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Questions tagged [led]

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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33 views

Easiest way to power a led remotely

I was wondering what is the easiest and cheapest way to have a powerled (3 Watt) turn on/off and blink remotely from a distance (60m-100m). I've been looking at some microcontroller solutions, simple ...
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1answer
55 views

Classification of LED type

Out of curiosity, I recently opened a damaged measurement device (it´s some kind of lab spectrometer, but I am not sure) that contains a LED with a package like I have not seen before (see picture). ...
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52 views

Connecting 5mm 30 led bicolor(red, blue) In a series supply through AC 230v [on hold]

so please help me in my project. I want to make like christmas decorations light, or diwali light, I don't know who to change AC 230v into DC, so please tell me who I make bridge rectifier circuit ...
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1answer
24 views

Led strips power supply , consumation and contorller

Hello everyone i am really bad at this stuff, i tried reading a few articles but i can't seems to understand anything. So basically i bought the LED strips from aliexpress that came without power ...
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0answers
41 views

Switchback LED wiring for car

I have two types of turn signal switchback LED (white orange) that has three terminals each, one LED has one positive and two negative terminals and another LED has two positive and one negative ...
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1answer
23 views

Hooking into Qi charger status LED to power something more

I have a Qi charging module and I want to light up a higher-power string of LEDs when my phone is charging through it. The module has a blue status LED to show it's charging, which I think is where ...
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3answers
66 views

How does an IR LED turn on and how can I test to see if its not broken?

I'm an electronics beginner. Does an IR LED turn on like how regular LEDs turn on or does it only turn on when you've assigned a specific code for it to transmit? The reason why I ask: I bought ...
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1answer
18 views

Dimming LED with speed controller

I'm trying to controll 4 parallel 12V DC LED strips with an speedcontroller. I am able to dim the lights from 100% lit to about 5% lit, but it never turns them off completely. My multimeter can't ...
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1answer
27 views

Microbit - Control an LED that is powered externally

this may be a bit of a noob question but I am trying to make a motion activated light with my Microbit. I have a 1W superbright LED and its clear the Microbit won't supply the current needed for this ...
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1answer
59 views

Questions About BJTs in My Circuit

I have an LED multiplexer circuit (inspired by https://www.instructables.com/id/Multiplexing-with-Arduino-Transistors-I-made/) in which I have set the resistor values to maximize the current through ...
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2answers
57 views

LEDs with same current rating but different forward voltages

I have scoured the net for a direct answer but people always end up talking resistor because they don't have constant current. I have a constant current power supply. LEDs are 700 mA and vary ...
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2answers
76 views

How do I model a digital out in a circuit simulation?

I have a PIR: Panasonic NaPiOn AMN34112 that has a digital output. When it detects motion it outputs 4V and 100 uA max. I want to connect this output to a LED using one or more transistor amplifier ...
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1answer
46 views

LED Controller + LED Panel with common cathode

I have a 3-CH DMX controller (5-24V, 5A/ch, common anode) from amazon (don't know if links are desired here) and a 12V 100W MCPCB LED panel, which unfortunately has a common cathode. The panel is ...
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1answer
36 views

Infineon DAVE v4.2.2. XMC1200 Boot Kit 4-Channel DMX Issue

I am using Infineon Dave v4.2.2. to program the XMC1200 boot kit with colour LED card to read a DMX input signal using a rotary dial. For those that don' know, Dave uses a simple UI with "apps" that ...
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0answers
51 views

I need help with LED multiplexing [closed]

I am required to create a 10 x 10 LED matrix display. I researched for more than two days and I am still confused which LED driver i should use. I do not know how to use LED drivers or transistors, I ...
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2answers
48 views

Impact on led driver supply voltage more than its rated voltage [closed]

What is the impact on driver if its input supply voltage continuously more than its rated input voltage? Will it lead to driver failure in the long run? Thanks,
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1answer
51 views

Series circuit LED controlled by Arduino schematic question

I'm currently making a project with multiple series circuits to PWM control multiple LEDs. I have figured out how to make it work with a transistor, however I was curious if this way would work as ...
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2answers
89 views

How can I use an LED driver (QX5252) to light up 3 different color LEDs (Green, Yellow, Purple)?

