility
Thank you.

mcgyvr · 12/11/2017, 11:47 AM

Yep.. Basically all the current is going through the short and the voltage will be below the Vf of the LEDs (zero) and as such they will not light at all

EllaEresTu · 12/12/2017, 11:24 AM

Quote:

Originally Posted by mcgyvr

Yep.. Basically all the current is going through the short and the voltage will be below the Vf of the LEDs (zero) and as such they will not light at all

Nope. I'm talking about a brief shot circuit with leds disconnected that makes something in the power supply that enables 0% dimming. It's a 1 time operation.

You'll understand clearly if I ever finish this

der_wille_zur_macht · 12/12/2017, 01:07 PM

It sounds like the PS had some sort of minimum voltage cutoff, and when your shorted it, you killed that part of the circuit.

Even though it's "working" as you want with full dimming, it would make me nervous to run like that, since that minimum voltage protection was probably there for a reason. Depending on the topology of the LED driver, it may need that protection to operate reliably or safely (ie not overheat).

If you've got the skills to set up dimming with an arduino then you probably have the skills to swap in dimmable drivers, right?

JUNBUG361 · 12/12/2017, 11:10 PM

Interesting, can’t wait for the video

mcgyvr · 12/13/2017, 05:53 AM

Its drop dead simple to just use a relay to open the output circuit to turn off the LEDS completely.. and I too would caution against attempting to benefit from the internal shutdown circuits unless that function is supported by the manufacturer of the driver IC as a proper enable/disable function..
Its usually for catastrophic failure/safety protection and not intended for continual operation like that..

Just because it works doesn't mean its right..

der_wille_zur_macht · 12/13/2017, 06:45 AM

I'd be nervous about using a relay or anything else to break the output circuit while the driver was hot, unless I knew the specifics of the chip running the driver. Many chips will basically go wide open if there's an open circuit on the output side. Then when you reconnect, the LEDs are essentially being WAY overdriven until the circuit stabilizes, which will be brief but can still be long enough to eventually start popping LEDs. I can speak to this from experience. Plus, anything put in the circuit on the output side means the driver is seeing that thing as part of the load it's trying to regulate. When the circuit is closed and stable that's not a problem, but something like a relay can be noisy as it's opening and closing, and you never know what that noise is going to do.

Breaking the imput side is probably safer.

12/02/2017, 10:45 AM	#1
EllaEresTu Registered Member Join Date: Sep 2013 Location: Madrid - Spain - Europe Posts: 4	Achieved: Dimming to 0% black box chinese lighting Mars Aqua Hi. I've been able to dim all the way down to off a black box lighting with its original power supply, but i'm not sure of how to replicate it, so I ask you for help. You can see a longer explanation in the video and see how I got to where I am now, making my light controller. I read all the post I could find about dimming these light fixtures with no luck, so any help will be appreciated. Thank you __________________ Please, excuse my possible bad English and expressions. It's not my first language :) Current Tank Info: 300l display+100 sump. all hand made by me

12/11/2017, 11:32 AM	#2
EllaEresTu Registered Member Join Date: Sep 2013 Location: Madrid - Spain - Europe Posts: 4	I finally did it! Sounds crazy, but short circuiting the power supply output did the trick as I suspected (LOL!) I'll post a video and a demonstration when I'm done with my controller. Do it under your own responsibility Thank you. __________________ Please, excuse my possible bad English and expressions. It's not my first language :) Current Tank Info: 300l display+100 sump. all hand made by me

12/11/2017, 11:47 AM	#3
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Yep.. Basically all the current is going through the short and the voltage will be below the Vf of the LEDs (zero) and as such they will not light at all __________________ Who me?

12/12/2017, 01:07 PM	#5
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	It sounds like the PS had some sort of minimum voltage cutoff, and when your shorted it, you killed that part of the circuit. Even though it's "working" as you want with full dimming, it would make me nervous to run like that, since that minimum voltage protection was probably there for a reason. Depending on the topology of the LED driver, it may need that protection to operate reliably or safely (ie not overheat). If you've got the skills to set up dimming with an arduino then you probably have the skills to swap in dimmable drivers, right? __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

12/13/2017, 05:53 AM	#7
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Its drop dead simple to just use a relay to open the output circuit to turn off the LEDS completely.. and I too would caution against attempting to benefit from the internal shutdown circuits unless that function is supported by the manufacturer of the driver IC as a proper enable/disable function.. Its usually for catastrophic failure/safety protection and not intended for continual operation like that.. Just because it works doesn't mean its right.. __________________ Who me?

12/12/2017, 11:10 PM	#6
JUNBUG361 Registered Member Join Date: Feb 2013 Location: Antioch,CALIFORNIA Posts: 1,091	Interesting, can’t wait for the video

12/13/2017, 06:45 AM	#8
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	I'd be nervous about using a relay or anything else to break the output circuit while the driver was hot, unless I knew the specifics of the chip running the driver. Many chips will basically go wide open if there's an open circuit on the output side. Then when you reconnect, the LEDs are essentially being WAY overdriven until the circuit stabilizes, which will be brief but can still be long enough to eventually start popping LEDs. I can speak to this from experience. Plus, anything put in the circuit on the output side means the driver is seeing that thing as part of the load it's trying to regulate. When the circuit is closed and stable that's not a problem, but something like a relay can be noisy as it's opening and closing, and you never know what that noise is going to do. Breaking the imput side is probably safer. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)