Questions tagged [led-driver]

An LED driver is a self-contained power supply that controls the amount of current and voltage supplied to an LED light. An LED constant current driver monitors the loop current of each LED and automatically adjusts the generated DC voltage output to the minimum value needed to produce the highest forward voltage. As mains power is AC and Light Emitting Diodes run on DC, this current needs to be converted by a rectifier

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0-10V Digital Rheostat for LED Dimmer?

I have an LED light with a power supply that follows the ISO 60929 0-10V standard for dimming. The manufacturer says "the power supply is current sourcing, and is roughly 0.5mA." The following ...
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Why do LEDs require a constant current source and not a constant voltage source as power supplies?

Most electronic devices use constant voltage source as power supplies. Why do LEDs require constant current source?
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Dimmable AC LED controlled by Arduino

I am a beginner, and I have a school project that requires me to use Arduino or any other microcontroller to control an LED light. After some research, I found out that not all LEDs support dimming, ...
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Driving two leds with PAM2803

I'm planning to drive two white leds like these (datasheet) with PAM2803 driver (datasheet) and a single cell lipo battery. Before ordering a pcb, I'm testing on a breakout board. With a 0.13 Ohm ...
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LED bulb can not start properly (BP2832 based)

I bought several LED bulbs about 2 years ago, and now before turn LEDs steady on, some of them flash for some time. Frequency of flashing may differ from bulb to bulb. After some time flashing, they ...
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Help refining a current control loop circuit

As a follow up to this question. (Sorry if this linking other posts is wrong. I'm new to forums) Will this design for an XHP70.2 LED Driver with arduino control work to the params specified? TL;DR: ...
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516 views

Driving High-Power RGB LEDs

I would like to use a 30W RGB LED that is in common-anode configuration. The issue is the voltage ranges for the LEDs are different, 20-24V for red, and 30-36V for green and blue. Is it possible to ...
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The mysterious case of the random leakage current

Disclaimer: I already know the solution of this circuit debugging conundrum (and it is not trivial), and I'll post it after some time, so that other people could give their contribution to this ...
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MeanWell 3-in-1 dimming

I've got a constant current MeanWell LED driver that has 3-in-1 dimming (100k potentiometer, 0-10V signal or 10V PWM), and would like to control the dimming with a microcontroller. I found a few ...
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Is it OK to PWM a current source?

I want to control power RGB LEDs, for efficiency and safety they are better to be driven by a current source. I can use either linear or buck converters. I made a linear current source using ...
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Linear current driver with several BJTs in parallel

With the circuit setup shown below, if I have available a type of Q2 transistor with a certain maximum dissipated power and need that D1 withstands a large current that would lead Q2 in trouble, it is ...
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Optocoupler driving 300mA continously (or use darlington topology?)

Looking at driving two LED strings with a DC/DC constant current LED driver module. The constant current side can't be referenced to ground of the control circuit, so I need to have an isolated ...
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Dimensioning smoothing capacitor for China DIY LED lamp

My first question here so bare with me if I'm a bit "off" or so regarding the level of knowledge etc. My purpose is to try to learn things. So I started off by buying some LED lamp DIY kits ...
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Boost converter in series with buck LED driver

What I want: Drive a 17V, 600mA COB LED from a 5V 3A USB powerbank. Approach 1: Use a boost LED driver. I have looked through Digikey as well as manufacturers' parametric searches to find a suitable ...
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Avoid leakage current

I use an opamp driver to pump several amps through an LED. My circuit is below. simulate this circuit – Schematic created using CircuitLab When the input is low, I see a small leakage which I ...
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LED Driver IC Current Setting and Switching Frequency

I have this Boost LED Driver IC and this IC is new to me. So, I require some help on how to set the current for my LED String of 300mA. 9LEDs with each forward voltage of 3V and forward current of ...
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Is Adafruit's recommendation for led strip driver MOSFET incorrect?