I am trying to light up 6 LEDs with the common garden light circuit (2v Solar panel and 1.2V battery). The problem is that I want to light up 2 yellow LEDs, 2 green LEDs, and 2 purple LEDs ...
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1answer
87 views

How can I generate 3 outputs (green/red/off) with a single toggle switch (VERY SMALL)

Disclaimer - I have little to no knowledge of any of this. I'm in over my head and appreciate your help and I appreciate in advance the lamens terms you've chosen to answer with. I'm trying to ...
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2answers
1k views

How to solder Christmas lights insulated wire?

I want to fix Christmas lights like these, whose wires got cut near the batteries. The LEDs near the batteries still work. I tried touching the wires from the two parts and I was surprised that the ...
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2answers
41 views

Dual rail power supply for audio needs to drive LED too, unsure of design approach

I have a +17V, -17V power supply for a headphone amp I am building, I would like an LED to indicate when the amplifier is turned on, but don't want to negatively effect the audio output by drawing ...
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1answer
107 views

Need help connecting PIR to LED

I have a Panasonic Pir Motion Sensor (AMN34112.) I want to connect it to a LED so that the LED lights up when the sensor detects motion. I need some help to make sure I do not destroy the PIR. The ...
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3answers
52 views

Base resistor on transistor

I am new to electronics and creating my first big project but I am stumped on figuring out the value of the base resistor (R2 in diagram) of an NPN 2n3904 transistor. All of the LED are rated for 20mA....
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0answers
44 views

First LED of a LED ribbon powered by a WIFI socket flashes [closed]

I build an Ambilight system for my computer and I'm using a Raspberry Pi to control a LED ribbon with SPI communication. A power strip is used to power A Raspberry pi to control the LED ribbon with ...
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1answer
33 views

adding a push button on LED string lights

im looking at making a flower in a glass dome with string LED light for a present. the problem is most stings had a on/off switch. Is there a way to attach a push button on/off to it and not have to ...
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2answers
143 views

Is the circuit in this answer wrong?

In the Q/A link below, the circuit in the answer seems to be wrong to me. Answer to "How to gradually light up an LED?" Circuit: simulate this circuit – Schematic created using CircuitLab In ...
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1answer
51 views

Need help understanding PNP Base into NPN Collecter circuit for LED Array

I am a novice in circuitry and I'm trying to make an 8x8x8 LED Cube using an instructables guide for a school project. I have ordered all the parts and was testing the grounding circuit for each layer ...
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1answer
60 views

Should I spread the pads out on the footprint of a THT LED?

I have a 4 pin RGB LED with a common anode. I'm trying to make my first PCB and I am creating the footprint for the LED now. I don't have a datasheet for the LEDs unfortunately. I have a ruler ...
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3answers
45 views

Connecting a single LED to Motherboard CHA Fan Header

I've been reading that it is possible to connect a LED to the motherboards CHA fan controller. The LED I had in mind was this Online people have been saying you would need a resistor as the voltage ...
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3answers
124 views

How to stop LEDs from dimming in small circuit

I wired up a simple circuit (below) which was designed using the "Every Circuit" website/app. It's a small LED circuit used inside a costume prop. When the master switch is pressed, the 3 LEDs light ...
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2answers
79 views

What LED driver should I use

I am wiring up a house where the kitchen has multiple LED strips. All I have is a wire hanging out of the light strips. And as the LED lights are built into the cabinets I cannot get inside them to ...
4
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1answer
112 views

Dim 20ma LED in retrofit application

I've done a day of research and haven't found a clear path to my problem. I thank you for taking the time to help! Retrofit application in 1985 VW Jetta (MKII). My instrument cluster lights, the ones ...
2
votes
1answer
160 views

Can I power this LED circuit from 5V USB powerbank?

