An LED is a light-emitting diode. Lighting an LED is considered the "Hello world" of a circuit design, and it can be as simple as putting a series resistor or can get more complicated, involving PWM and multiplexing.

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Advice to connect Smd led to battery [on hold]

I need to connect four 5w 9-12VDC Smd led to 12v 40ah battery in my office. Please advise me with circuit.
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34 views

controlling multiple RGB LED's [on hold]

I'm currently in 1st year for electronics and I want to do a project. Basically I'm going to control about 150 LED's and make them each have different colors. Then I will put white glass over the ...
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1answer
44 views

How long will my battery last and how to calculate it? [duplicate]

I have a 12V 18Ah battery I wish to run through a boost converter at 40v and 2.5A to power a 100w led. Could someone figure out how long my battery would power my led and show the ...
0
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4answers
92 views

10 Watt LED and LED Driver related question

I got a 10watt LED from Ebay but never thought that the driver and heat sinks are must-haves for this little master. When googled, I found several circuits of LED driver. But none of them are ...
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63 views

How can I make joule thief battery last longer

I assambled a simple joule thief circuit powered by 1 AA battery to light up just 1 LED. I read that with that kind of circuit you may drain down the battery to light up an LED for about a week. But ...
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1answer
33 views

Can you power a LED with a lower tension but the right current [duplicate]

Can you power a 50w LED that by the datasheet needs 30v and 1.5A with less than 30v but 1.5Amps?
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37 views

VIsible Light COmmunication using Arduino for masters thesis [on hold]

I am currently doing my Masters in electrical engineering. As part of my Master's thesis I want to conduct some research/project in Visible Light Communication using arduino. I have a time frame of ...
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1answer
59 views

Voltages to keep my circuit running at 200mA with NMOSFETS

Im trying to build a circuit to send information using IR led, using pulse signals my leds (TSAL6400) operates at 1.35V, and their maximum pulse current is rated 200mA After struggling a bit with ...
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2answers
86 views

Charlieplexing: a LED producing light very slightly, although it shoudln't, based on its forward voltage

I have a display of a few LEDs, using charlieplexing: The display devices don't have any other parts, and don't have any space to place any parts either. The resistors are on the wires A, B and C ...
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54 views

What resistor would be needed before two LEDs in series?

I was wanting to use the lowest amount of amps in my project because it contains around 60 LEDs. http://www.rapidonline.com/pdf/55-2484.pdf : The technical description It has a max current of ...
0
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4answers
128 views

How to increase the current in this circuit?

Im trying to build a circuit to send information using IR led, using pulse signals (Im trying to mimic a home appliance remote control). My leds (datasheet) operate at 1.3V, and their maximum pulse ...
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1answer
65 views

How calculate inductor discharge time through LED?

UPDATE Overnight I realized I'd been sleeping as I read part of the textbook I've been using or at least didn't quite fully grasp the purpose of inductor volt-second balance. I added the results of ...
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1answer
34 views

Portable power supply for over 300 ws2812 LEDs (similar to youtube video)

I have an idea fro a project which requires a few hundred ws2812 LEDs to be powered using relatively small battery which can be carried. I was wondering how you could power over 300 ws2812 LEDs ...
0
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1answer
89 views

Can I ignore resistor for IR LED?

I have two IR diodes and I want to connect them to my Raspberry Pi. From Pi I have 3.3V voltage. Diodes are TSAL 6200 . Can I connect them to PNP and my PI without resistor safely with this wiring?
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2answers
65 views

Multiple resistors to reach needed value?

Im converting an old floodlight to a cree led to run off my solar setup for a yard light I need a 27ohm resistor for a 3.5v 350ma single led to run off 12.5v, but don't have any that value, what ...
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1answer
35 views

Will a 110-220v to 12v converter work with a DC 12v 3w LED bulb? [closed]

I'm planning to create some wall lights using these LED bulbs. Would I be able to just use any 110-220v to 12v converter to power this at home? I live in the US (120v). I was thinking of using this ...
2
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2answers
80 views

Mixed forward voltage LEDs in series with constant current driver

I've been looking for answers for a few weeks, so now I'll actually voice my question! My plan is to power 109 LEDs in series off of one constant current driver. The goal is to create supplemental ...
0
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1answer
37 views

Driving a 5V IR led with a 5V charger?

