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 using a series resistor, or it can get more complicated, involving PWM and multiplexing.
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Two-channel adjustable, mains-powered, 60W LED driver circuit?
Background
I made a nice light for my electronics bench using a tunable LED strip and off-the-shelf driver. The strips have interleaved warm and cool LEDs, and is tunable by adjusting how much power ...
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I have a RBGW LED controller that is 4CH*4A but I need a controller that is 4CH*1.5A. Is there an easy way to make this 4CH*4A controller work?
I have a RBGW LED controller that is 4CH*4A but I need a controller that is 4CH*1.5A. Is there an easy way to make this 4CH*4A controller work? The controller is a PWM controller.
Could I simply add ...
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Running a 3D printer, LED strip, and fan from a 24V PSU
I am working on a project to design an enclosure for my 3D printer. The enclosure is designed, but I am looking for some guidance/suggestions on the electrical side. I plan to add a few strips of 24V ...
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PWM Driver for PIC12F1572
I have rear lights for car (VW Passat) controlled by default with PWM. I want to create another circuit who do like follow:
When I press brake, car send PWM into LEDs and turn it ON. I want to use ...
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Low Percentage PWM LED Brightness (Equation?)
I have a 5 V embedded circuit where a 10 kΩ pot controls the duty cycle of an LED. I noticed that when the duty cycle is only 0.39% (or 1/255 bits), the LED is still perceptibly bright. I'm looking at ...
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Getting current leakage with BS170 MOSFET when switching LED strip
I am trying to make a simple circuit to control an IKEA LED strip (VATTENSTEN, 1.5W @ 5V) with an ESP32 (for use with ESPHome).
For this, I am using a BS170 MOSFET to control the circuit, and it works ...
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LED driver BCR420/1 implementation
I've been trying to design a circuit to control 23 LEDs dimming using a LED driver, but I don't quite understand how they work. Put for example the model BCR420/1:
Datasheet: BCR420/1 Datasheet
I ...
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12v Halogen Wire lighting - Convert to LED [closed]
I purchased a house that has a really cool 12v halogen setup where two wires are suspended across the ceiling in two different locations, and each of which carries four 50W halogen bulbs. Each has a ...
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Turn on/off a LED using a D-FF and a transistor
I'm trying to control a LED using some microcontroller and I designed a circuit using a D-FF and a transistor to handle it. It looks like this:
So I can control when to turn it on or of by simply ...
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TPS61197 IC issues for outer LED driver circuit
In this setup, we've employed the TPS61197 IC to boost the voltage for both the inner and outer LED rings. The inner ring LEDs require separate brightness control from the outer ring LEDs. The inner ...
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LEDs in parallel with no resistors
I know that if an LEDs are to be connected in a parallel circuit, a resistor must be added to limit the current rate flowing through them. But let's assume that I have blue LEDs with rated forward ...
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How to turn an LED on in an inverter circuit
I am currently trying to build an inverter circuit which turns on an LED (on a simulation before building it physically). I am using an 2N3904 NPN transistor, 5V voltage sources, a 220k and a 47k ...
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Addressable RGB LED 'curtain' - how are parallel strings addressed?
I bought a cheap LED curtain device.. its 20x20 fully addressable LEDs. Its pretty nifty, and now I want to make one myself. (in fact, I want to eventually make 20 x 20 x 20 ... but let’s learn to ...
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28V SMPS Supply correction LED
I want to put an LED to see that the input of my LTM8053 SMPS circuit is operational. I have 28V input. I'm thinking of putting 1206 package SMD LEDs, but I'm not sure either. I think it is not enough ...
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Modding a $30 fog machine, driving high power LEDs?
I've recently acquired a $30 fog machine off Amazon that features, next to the obvious fogger, eight high power RGB LEDs, controlled in series via a RF remote. The LEDs are very bright so I assumed ...
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I2C: Can you pull up SDA/SCL lines through an LED?
Everyone likes blinky lights.
Is there any (technical) reason not to pull up the SDA/SCL lines through an LED?
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Why is the green LED not lighting up?
I suppose the green and red are connected in parallel state.
