Please help with dimmer for my ATS led lights

[Levinson]

I need some help/advice on how I can dim my led lights.
I've bought an ATS from Aliexpress. From my experience using my current DIY ATS, I'm pretty sure I need far less light intensity and I would really like a dimmer for the led.
Before buying, I just assumed it would be some 12 or 24v LED lights and thought I'd use a cheap simple dimmer switch (the rotating kind) like the one I'm using for my current ATS but I don't think the lights are 12 or 24v.
I don't know much about electronics (so I could be wrong, in which case, please correct me) but judging by the power adapter (24-46v, 300mA), the number of leds (12), and the power of lights (12w), I'm guessing the leds on the pcb are in series and around 3v, 300mA each? I haven't taken the light-box apart because it's sealed. I don't even know what the 24-46v on the adapter means. Does it mean the voltage is somewhere between 24 and 46?
I don't think the 12-24v dimmer switch would work in this case. From what I understand, led dimmers work by adjusting DC current (ampere) or by turning on and off very fast (PWM dimmers). Would a PWM controller (like this) work for this light? Is there any other way to control this light? I've heard not all leds are dimmable and what works for one may not work for another but if it's not too costly or risky, I'm willing to try something out.

 

[monkeyCmonkeyDo]

The power supply looks like a constant voltage yes

 

[monkeyCmonkeyDo]

Non dimable I'm thinking
D

 

[Levinson]

Non dimable I'm thinking
D

Do you think a PWM controller could work?

 

[Levinson]

If I can't find a better way, I'm thinking of giving a PWM motor speed controller a go. I know it may not work but I'm willing to take the risk wasting money on the controller. Unless it won't work for sure.
The ones I could find that is rated over 46v are rated 0 to 20A or higher. I need 0.3A so it should be aright right?
Is there anything I should be aware of?

 

[oreo54]

The power supply is a constant current driver ..
You need a different driver .

Easiest enough to replace it w/ a meanwell Ldd and a constant voltage power supply.
Can dim it with a modified $3 manual dimmer...

Or find a meanwell ac/dc driver w/ pot dimming.
24-46v output
300mA

Or other brands..

LED Driver Constant Current - AC Electronics AC15CD350AT2S | 1000Bulbs.com

Adjust the AC Electronics AC15CD350AT2S LED driver to the current you need from 250, 300, or 350mA. Find the constant current driver you need at 1000Bulbs.com!

www.1000bulbs.com

You dim by applying 0-10v dc on the dim wires.

As to the ldd
Not knowing the exact diode count and specs...
48v power supply 15watts or greater .,
Ldd-300hw.
Modified dimmer ( need to add one wire)
and a cheap voltage regulator to drop the 48 to 12- 24 volts to power the dimmer.
Sounds a lot but relatively easy and cheap.

Ps and meanwell driver..$17 plus shipping

LEDSupply - For All Your LED Project Needs!

Voltage regulator and dimmer on flea bay for about $5 each

Substitute manual dimmer for TC-420

Tap off the mosfet gate to get 5 v pwm.

 

[oreo54]

"IF" this is what it was reported to be it is slightly easier to use..
The green connector in the upper right hand corner "should" be a 5V PWM tap.
No guarantee. Others did report it as such but I've never used it.
Still need the other parts though.
Oh and 12 diodes generally will have at least 36V V(f) so 48v ps is not an option but a requirement.

PWM Dimmer for LED Lighting with 12-Button IR Wireless Remote 12-24VDC 6A | LEDwholesalers

Only possible catch is if the frequency is a mismatch between the ldd and 5v pwm output.
Currently uncommon with led dimmers, common if using fan/motor speed control dimmers.

 

[Levinson]

The power supply is a constant current driver ..
You need a different driver .

Easiest enough to replace it w/ a meanwell Ldd and a constant voltage power supply.
Can dim it with a modified $3 manual dimmer...

Or find a meanwell ac/dc driver w/ pot dimming.
24-46v output
300mA

Or other brands..

LED Driver Constant Current - AC Electronics AC15CD350AT2S | 1000Bulbs.com

Adjust the AC Electronics AC15CD350AT2S LED driver to the current you need from 250, 300, or 350mA. Find the constant current driver you need at 1000Bulbs.com!

www.1000bulbs.com

You dim by applying 0-10v dc on the dim wires.