I have an old flashlight that says "15W Police Waterproof" on the handle, the battery compartment is normally for 3 type C batteries, unfortunately the bottom battery leaked and is stuck in there. ...
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2answers
80 views

Attaching a 3 mm fiber optic cable to a WS2812 LED

I am wondering how to easily attach a side-glowing fiber optic cable (I have 3 mm here) to a cheap WS2812 LED that is flat and soldered onto a PCB (like these here). I tried with Sugru, hot glue, ...
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3answers
148 views

LEDs in computer case are non-polar?

Normally I think of LEDs being polar and having a definite current direction, the "D" in LED standing for "diode". However, in working with with a computer case recently, the front part of the case ...
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1answer
63 views

LED light cycles on and off - Is it a heat or voltage problem?

I have this LED light that was over the aquarium at my work desk. There's a circuit board (not pictured) that controls when the lights go on and off but, after a power outage a few weeks ago, it seems ...
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2answers
91 views

What happens to the semiconductor in an LED when it is given voltage that it cannot handle?

Let us suppose we have an LED with the allowed voltage range of 1.5V to 4.5V and we gave it somewhat 12V. Now we know that the LED will instantly stop forever. But I want to know what will happen to ...
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4answers
52 views

Does the switching frequency and ON/OFF time duration of LED affect the power consumption of LED?

I want to drive the electronics consisting a controller with different peripherals on its I/O pins, one of which is LED, with 3V coin cell battery supply. I want to determine if its switching ...
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0answers
26 views

Dimmable 120V AC LED bulbs intermittent brown out?

I have 5 dimmable LED light bulbs hooked up through a common fixture to a dimmer. Roughly every minute or so, the bulbs will dim in unison slightly for about 1 second, the come back up. I have ...
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0answers
39 views

Isolated vs non-isolated boost converter for LED (12v to 24v)

I have a 12v system in my motorhome and planning on installing 24v LED strips, however, I'm unsure whether I would need an isolated or a non-isolated boost converter. I'll be using roughly 5 meters ...
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0answers
16 views

PSOC 5 turning on a LED with a switch

I'm trying to turn on a LED using a switch and then turn off the LED after 5 seconds with PSOC. With I run the firmware I wrote, the LED is on and then turns off after 5 seconds. What I want is that ...
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2answers
45 views

Using less than 10 LEDs on LM3914

The LM3914 IC has a divider that works over 10 LEDs. Does this IC enable using less than 10 leds and does it automatically adjust the scale based on the number of LEDs (eg 5)?
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58 views

LED, zener voltemeter

5 LEDS ...
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2answers
43 views

How to add red led light to my white led lights

What’s the best way to wire the red led to this system? I have it now hooked up to 1 300 ohm resistor & each two white led lights out of 4 hook to 200 ohm resistor. The entry unit is powered by 3 ...
6
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2answers
115 views

LED as light sensor not properly working in circuit

I read some articles about using an LED as a light sensor. I chose an IR LED and checked the voltage levels produced in different light situations resulting in about 200-300mV in full artificial light ...
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3answers
180 views

How can I create voltmeter with Zener diodes?

simulate this circuit – Schematic created using CircuitLab 5 LEDS One LED is to remain always on when current is passed through. One LED will turn on when voltage is between 50 to 90 volts. ...
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2answers
68 views

Control dual color LED without microcontroller

I have a latching, SPDT switch with dual color LEDs (the first page of the datasheet), that can either be Red or Blue depending on the polarity of the voltage. I would like them to be one color when ...
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4answers
1k views

Voltage across LED and source when LED is floating from one end

Refer to these pictures and can you explain why is there 3.335V coming across LED and the LED isn't even turning on. Also to note is that changing the resistor value does not change voltage at D2(A2) ...
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0answers
18 views

How DMX512 controller work with 5-in-1 RGBWWW led strip [duplicate]

Recently the 5-in-1 RGBWWW led strips are hot, I'm wondering whether the DMX512 controller can work with these tapes? Tks. The specification: https://drive.google.com/file/d/...
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2answers
63 views

How much current will this LED draw?

Sorry if this is a really basic question - software engineer here, so I'm a little out of my element. I'm working on an IoT project, and I'm planning on using this button with a red LED inside of it. ...