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Topic: Help with LED lamp project (Read 513 times) previous topic - next topic

racegig

Hello everyone,
I want to add 6 regular RGB Led to a circuit that was powering an RGBW led strip using 3 mosfet (PMW¨) with an Arduino Nano.
I couldn't find any info on this LED strip:
https://globe-electric.com/en/product/globe-electric-wi-fi-5m-16-4-ft-smart-multicolor-changing-rgb-dimmable-led-strip-light-no-hub-required-voice-activated-50053-2/

In the Fritzing drawing below is the circuit that should work (but I'm not shure being a complete Newbie). I left out the white led on the strip (couldn't find the RGBW led drawing in Fritzing) but just suppose it's there :)

Questions:
I connected the 6 Led to the same wires of the Led strip. Is this OK (I want these led to be the same color as the strip).

Are the 220 ohms resistors OK for this circuit?

Is the 100uF Capacitor OK and at the right place in this circuit?

I have a switching 12V (3 amps) power supply to power 2 arduino nano + 15 feet of led strip + 6 regular RGB led. Is that enough ?

I hope all this make sense to you.

Thanks in advance...



vaj4088


racegig

I did insert an image from my Google photos (link) but I guess it didn't work...

larryd

#3
Apr 01, 2020, 06:24 am Last Edit: Apr 01, 2020, 06:42 am by larryd
OP circuit:




If you are using LEDs that do not have current limiting, a series resistor at a minimum, you will damage components.
FYI, (@ 12V you will need ~470 Ω series resistors.)



Use logic level MOSFETs  IRL540 for example.




No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

racegig

Wow! thanks for the quick response.

So if I understand, you suggest to:

replace the three IRF540Z with IRL540

and replace the three 220 Ohms resistors with three 470 Ohms...

The circuit you show is using 5V, so I'm a little confused. I'm using 12v to power the Nano and the Led's.

This is for an electric guitar lamp project. It consist of one Arduino Nano for controlling the colors and the light at the top of the guitar neck (lamp shade) using the 4 guitar pots. The other Nano (this one) will control the light inside the hollow body guitar. Two additional push button will be used to change modes.

My test circuit is working fine right now and nothing seems to be a problem (I let it lit for a couple of hours). But I just decided to replace the little dots on the guitar fretboard with flat RGB led's that will fallow the inside of body led strip mode or color.

I thought that I could just plug them on the same wires used by the strip. But was not certain if I needed to beef up the resistors, Mosfet and cap.

I hope all this make sense English is not my mother tongue.

Below is a photo montage of the final lamp.

racegig

Forgot to tell that when I tested my circuit, I was using only ONE FOOT of strip.

Maybe that's why it did blow up...

P.S. Not the actual guitar on photo. Mine has 4 pots instead of two.

TomGeorge

#6
Apr 01, 2020, 08:15 am Last Edit: Apr 01, 2020, 08:46 am by TomGeorge
Hi,

Quote
I want to add 6 regular RGB Led to a circuit that was powering an RGBW led strip using 3 mosfet (PMW¨) with an Arduino Nano.
Was the original RGBW controlled by the 3MOSFET and NANO?
OR
You are making a new circuit using 3MOSFET and Nano?

If the latter how was the original RGWB strip controlled.

Quote
Maybe that's why it did blow up...
What blow up?? ?? ? :o

Are the RGB LEDs 12V already?

Can you post a picture of the RGWB strip terminations and the RGB LED.
It looks and sounds like you need to use current limit resistors on the RGB LEADS, to limit the LED current and not blow things up.
Have you got a DMM?

Thanks.. Tom.. :)  

Everything runs on smoke, let the smoke out, it stops running....

larryd

#7
Apr 01, 2020, 08:42 am Last Edit: Apr 01, 2020, 08:42 am by larryd
replace the three IRF540Z with IRL540
Yes

and replace the three 220 Ohms resistors with three 470 Ohms...
No the MOSFET 220R is okay.
I am talking about a series resistor for each LED colour.


The circuit you show is using 5V, so I'm a little confused. I'm using 12v to power the Nano and the Led's.
If if these are simple RGB LEDs, you need ~470 ohms in series with each R, B, G LED element.
The image offered just shows that each LED needs a resistor (this is for reference only).







No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

TomGeorge

#8
Apr 01, 2020, 08:48 am Last Edit: Apr 01, 2020, 08:48 am by TomGeorge
Hi,
You will need to drive your RGB LEDs like this if they are a single four legged LEDs.


Tom.. :)
Everything runs on smoke, let the smoke out, it stops running....

racegig

Here are the pictures requested.

I did not receive my Flat Led's yet (they should arrive yesterday), but I included a photo from seller.
I just figured out (slowly but surely) that the +12V inscribed on the led strip means that it is 12V ready and that the resistors are built in. But the Led's are not 12V so I have to protect them all with 470 Ohms resistors.

Description of the flat led from seller: (notice how the different color have different voltage)

1. Forward Voltage: R: 1.8-2.0 G: 3.2-3.4 B: 3.2-3.4
2. IV: R: 5000-6000 G: 6000-7000 B: 2500-3000
3. XY/WLD: R: 630-640 G: 515-525 B: 465-475
4. Light Color: RGB
Condition: 100% new
Size: 5mm
Emitted Color: Red / Green / Blue
Pins sequence: RED/Common Anode (positive terminal)/Green/Blue
Please test to add current limiting resistor, it will be very easy to burn out the LED resistance of a few hundred to 1000ohm
R: wavelength 630-640nm Brightness 1000-1200mcd Voltage 1.8-2.0V
G: wavelength 515-525nm Brightness 3000-5000mcd Voltage 3.2-3.4V
B: wavelength 465-475nm Brightness 2000-3000mcd Voltage 3.2-3.4V
Package
20pcs Tri-Color 5mm flat top 4 pin RGB Red Green Blue Common Anode LED Lamp Light

The strip came from an already available kit that included a one push button controller, 16.4 feet of strip and a power supply ( Output 12V , 2000mA). You can control this strip with your phone over wifi (but I only use the strip without the included controller).

The power supply I want to use is 3 amps, so I guess will be enough for 2 Nanos + 6 led's + 14 feet strip.

My circuit is based on one I found on the web that was using mosfet and external 12V (not from arduino) since the current needed is more that the Nano can stand.

What about that 100 uf Capacitor ? Is it OK to put it there in my circuit and is it strong enough ?

P.S. See your LED array that I modified, to validate that I'm a slow learner...

racegig


racegig

The interior RGBW strip will be controlled by Nano as follow:

On start:  White light only
pushButton == 0 White only 
pushButton == 1 Rainbow color mix fade mode
pushButton == 2 Red only
pushButton == 3 Green only
pushButton == 4 Blue only
pushButton == 5 whatever color I desire
pushButton == 6 All off

The other Nano has the pots connected to it and I can manualy mix color or dim (This is the strip that is exterior, in the lamp shade).

TomGeorge

Hi,
OPs pics.


Yes those connections will be correct.
DMM is a Digital Multimeter, if you are going to continue with electronics it is advisable that you get one.
For this sort of work an elcheepo DMM that will read your low voltages and currents.

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

racegig

Great!! Thanks Tom.

I really appreciate you guys spending your precious time helping me with that project.

I do have a digital multimeter, but I'm not sure what I would check in this case :)

P.S. Next project will be an automatic nutriment and PH monitoring and adjusting in my hydroponic system. So you will probably hear from me again...:)

racegig

Many thanks also to you Larryd :)

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