As to the ldd
Not knowing the exact diode count and specs...
48v power supply 15watts or greater .,
Ldd-300hw.
Modified dimmer ( need to add one wire)
and a cheap voltage regulator to drop the 48 to 12- 24 volts to power the dimmer.
Sounds a lot but relatively easy and cheap.

Ps and meanwell driver..$17 plus shipping

LEDSupply - For All Your LED Project Needs!

Voltage regulator and dimmer on flea bay for about $5 each

Substitute manual dimmer for TC-420

Tap off the mosfet gate to get 5 v pwm.

Thank you very much for the detailed response.
Goodness, it seems far more complex than I had imagined it to be. I guess it isn't as simple as just constant voltage & adjusting the current.
I have yet to get my head around it but I'm trying my best to understand it by searching online and reading your post over and over.

Please excuse me if they are dumb but before reading your post, some of the ideas I had thought of include;
- getting one of these (or similar) Bluetooth led drivers to replace the power supply
- take the light box apart and rewiring the LEDs in groups of 4 or something (get a new pcb? I don't know how) and run them on a new 12v adapter and hook up a 12v dimmer switch.

 

[oreo54]

Thank you very much for the detailed response.
Goodness, it seems far more complex than I had imagined it to be. I guess it isn't as simple as just constant voltage & adjusting the current.
I have yet to get my head around it but I'm trying my best to understand it by searching online and reading your post over and over.

Please excuse me if they are dumb but before reading your post, some of the ideas I had thought of include;
- getting one of these (or similar) Bluetooth led drivers to replace the power supply
- take the light box apart and rewiring the LEDs in groups of 4 or something (get a new pcb? I don't know how) and run them on a new 12v adapter and hook up a 12v dimmer switch.

Sadly the drivers you linked to do not have enough "ooompf".. i.e voltage for the
12 diodes in series.
Messing with the board itself is possible but a lot riskier. You'd need to cut the right traces and add contact points.
Then to make it constant voltage you'd need to add terminating resistors to each of the new strings.

What I posted is actually easier than you think.
Only thing one needs to do, besides buy parts, is solder one wire and then just wire it all together

The buck converter can output any voltage from about 9-24V.
you can use a "wallwart" to power the dimmer instead of the buck converter but you would need to join the 2 power supply grounds together.. NOT the + side.

MOST, if not all strip dimmers are built the same way and can be used the same way..
I've converted 3 different units to work as the above..
TC-420, Manual dimmer, and a bluetooth unit..



That was dimming both a 3W cyan led and a 12v strip light. LDD controlled the output to the 3w diode, strip light used the "output" on the dimmer. Of course the power supply was 12V.

OH btw wiring the LDD backwards will burn it out..
Red black to power supply, blue yellow to diodes..

 

[Levinson]

Sadly the drivers you linked to do not have enough "ooompf".. i.e voltage for the
12 diodes in series.
Messing with the board itself is possible but a lot riskier. You'd need to cut the right traces and add contact points.
Then to make it constant voltage you'd need to add terminating resistors to each of the new strings.

What I posted is actually easier than you think.
Only thing one needs to do, besides buy parts, is solder one wire and then just wire it all together

The buck converter can output any voltage from about 9-24V.
you can use a "wallwart" to power the dimmer instead of the buck converter but you would need to join the 2 power supply grounds together.. NOT the + side.

MOST, if not all strip dimmers are built the same way and can be used the same way..
I've converted 3 different units to work as the above..
TC-420, Manual dimmer, and a bluetooth unit..



That was dimming both a 3W cyan led and a 12v strip light. LDD controlled the output to the 3w diode, strip light used the "output" on the dimmer. Of course the power supply was 12V.

OH btw wiring the LDD backwards will burn it out..
Red black to power supply, blue yellow to diodes..

Thank you.
I'm based in Korea so I will have to look first but I think I can find most stuff here (or from Aliexpress) but the LDD, I'm not so sure about yet. I hope they have them. Shipping stuff from the US to here is crazy expensive nowadays so that's not really an option.

Some questions if I may,
- I thought the LEDs used for my unit operate at 3 ~ 3.3v each, if so, then shouldn't 40v be enough to drive 12 of them in series (3.3v * 12 = 39.6v)?
- Does the "48v, 30Watts or better" written on DC Supply in the diagram correct when the light is 12W?

 

[oreo54]

Thank you.
I'm based in Korea so I will have to look first but I think I can find most stuff here (or from Aliexpress) but the LDD, I'm not so sure about yet. I hope they have them. Shipping stuff from the US to here is crazy expensive nowadays so that's not really an option.