Why is the green one not lighting up?
Why is it not green-1, red-0?
3. I am using a 9V battery. How are the bulbs even lighting up? ...
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"2.4GHz RF" used in some LED lighting products: what protocol is it?
There are a number of LED light control devices about, which boast a "2.4G RF" wireless protocl, which is neither WiFi, Zigbee, nor anything else.
I was wondering if someone could shed some ...
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LED indicator for PWM signal
I want to make a PCB that has an ESP32 on it, and the ESP sends a PWM signal to the motor driver. I want to indicate if the PWM signal is being sent or not by LED, without interfering with the PWM ...
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Control WS2812B LEDs independently
I am using three WS2812B LEDs in my PCB and are connected in series with each other. Is there a way that I can control each LED independently rather than controlling all three together? For example ...
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How to find irradiance of UV LED?
I have a UV LED with the following specifications:
optical watt: 0.103 W
beam angle: 15 degrees
distance from surface: 2.4 cm
Also the circle created at that distance by my calculation is 0.313 cmsq
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Salvaging/splitting up some backlight LED strips to make a lightbox
I'm trying to reuse some old HD425Y1U51-T0L6 LED Backlight LED strips to make a light box.
They look like this:
The closest link I found for them (but no spec sheet) is https://www.shopjimmy.com/...
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Designing boost converter for a supercapacitor source and LED load
I have a 2.7 V 100 F supercap, that would equal 364.50 J of energy based on E = 1/2CV^2. If my load is a series of 4 LEDs with a stack forward voltage of 12 V and forward current of 3 A that would ...
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Replacing LED bulb on a 1.2 V battery-operated solar garden light [closed]
First, I have read some interesting information about 1.2 V battery-operated solar lights on this site. I want to replace the LED bulb associated with a solar puck that I own. It has a 1.2 V ...
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Alternatively blinking two LEDs with 555 Timer
I tried to make a simple 555 timer circuit which turns on one LED when its output is HIGH and turns on another LED when its output is LOW. I tried connecting two LEDs with single 1k ohm resistor (...
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LTspice LED night light voltage problem
I am trying to simulate an LED night light circuit using LTspice. I want to measure the voltage of C2.
The C2 voltage is supposed to be 12 V (based on the textbook), but when I try to simulate the ...
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Low Battery Detection Circuit
I'm trying to light up an LED when my li-po battery level drops below 3 V. I have been using the scheme you can see in the picture.
The only change I have made has been to adjust the values of the ...
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Power supply oscillations when driving LEDs with microcontroller
I driving some LEDs at about 114 Hz with a power supply of 9 V and a max current supply of 150 mA, LEDs are running about 60 mA I have some LEDs in parallel. If I increase to 200 Hz it's the same, How ...
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Battery State Indicator LEDs in Wireless Charging
I am working on a custom wireless charging System. I am using the following ICs
Transmitter IC: https://www.analog.com/media/en/technical-documentation/data-sheets/LTC6992-1-6992-2-6992-3-6992-4.pdf
...
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Why are Lunar White LEDs not a standard part, or what am I missing?
TL;DR: Lunar White is a widely-used standard color in signaling work (like, every pedestrian signal that conforms to ITE specifications uses it, as far as I can tell), so why can't you buy Lunar White ...
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What is the reason behind this circuit's behavior when the switches are in different states?
Just started studying robotics and we were given a couple off tasks without proposed solutions. This is one of them:
A switch in off-state will be called 0 and the on-state will be called 1. So \$S_1\...
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Dim a 158V DC Led
I bought a led lamp and it's too bright. When I saw the converter, it's not a standard 12 or 24 VDC one. it's a 120-215 VDC; Picture attached. I didn't trust that. Borrowed a multimeter and checked, ...
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How to interface buzzer with LED in this circuit
Below is the circuit where I want to integrate the buzzer with the red LED.
The task is to add the buzzer, where the red LED is, in such a way that when the red LED (which is driven by the LED driver)...
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Circuit with push buttons, transistor and LED
I have this circuit. The purpose of this circuit is what SW1 and SW2 are inverted push buttons so when the are pushed they are off. But for me the problem is what buttons are not operating separately ...