I'm trying to build a remote control with IR led. I'm experiencing low range with my 1.5V, If=50mA IR leds, so I looked for and found a 5V, If=100mA IR leds. twice the current, hence probably better ...
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2answers
123 views

PWM ~100mA LED's [closed]

If someone knows of a prototyping solution for driving several LED's at >75mA I'd be grateful. I've taken 8 LED's out of an existing product. They appear to expect 70mA to 100mA for max brightness. ...
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2answers
74 views

Power LED from 100v outlet [closed]

Here is my project.I want to buy this 100x led : ...
2
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1answer
166 views

RX/TX LED for MAX232

I want to use two LEDs to show send and receive on my max232 RS232 to TTL (5v) converter. I have seen this method as the most conventional way to power an LED for max232: I tested it and the LED ...
9
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1answer
283 views

Dangers of IR LED

I would like to build a DIY laser tag system. The website milestag recommends a Vishay Tsal-6100 as IR-LED. Here is a datasheet: http://www.mouser.com/ds/2/427/tsal6100-279822.pdf Since I want to ...
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2answers
323 views

Does changing the Voltage and the Current passing through an LED affect the result in the same way?

More directly : passing electricity that is 0.5 times the amperage of the one required will make the LED half bright, right? Is it the same with halving its voltage requirement? Or will it not turn on ...
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1answer
86 views

Using optocoupler with MOSFET for dimming a LED

I have a blue LED which I want to dim using an Arduino, an optocoupler and an N-MOSFET. For achieving this I assembled the circuit on a breadboard as shown in the pictures, using a YwRobot breadboard ...
0
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2answers
72 views

Replace some LEDs with Diodes [closed]

I have a COTS solar battery charger that has a number of different LEDs identifying the battery level, if its charging, etc. Its going to live in the shed, so 99% of the time no one will see its ...
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1answer
54 views

Why is wiring some LEDs in series better than wiring them all in parallel?

I noticed a lot of guides for making an LED array or matrix prefer to wire their LEDs in series first and then wire strips of leds in series in parallel. What is the benefit of this Vs wiring them all ...
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1answer
56 views

Calculating resistance to make BJT transistor act as a switch

Let's say you're given a circuit diagram as follows: I want to find R1 and R2 so that forward voltage drop across the LED is 2V with an overdrive factor of at least 2. Current of 25mA from a ...
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2answers
33 views

Led matrix display atmega32

I need help with an LED matrix I am building for my son, running from an atmega 32 and a BC818 transistor. I have the schematic from http://dhassel.de/projects/cool/led-matrix-display/ In the ...
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1answer
52 views

Car DRL Led wiring beginners question

I bought this relay (http://www.ebay.co.uk/itm/400972235163) and this LED DRL lights (http://www.ebay.co.uk/itm/400757922989). The questions are: Can I attach 2 led lights to this relay (as it ...
3
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4answers
429 views

LED's flash with music

I am wanting to put have a few LED's flash with the intensity of my music. I don't need a color organ, but just want the LED's to flash in sync with the music. I am amplifying the signal with a LM368 ...
3
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1answer
117 views

Is it possible that my UV LED is emitting white light? If so, how would I filter out the white light?

I recently purchased a 365 nm UV LED, and set up the proper circuit. When I turn the power on, the LED lights up very dimly. Is this white light (that's the color I saw) being emitted from the LED? ...
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2answers
83 views

How to place “Power On” indicator lights?

I'm working on a replacement board for an old system. I have two terminal blocks. Terminal Block 1 (left) is the input from the power supply to the board. This is the primary power supply to the ...
0
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1answer
46 views

Average lifespan of COM-12986 Addressable LEDs?

