Dimming the nondimmable

[Reverend Turtle]

I have a basic knowledge of wiring, etc., but am having an issue finding an answer to a possible problem. I am rebuilding a couple of older led black boxes, and finding replacement power supplies has been a bit frustrating.
I found 4 on Ebay, and ordered them, but the seller could only find 3 of them to ship. So the hunt is on for a fourth. I see many inexpensive drivers that provide the correct power, but they are not dimmable according to the suppliers.
Is there a way to dim the output power using such a power supply? I have an apex jr that I had wanted to program to control my lights. Don't know if that is pertinent information or not.

I've always used T5's in the past, and this is my first foray into LED's.

Thank you kindly.

 

[jsker]

Lets see if we can get you some help. Me, I would burn down the house when comes to correct lighting wiring ;Hilarious

 

[oreo54]

I have a basic knowledge of wiring, etc., but am having an issue finding an answer to a possible problem. I am rebuilding a couple of older led black boxes, and finding replacement power supplies has been a bit frustrating.
I found 4 on Ebay, and ordered them, but the seller could only find 3 of them to ship. So the hunt is on for a fourth. I see many inexpensive drivers that provide the correct power, but they are not dimmable according to the suppliers.
Is there a way to dim the output power using such a power supply? I have an apex jr that I had wanted to program to control my lights. Don't know if that is pertinent information or not.

I've always used T5's in the past, and this is my first foray into LED's.

Thank you kindly.

dimming non-dimming drivers is "possible' but def. not recommended..
Here is my idea of why..

Constant current drivers regulate the output voltage to match a part. current set point.
In the case of a sort of no load (light off) conditions some just go to max voltage out.
When one closes the circuit then the driver needs to adjust voltage so as to meet current setpoint.

Point is at some point in time your leds are seeing the full voltage potential of the driver.
Depending on the driver and how fast it responds determines how long your LED's see excessive voltage.

When I started building lights and using AC/DC Meanwells one of the KEY recommendations was to not connect a string to a "hot" driver or you'd burn out the LED's.
In a practical sense though I've done it successfully w/ out burnouts but no telling if the LED lifespan was compromised.
Those drivers were not the 100V DC out types though either

As to dimming.. Adding a logic level power MOSFET to the output will allow one to turn the output on/off and duty cycle will determine the dimming..

So answer is yes and no.

Edit: No need for a logic level NPN MOSFET if using Apex but would need to convert the 10V analog DC to PWM.
I suppose there is some other circuitry that would work but out of my pay grade (knows enough to be dangerous).

There ae a few Meanwells that can substitute for the orig drivers w/ caveats.
Mostly you can get th right voltage range but usually means higher or lower current set point.
so no "exact" match.
Believe Inventronics has some even closer but not easy to find.
SBReefs carries "originals" for their bb type lights but only for customers..
You know they should just retail those things..

Strings are 28 and 27 long so you need drivers that output about 104V DC assuming 3.7V(f) per diode on the longest string.
Min voltage of the driver matters also..
APC-35-350 100v max dc @350mA possibly works but 2 things we short on voltage so the string may never reach 350mA, not harmful but wasteful. Should work fine for the 27 diode side
Like I said there are compromises.

Your orig drivers are probably around 550mA or so.

Actually these should work, others can correct me if necessary:
HLG-120H-C1050AB NOTE AB only!
74-148V
Dimmable and current and voltage adjustable.
Lowest current is 525mA

Of course at $50 each.. might as well buy a new bb.

HLG-120H-C1050A MEAN WELL USA Inc. | Power Supplies - External/Internal (Off-Board) | DigiKey

Order today, ships today. HLG-120H-C1050A – 1.05A 74 ~ 148V Constant Current LED Driver AC DC Converter Topology 1 Output from MEAN WELL USA Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

 

[Reverend Turtle]

Lets see if we can get you some help. Me, I would burn down the house when comes to correct lighting wiring ;Hilarious

Thank you.

 

[Reverend Turtle]

dimming non-dimming drivers is "possible' but def. not recommended..
Here is my idea of why..

Constant current drivers regulate the output voltage to match a part. current set point.
In the case of a sort of no load (light off) conditions some just go to max voltage out.
When one closes the circuit then the driver needs to adjust voltage so as to meet current setpoint.

Point is at some point in time your leds are seeing the full voltage potential of the driver.
Depending on the driver and how fast it responds determines how long your LED's see excessive voltage.

When I started building lights and using AC/DC Meanwells one of the KEY recommendations was to not connect a string to a "hot" driver or you'd burn out the LED's.
In a practical sense though I've done it successfully w/ out burnouts but no telling if the LED lifespan was compromised.
Those drivers were not the 100V DC out types though either

As to dimming.. Adding a logic level power MOSFET to the output will allow one to turn the output on/off and duty cycle will determine the dimming..

So answer is yes and no.

Edit: No need for a logic level NPN MOSFET if using Apex but would need to convert the 10V analog DC to PWM.
I suppose there is some other circuitry that would work but out of my pay grade (knows enough to be dangerous).

There ae a few Meanwells that can substitute for the orig drivers w/ caveats.
Mostly you can get th right voltage range but usually means higher or lower current set point.
so no "exact" match.
Believe Inventronics has some even closer but not easy to find.
SBReefs carries "originals" for their bb type lights but only for customers..
You know they should just retail those things..

Strings are 28 and 27 long so you need drivers that output about 104V DC assuming 3.7V(f) per diode on the longest string.
Min voltage of the driver matters also..
APC-35-350 100v max dc @350mA possibly works but 2 things we short on voltage so the string may never reach 350mA, not harmful but wasteful. Should work fine for the 27 diode side
Like I said there are compromises.

Your orig drivers are probably around 550mA or so.

Actually these should work, others can correct me if necessary:
HLG-120H-C1050AB NOTE AB only!
74-148V
Dimmable and current and voltage adjustable.
Lowest current is 525mA

Of course at $50 each.. might as well buy a new bb.

HLG-120H-C1050A MEAN WELL USA Inc. | Power Supplies - External/Internal (Off-Board) | DigiKey

Order today, ships today. HLG-120H-C1050A – 1.05A 74 ~ 148V Constant Current LED Driver AC DC Converter Topology 1 Output from MEAN WELL USA Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

Thank you for all the information. Yeah, I was trying to find a less expensive alternative. I bought the lights used, they are seven years old, some of the diodes are fried so while I was in there I thought I would replace as much as possible. Want to make them as reliable as possible with a better color spectrum.
Again, thank you,
Aaron