39 votes

Is DC 5V and 2A dangerous to me?

200mA is lethal (actually much much less is lethal) and can kill, but only it if gets inside you. For it to get into you, it needs enough voltage behind it to push into you. If there is enough voltage ...
DKNguyen's user avatar
  • 56.7k
26 votes

Calculate battery life

I would like to know how to calculate battery life when using LED strip. The LED strip is powered by 8 AA batteries. LED Current Draw = 260 mA. Right. The batteries will be discharged at 260 mA. This ...
Transistor's user avatar
  • 176k
14 votes
Accepted

Powering 20 m LED strips

You don't need two power supplies. One is enough. Just connect the positive wire to one side of the strip and the negative to the other. Then you will have equal voltage at each LED group and this ...
Todor Simeonov's user avatar
14 votes

Is DC 5V and 2A dangerous to me?

To make it easy: 1- Car battery 12V (hundreds of Amps) will not kill you. Laptop charger 20V 7A will not kill you. Therefore, the 5V 2A will not kill you also. Most of power sources you will see ...
Ashraf Almubarak's user avatar
13 votes
Accepted

5V vs 12V addressable LED efficiency

This is more interesting than it first appears. WS2815 appears to have been made in more than one revision but the latest design uses a clever constant current series trick. The lower half is a ...
Richard Aplin's user avatar
12 votes

Is DC 5V and 2A dangerous to me?

The power source you are looking into is a voltage source (like 99% of the power sources you interact with in your daily life). This means that 2A is the maximum it is designed to supply, but it will ...
lvella's user avatar
  • 257
11 votes

What voltage is a 3-LED light from a LED-TV?

The 94V marking you see on the PCB is not a supply voltage rating. 94V-0 is a UL marking indicating the flammability rating of the PCB material. As others have said, you ideally need a constant-...
brhans's user avatar
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11 votes
Accepted

Why would I need a capacitor in front of a LED strip?

The wire between your power supply isn't just a wire – it has a resistance and an inductivity. People tend to use thin wires, much too thin, and then wonder why their stuff fails in mysterious ways. ...
Janka's user avatar
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10 votes
Accepted

What is the RGB value of Edison Light Bulbs?

I used Firefox Web Developer Eyedropper to grab the RGB from a photo of an Edison Light Bulb. #FACA08 (250,202,8) A lighter pixel This is very close to the color when a 2700K 97 CRI LED was ...
Misunderstood's user avatar
10 votes
Accepted

Is it good to wire WS2813 LED strip DI and BI together?

No, not connecting the BIN doesn't eliminate the backup functionality. As for what to do with it, the official datasheet at http://www.world-semi.com/DownLoadFile/117 doesn't say, so I won't ...
Jostikas's user avatar
  • 298
10 votes
Accepted

Why do the television manufacturers (Samsung, Sony, LG, so on) exceed the voltage capacity on LED strips (backlight) on TVs?

Isn't 133V the open-circuit voltage? When LEDs are working, voltage should be lower. LEDs are driven by constant current sources, it's far better than using voltage regulation, because LEDs have ...
Grabul's user avatar
  • 3,472
10 votes
Accepted

Decoupling capacitor selection criteria for this multi-IC system

Each Neopixel is basically an IC. So each IC should have a 100nF cap right at the supply pins. Unless told otherwise. A single large capacitor far away from ICs is not helpful for many reasons.
Justme's user avatar
  • 148k
10 votes

Decoupling capacitor selection criteria for this multi-IC system

Read the note just below the one you refer to on the webpage you linked:
DKNguyen's user avatar
  • 56.7k
9 votes
Accepted

3.3v regulator problem when sharing power source with LED strip

The IRU1015-33 has absolute maximum input voltage of 7 V. You are operating the IC way outside its design parameters. Anything can happen, and 12V on your communication module is a real possibility. ...
Ale..chenski's user avatar
  • 40.6k
9 votes

DIY LED lamp is less powerful than expected

Your connecting wires are too thin, you are dropping voltage in your leads. You need to select the right size of wire and potentially use a star connection to drive the strings. If your strip is ...
Jack Creasey's user avatar
  • 21.7k
9 votes
Accepted

Edge-lit LED panel best materials?

