3v to 5v logic converter and power requirements

@madmisha Hi, I have 3 of those LED strips in my RV I mounted in the pantry, under the sink and around the kitchen island. The LEDS use 12V, that is what I have in abundance. I then use a LM2596 to drop the voltage to between 7 and 8 to apply to the ESP32 or in one case an Arduino ProMicro. They both have internal regulators to get the voltage down the 3.3 they use.

NO you can't send the 5V to both ends. Also, I see your LEDS are 5V, mine are 12V. For your LED power use a medium sized USB wall wart. Your LEDS need 15W according to your link.

I don't know why you think you need 150W, that 10x too big.

2 of my 3 strips are controlled by mag switches through a mosfet module, the 3rd is radar controlled through a mosfet module. In my case the module gets wired to 12V in and out and the gate is triggered by an esp32 pin, pretty simple. There is a dropping resistor on the home made mosfet module to get the 12V down to gate voltage but the 2 store bough don't need it, it's internal I guess.

Posted by: @madmisha

Could I send the same 5V to both sides safely?

Yes, to clarify, you can feed both ends of the strip from the SAME 5V power source, but you can't use different sources at each end. 

@zander 

I went with the 150W power supply because the manufacturer, as well as reviews, recommended 100W for one roll. I am extending it beyond one roll. I also ordered a very pixel dense strip because I plan on doing some color chases with it. I ordered the Black PCB IP65 16.4ft 300LEDs (x2 , will be cut down). Looking at it now, they are really power hungry. Their math checks out, assuming the power rating per LED is accurate.

It looks like they rounded up/left a small cushion, that's what I would have done anyways. I should also take into account that there will be a voltage drop over that 24'.

This is the part that confuses me.

The added voltage. It makes it sound like you can power it from both sides. I went with this brand because of what I wanted to do and fairly good reviews, but the broken English makes it a little confusing. They should arrive today so I can do some testing. There could be a diode there and only allows the voltage to extend to the next strip, but it would make more sense to do that on the connector and not even hook it to the flex PCB.

I forgot to mention it, but I also got a few short connectors/wire so that I can do whatever I needed to do.

Posted by: @will

Posted by: @madmisha

Could I send the same 5V to both sides safely?

Yes, to clarify, you can feed both ends of the strip from the SAME 5V power source, but you can't use different sources at each end. 

Ok, thank you. That was what it sounded like but I was unsure. I would never power it with 2 different power sources. And now that I think of it, I will check to be sure that the output terminals are in fact parallel before doing so. I doubt it wouldn't be.

@madmisha 

Good to see you back, it's been a long time.

@madmisha All I know is my strip is 300 LEDS that uses 15W powered with 12V. I do see where your instructions actually call for more voltage to be added every 5M. Never heard of such a thing. Good luck.

@will 

Yeah, good to be back. I've been working so much that I haven't had any time to play around with electronics. Now I feel really rusty and doubt everything. I swear, everything is easier at 120 to 480 volts. That's where I'm comfortable.

I'm just surprised that not much has changed in the small electronics maker space since I stepped out. There is a new Raspberry Pi micro but my old go to (ESP32) is still preferable. Maybe I'll see the need for it later.

@zander 

Are they WS2812 with 5050rgb chips? I have a few of the regular separate RGBW channel ones and they do run much lower power. For this project, I really wanted to do pixel mapping, since I do that at work. This might also be converted to DMX addressing/control later. I am also taking a gamble on not having a white or amber channel. I might not get the colors I truly want. I will have to play around with it to find out. But I do know that I need all 3 LEDs lit to get a white and so I am planning on using full power requirements.

@zander 

To clarify, the WS2812B LEDs are RGB LEDS and each colour runs up to 20 ma.

So the total current required is draw/colour times number of colours times number of LEDs in the strip. This means 20 ma x 3 colours x 300 LEDS/5m strip = 18 A maximum power per strip.

Running from 5V means that 5 x 18 = 90 Watts are required for each 5m strip. That's how much it takes to light all of them up as white light at full power. He'll probably wind up using them far below the 60 ma because he won't need (or want) the full brightness.

Posted by: @will

He'll probably wind up using them far below the 60 ma because he won't need (or want) the full brightness.

Nah, stick a Binford sticker on it and blast it!

Actually...your probably right, I don't need a blind kitten.

@madmisha I have both but so far only connected the white leds, the addressable coloured are in the input queue. I figured there would be a difference, but from 15 to 150 seemed extreme. 

@will Ok, that makes some sense. The most recent strip I hooked up came with a dimmer, I have it barely turned on, them suckers are bright. The colored LEDS are for Xmas lights around the windows so they will be running at pretty much the lowest brightness. They will be driven with some sort of music trigger, not sure yet if it will be a speaker and mic arrangement or just voltage from the audio waveform.

Posted by: @madmisha

Actually...your probably right, I don't need a blind kitten.

It's a cat, it doesn't need much light to start with 🙂

@will If I think of it tomorrow, I will try getting my clamp on ammeter on one of the DC leads to get a amp reading. Since I have the dimmer cranked almost off I don't expect much. BTW Will this morning I saw the radar at work, I had eyes on when the lights turned on. I was 90 degrees to the sensor through at least an inch of wood and some misc stuff in a storage bin. VERY sensitive.