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Driving LED with PMDXB600UNE MOSFET from FPGA, MOSFET never turns on
LED was placed rotated 180 degrees during assembly.
So now my question is will this circuit work or should I change it in anyway?
I do realize similar questions have been asked, but I think my problem ...
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Difference between DM13A and TLC59281 Constant Current LED sink Drivers
I was using DM13A driver in my old PCB designs and it was working perfectly using Arduino Mega. Due to parts shortage at JLCPCB I had to use TLC59281 driver for my new PCB. But TLC59281 is not working ...
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LED lights on Christmas card without coin battery?
I’m an elementary / primary school teacher and I would like my students to be able to create Christmas / holiday cards with LEDs, using either copper tape or graphite pens (like circuit scribe) … BUT ...
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Turn on LED for fix time when box is closed
I have a box which is used to put PCB in it when we are not using PCB. I want to turn on a UV blue LED for 1 minute when box is closed to cleanout the inside of box. I cant use limit switch as I don't ...
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Control 2 LEDs with 1 switch
How can I control 2 LEDs?
Requirement is:
Position 1: LED1 is ON
Position 2: LED2 is ON
Position 3: LED1 and LED2 both ON
Preferably using only 1 switch (not the DPDT ON-ON-ON switch).
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Animating 3600 neopixels with RPi is slow
I have SPI RGB led strip with three wires connection:
– TX1818 driver (manufacturer says “it’s compatible with TM1812, UCS1903, SM16703, WS2811–2815”)
– 12V, 9.3 W/m, 5060, 60/metre
– 3600 pixels, 60 ...
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Two LEDs don't light up together [closed]
Why do two LEDs not light up together simultaneously?
Microcontroller is atmega328p. Output voltage 5 V 200 mA
LED 20mA
When I replace LED by single cable, LED doesn't light up too.
LED lights up only ...
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What lithium battery should I use to power a paper circuit using copper tape and a 5mm LED?
We are making paper circuits at school. The students will be making a circuit using double-sided copper tape, an LED (in various colors, R/Y 2.0-2.2 volts, B/G/W 3.0-3.2 volts) and a power source.
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Latching with MOSFET
I am struggling to have the circuit below working on LTspice. Indeed, as I understand it when the switch is pressed the LED should change it's state (turn on if off / turn off if on). The switch is ...
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Blue UV LED Timer Circuit
I have designed a PCB for mouth guard device and also its enclosure is ready in which PCB will be placed when its not in use. I want to use a UV blue light for UV sterilization inside the box. Now the ...
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50 watt high-power LED current problem [duplicate]
I am using this 50 watt high power LED:
.
And want to power it using this voltage booster:
From 12 V to 34 V as the requirements of the LED datasheet.
Will it work?
I read that I need to limit the ...
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Why does the LED turn off when I touch the insulating part of the wire?
This is a NAND gate IC. I have one input connected to the positive terminal of the battery while the other input is not connected to the battery as you can see in the image.
Why does the LED turn off ...
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How do I calculate the area 1.5cm away from a LED with a 120 degree beam?
I have a SMD2835 IR LED with dimensions of 0.28cm X 0.35cm and beam angle of 120 degrees.
How do I calculate the irradiation area if it is e.g 1.5cm away?
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Wireless Keyboard RGB backlight design
I am designing a split wireless keyboard with a 3.7V 2000mAh LiPo battery and using the BQ24075 for power management. I'm contemplating the use 32 of the SK6803 Mini-E for backlighting. Is this ...
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Driving an LED with a P-MOSFET or op-amp as a current limiter and no resistor
I have an application where I need to be able to drive an LED without a resistor. Adding a resistor is not an option. I then must be able to blink the LED on or off by shunting to ground.
LED Specs: ...
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Replica Board of Samsung Horticulture Gen2 Module
I want to make Replica board of Samsung Horticulture Gen2 Module but with smaller form factor.
I am using 42× LM301H (Full spectrum) and 8× LM351H LEDs.
IF of LM301H is 65 mA and IF of LH351H is 350 ...