What are the best materials to use for this? These panels are built in the same way as LCD monitors with LED backlight. Well, monitors have a LCD in front of the backlight panel, but you get the idea....
bobflux's user avatar
  • 77.4k
9 votes
Accepted

Building a simple USB notification light

The cable is just that... a cable. The ring light doesn't have a USB interface. The Arduino's role was to interface between USB and the light. You need to keep either some Arduino, or another ...
Kuba hasn't forgotten Monica's user avatar
9 votes
Accepted

RGB digital to analog converter

WS2812 protocol is based on different high/low times to encode bits, it's non standard, and pretty fast (~1-2µs/bit). You could use a microcontroller but it will have to run code in a tight loop to ...
bobflux's user avatar
  • 77.4k
8 votes
Accepted

How do I get the PIR sensor to output more than 3.3v?

The PIR sensor output is a signal. It is not intended to drive LEDs directly. Fortunately we have such things as transistors that can switch LEDs on and off in response to a signal like what the PIR ...
Olin Lathrop's user avatar
8 votes

Is DC 5V and 2A dangerous to me?

Short answer No, Long answer, The confusion here comes from a few common misconceptions/misunderstandings. First being, "Current kills, not voltage" or similar. Yes, it is the amount of current ...
H. Daun's user avatar
  • 181
8 votes
Accepted

How to combat voltage drop on a 5v addressable led strip

how do I inject voltage into the strip without making the design look like overhead power lines? Run secondary 5V and GND wires that you connect to the far end of the strip. You can route them ...
Kevin Reid's user avatar
  • 7,524
8 votes

Matching number of LEDs to power supply

According to the datasheet, the LED's Vf is 3.05V @ 1500mA, which is close enough to the 1400mA constant current provided by your power supply. The power supply's maximum output voltage is 69V. 69V / ...
Unimportant's user avatar
  • 4,598
7 votes

Will a LED strip be less bright when I drive my mosfets with 3.3V instead of 5V?

They probably will, in my opinion, but there is no guaranteed with such a MOSFET. The key number is the guarantee of Rds(on) at the lowest gate voltage shown in the "Specifications" section. Vgs(th) ...
Spehro Pefhany's user avatar
7 votes

Using L7805CV instead of TIP120?

I have a L7805CV transistor No, you don't have one of those, as there is no such thing. You have a 7805 voltage regulator (which is not a transistor). and its looks same to TIP120 That is just ...
SamGibson's user avatar
  • 17.9k
7 votes

Calculating base resistor value

First you have to determine what the maximum collector current is that the transistor needs to support when on. Divide this collector current by the gain of the transistor to get the minimum required ...
Olin Lathrop's user avatar
7 votes

Why is 12V the standard for LED strips?

12V might be the "quasi" standard because of the 12V car batteries/electrics that were there years before the LED strips. Of course no one is driving a single 3V led with 12V and a resistor directly....
Stefan Wyss's user avatar
  • 7,430
7 votes
Accepted

Right way of wiring discrete LEDs to make a high power LED panel

There is a resistive component to the LED I-V curve, which is especially significant at higher currents. This helps in making the current distribution more even. The Vf of the LEDs will vary with ...
Spehro Pefhany's user avatar
7 votes

Decoupling capacitor selection criteria for this multi-IC system

Also of note: use a ground plane design, preferring component placement and trace routing on top side, with minimal jumps to the bottom side, which is filled with GND. (Using a few extra vias to ...
Tim Williams's user avatar
7 votes

What does "G D C +" or "G C D +" stand for on LED strip controllers?

I would assume that G D C + stands for Ground / Data / Clock / +V. bigclive did a nice tear down on this if you are interested https://www.youtube.com/watch?v=jOo5lf4tVT4
DrG's user avatar
  • 665

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