# Needing help verifying that my circuit will work, before ordering.

#### -Ty-

Joined Feb 5, 2017
83
Hi everyone!

I'm putting together a Bi-colour LED light for photography. I need it to be virtually flicker-free, so I'm using a 25 kHz PWM dimmer, running off a 12V DC power supply. What I'm hoping to get some help on, is making sure that the products I'm planning on buying are... good? I just want to make sure that this circuit should work, based on what I have in my cart, before i put the order through.

THESE - are the LED strips. Each panel will have a full 5m of cold white, and a full 5m of warm white LEDs. Given that each has a listed power draw of 74W at 12V, I'm expecting a current of 6.2A per strip. This comes to 148W for the whole panel. To allow for the "Chinese Crap Tax" in terms of quality, I'm rounding that up to 200W for THE POWER SUPPLY.

The power supply will output in parallel to two 25 khz PWM DIMMERS, with one dimmer controlling the warm white, and another dimmer controlling the cold white.

As far as I can tell, my components should be good to function with each other, and should be capable of handling the load... But i'd still really appreciate some confirmation.

For summary:

LEDs: HERE
Power Supply: HERE
PWM Dimmers: HERE

One other thing I'm getting caught up on is the power supply.. there are a few different ones available at lower prices, but I don't know if i can trust them.

HERE is an alternative, for 28 bucks instead of 57.

I know that getting you guys to check my shopping carts for me seems quite lazy but, I've had very bad (and costly) experiences the few times I've tried doing something like this, so I'm quite weary...

Thank you all for your time and help.

#### spinnaker

Joined Oct 29, 2009
7,837
Doubtful anyone is going to be clicking on all of those links and then piecing this all together for you. Certainly no one is going to evaluate how good any of the components are And no one is going to be able to tell you to spend $57 rather than$28.

If you want a better chance that someone is going to help then you need to list all of the chosen components with their specifications and include a schematic of now you propose to connect things up.

#### jpanhalt

Joined Jan 18, 2008
8,329

Easy decision. Spend $28 instead of throwing$57 down a dark hole.

#### Hymie

Joined Mar 30, 2018
721
Looking at the 3 component part specifications (PSU/dimmer unit/LED strips), I would expect such a proposed set-up to function as expected.

The LED strips are rated at up to 60W per 5M length, so you might get away with a lower power PSU – at maximum output, your PSU will be supplying 120W to the LEDs, plus the power losses in the PWM units.

My main concern would be that the PWM unit is designed for motor control – but I would expect it to work when presented with the LED load.

#### -Ty-

Joined Feb 5, 2017
83
If you want a better chance that someone is going to help then you need to list all of the chosen components with their specifications and include a schematic of now you propose to connect things up.
Ask and you shall receive. The only reason I didn't include a circuit diagram from the start is because the circuit is too simple.. its essentially little more than a 6th grade "connect battery to lightbulb" circuit.

Unfortunately, no schematics of any of these components are available (or at least, I can't find them) -- they're all just generic chinese brandless items. No primary manufacturer, i dont know where to look to find a schematic.

#### -Ty-

Joined Feb 5, 2017
83
View attachment 164854

Easy decision. Spend $28 instead of throwing$57 down a dark hole.
Im just wondering, what makes you dismiss the 57\$ manufacturer as being a "dark hole"? Are you saying that both products are likely to be crap, so i might as well go with the cheaper one, or are you saying that there wont be any difference in quality between the two, or..?

Looking at the 3 component part specifications (PSU/dimmer unit/LED strips), I would expect such a proposed set-up to function as expected.

The LED strips are rated at up to 60W per 5M length, so you might get away with a lower power PSU – at maximum output, your PSU will be supplying 120W to the LEDs, plus the power losses in the PWM units.

My main concern would be that the PWM unit is designed for motor control – but I would expect it to work when presented with the LED load.
Yeah, unfortunately, I couldn't find any pre-built LED-focused dimmers on the market, and I definitely don't have the electrical knowledge to build one myself. All of the products available get marketed as being motor controllers, but some claim "Motor controller / led dimmer" in their title, but I know that amounts to peanuts.

That being said, I'm not wanting this circuit to live up to NASA standards - I know the circuit is less than optimal for LEDs. I just need it to work for a good five or ten years of infrequent usage. Do you think i could get away with that with these products?

As for the PSU, I want that extra headroom because i find that crappy nameless Chinese products almost never live up to the rated specs.