Some questions if I may,
- I thought the LEDs used for my unit operate at 3 ~ 3.3v each, if so, then shouldn't 40v be enough to drive 12 of them in series (3.3v * 12 = 39.6v)?
- Does the "48v, 30Watts or better" written on DC Supply in the diagram correct when the light is 12W?

LED will "pull" the amps as needed(based on the voltage applied to it) so wattage is just something to look at as "minimum requirement"..
At say 3.3V and 300mA wattage is 11.8Watts.. MINIMUM.
3.3 x 12 x .3 = 11.8 Watts
The included driver is maxing out its "potential" and is not a good match in "my" mind .
It's a little trickier than that but as a "rule of thumb" that driver is the smallest possible, not the best possible, at a 12W rating.

Least "common useage" driver should have been designed for 11.8W + 10% safety factor 12.98 Watts.
A 48V driver designed for "30W" has plenty of room to not stress the circuitry.

Adding DC/DC step down drivers usually involves some "overhead" so a
power supply outputting 36 Volts can only supply like 36-3V. So you only have 33V.
3.3 x 12 + 3 volts = 42.6V
Unless you actually test the voltage of the light at that current (easy enough) you do not know what it's ACTUAL voltage needs are.
IF the current driver is actually doing what it says it's doing, just measure the voltage across the diode string while it is running at the light head, past the driver. Use caution but you are only dealing with 30-ish volts and 300mA of current.
STILL proceed with caution.
IF the current driver is working, checking the current in series (say the + side) should be 300mA =/- that 5%.

Simplest definition: A buck ldd driver regulates voltage by dropping it to maintain a set current.

Think of it as a voltage regulator with an added purpose of maintaining a set current.


Thus the 48V power supply.Common sizes come into play

If your string is 3.3v x 12= 33 + 3 = 36 volts. If the string varies a bit (diodes are NOT consistent across lots especially for cheaper diodes) you can have any combination of voltage sums from say 36 to 44.4.

Technically as the diode heats you can even require less voltage needed to maintain 300mA of current across the string but now it's getting a bit more complicated.
Best to design as a "worst case" scenario. In this case a "worst case" guess is 3.7 volts x 12.
44.4V + 3 = 47.4 for the power supply.

I actually can't imagine you not being able to get the parts in Korea..


Sorry about any redundancies.. just my style..

 

[Levinson]

Thank you yet again. That was much educational and helpful.
I've still looking for some of the items needed from the list (and how to get them cheaper).

While researching, I found another way that would work.
Using the Triac dimmer switch with a LED driver that supports it. Dimmer on the AC side.
Although I'd much prefer to have a dimmer switch much smaller than the one in the picture below. Not sure if the other small cheapo AC dimmer switch would also work.

Also, I've read that the red LED diodes have lower forward voltage compared to the white ones, typically in the ranges of 2~2.5v. My light box LED diodes consist of 9 reds and 3 whites. I'm just making guesses here not knowing if it sounds dumb or not but could it be the 40v bluetooth driver just might have enough "ooompf" to operate? ((2.5v*9)+ (3.3v*3) = 32.4v minimum) Since I don't plan on using the lights at their full potential but at much lower power?
Sorry if I sound too clingy about the idea of using the 40v bluetooth driver.

 

[oreo54]

Lol, I had been assuming normal " reef" type lighting or plain white leds ( ats as in algea turf scrubber went over my head ) did not factor in red ( or related) low V( f) diodes.
Devil's in the details eh.
So yes a wattage "downgrade" for the 12 in series.
Secondly Bluetooth strip dimmers "should" work the same as the manual one with the one modification.

As to AC dimming sort of a seperate animal altogether.
One thing is it seems that there is a potential for dimmers not matching the drivers well.
Things like leading edge or trailing edge models.
Again not my cup of tea.

Theoretically works fine with the right driver/dimmer.




I'm not familiar w/ any that use Bluetooth to dim on the ac side.
You are sort of into the "smart plug " for dimming incandescent lights territory.
Can't really help you there.


And the driver you posted earlier still can' t be used. Current is too high even if voltage now matches and you can use triac dimming.
Btw now at 10 watts (32.4 x 0.300) the driver makes more sense.

As a simple " grow-light" at 10 watts I'm not seeing the need for anything but a simple on/ off smart plug via bluetooth. That should be easy to find.