I am working on a project where I need to ensure that LEDs will work for at least 5 years (powered 24 hours/day). I need LEDs to be addressable like COM-12986. Would this be a good choice (the LEDs ...
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1answer
44 views

How do you calculate the resistor value for a bicolor led

R4 and R5 have equal values. For both LEDs the forward voltage is 2V and the forward current is 30mA. I know how to calculate the correct resistor for a single LED. However in this case I am using a ...
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2answers
49 views

Calculated resistance of an LED

I am working on some circuit lab homework this week and am a bit stumped by something I just can't seem to find anywhere in my Circuit Analysis I book. The lab has me construct the following circuit ...
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2answers
69 views

What does the waveform for a Digital Addressable LED Strip look like?

I want to use this Digital LED Strip but with my own controller (i.e. NOT a raspberry Pi). The link has sample code but I want to be able to understand clearly in terms of hardware waveforms what ...
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2answers
84 views

Output data from computer to light up LEDs

I'm a complete newbie at this, but the idea is to have a circuit board with, say, 10 LEDs, connected via USB to a computer running Linux. This will periodically (e.g. every second) send data to the ...
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0answers
30 views

how to simulate temperature PN-junction of LED in Solidworks

I am simulating one heat-sink for one LED Lamp, So i am using Solidworks for this simulating similar to this : and it works but i want to simulate temperature PN-junction of LED So have i must ...
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3answers
71 views

Wiring two leds

I have two questions. If I have one led 2.2v@20mA and other one 2.2v@15mA, can I use them in series connection? Or do I have to use parallel wiring? And if I have 2.2v@20mA and 3.2v@20mA leds, can ...
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3answers
106 views

On/Off Circuit for my USB LED [closed]

Its my very first question here and I am very new to circuits. I have an LED with USB connect port that turns On when connected to my PC. I want to make a circuit and turn it On/Off using some ...
3
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1answer
141 views

Is there any reasonable cause for a LED driver to yield more voltage than it is labeled with?

I'm trying to make a light using an existing COB LED module of unknown health, and a new 300 mA constant current LED driver. I hooked up the LED to the LED driver and got 38V DC on the output instead ...
0
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1answer
42 views

Constant Current IC Driving a String of ICs

I have been having difficulty wrapping my head around the ideas of constant current and constant voltage. Basically I have assembled this circuit with an arduino. Now, imagine that I wanted to ...
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1answer
210 views

Why does this zener diode fix the voltage to the LEDs?

I am just getting started working with small electronics. I have soldered together a few kits and recently converted a car stereo into a home stereo. With all of this soldering, I found this ...
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2answers
47 views

Multiple led drivers for a single LED

I have a couple of moving heads like this They have a QCL (Quad color led chip) Theres a total of 10w. Most of the time I don't use the colors, I just use the white quadrant, which I presume is 10w. ...
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0answers
72 views

Noise being created on Sensor after connecting Power Source to LEDs

simulate this circuit – Schematic created using CircuitLab So I posted this issue on the arduino forums and haven't had much luck getting any visuals on it. I have an arduino and shield ...
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1answer
64 views

ATMEGA32 LED BLINKER Assembly code problem

I tried the following code for a simple led blinking problem on ATMega32. ...
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2answers
60 views

Led charge indicator for small supercapacitor (1F x 5.5v)

I have been playing around with a supercapacitor, 1F rated 5.5V. I charge it mostly through USB, which usually takes a couple of minutes to reach a good amount of energy. I have been thinking about a ...
0
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2answers
137 views

Resistors for transistor led circuit

Im new to electronics and have problems with calculating the resistors needed for driving an IR LED with an transistor. My VDD is 3.3V, the LED needs 1.3V and I want to drive it close to 20mA, so I ...
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2answers
92 views

What are the real properties of an ordinary LED?

I would like to simulate a typical LED in MATLAB. However, I need the following info: Internal resistance (in Ohms) Internal capacity (in Farads) Self-Inductance ( in Henries ) All of the values ...
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1answer
71 views

Multiple TLC5940s on PCB “dropping out” when many outputs turned on

I've designed a PCB to connect 12 TLC5940s to an 8x8x8 RGB LED cube through 3 64-pin headers, which I will include screenshots of below. I have a separate board for controlling the anodes for ...