Adafruit's article ( https://learn.adafruit.com/rgb-led-strips/usage ) states that transistor IRLB8721 can be used with 3.3V or 5V gate voltage to drive LED strip. However, in IRLB8721 datasheet ( ...
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Buck controller MOSFET drive voltage

I am trying to design a switching regulator for LEDs, which uses the LM3405 as controller. This IC uses the BOOST pin to power the internal MOSFET driver, which controls an internal MOSFET. There are ...
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880 views

lowering current of a constant current driver

I have a constant current led driver which gives 180ma @24volts. But I need 120ma to drive a led strip at same volatge. Is there any way to lower the current from this driver? I tried shunting led ...
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How to read datasheets effectively to connect components safely?

I understand that many questions have been posted regarding datasheets, but I hope that you can help me with my question as well. If I want to know how many infrared LEDs (SFH 4780S) can be driven at ...
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Why this LED strip is emitting light if any driver output wire alone is connected to either one of its terminals but only near the floor?

I was experimenting with LEDs, when I encountered the following strange behavior: 5 LEDs on a strip simultaneously emit light when I connect eny output wire from a mean well +36V 700mA constant ...
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Switching circuit for driving LED at different current values

simulate this circuit – Schematic created using CircuitLab Above schematic is for limiting current to 4A when battery is connected to LEDs. Datasheet of LED(BXRA-56C5300H 50W) are 23.5 Vf and 2....
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Understanding the application of a switching regulator as a constant current LED driver

There is an application note from ON-semiconductors which provides a few diagrams to use a well known MC34063 switching regulator as LED driver. it's around the idea of setting the 1.25v feedback ...
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PAM2804 Lithium-ion single cell LED driver fails

UPDATE (2021-Jan-16) - All working as expected - Project link for anyone to build or do as they please. PAM2804, I've been trying to use this chip for a single Li-ion cell flashlight project, but it ...
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PWM dimming using the TLC5916 current limiting LED driver

I'm using a TLC5916 which is a constant-current LED driver. I want to dim a LED and have setup a simple board with a particle chip. Try as I might I don't get the LED to be dimmer without flickering (...
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Power Supply for LED Array [closed]

The circuit I have attached is basically LED arrays with some transistor and N channel Field-Effect Transistor. It requires 17v, 400mA to work. I will only glow either white led or RGB. They won't ...
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Maximum current through an LED

I have these LEDs for which the max current was not specified. However I know that the voltage is 3.2V-3.6V and the power is 1W. Is it correct to assume that the maximum current is therefore 0.27A ? ...
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Digitally-controlled 0-10A constant current source for driving LEDs

I'm looking to build a circuit to drive single high-power LEDs. The circuit will be controlled from a series of TTL pins: one for enable/disable, and ~4-6 to set brightness via current. The LEDs ...
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2k views

How to programme constant current of a LED Driver for various current levels?

I need to design a backlight unit that will change its duty cycle and constant LED current via a microcontroller. My supply is a SMPS with 12V - 20A output. I need to drive 16 * 16 = 256 LEDs(seperate ...
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UDN2981 maximum output current too less

For a LED 'matrix kind of' project I want to use UDN2981's for sourcing, and ULN2803's for sinking. I want to use 5mm LEDs, being able to use 100 mA (10% duty cycle). Since the ULN2803 can handle ...
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206 views

Multiple Parallel LED Drivers with Single Thermal Derating NTC Thermistor

I am looking at powering Some multi color High power LEDs e.g LED engin LZ4 or LZ7 (probably a string of five) using a tps92691 based Circuit these being high power leds it seems wise to include ...
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879 views

modify 30W LED driver for variable current output

I have a typical flyback converter for an LED chip rated at 30W output. My goal is to change the brightness of the LEDs using a microcontroller. If I am not mistaken (please correct me if I am wrong)...
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963 views

Understanding LED driver circuit AC to DC conversion

I am recently working on mains socket outlet type LEDs lights. They all have very similar AC to DC conversion circuit. simulate this circuit – Schematic created using CircuitLab C1 is a X-2 ...