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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Lamp interference and dimmability
In one apartment in two neighbouring rooms I have two LED light sources. One room has a lamp with power supply shown on the picture below that powers 28 LEDs. The other one is ESP32 controlled SSR ...
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How to Choose a LED with the Proper Lumen Output for a Handheld Decoration?
I am currently developing a handheld Christmas tree PCB decoration. On the front, it will have roughly a dozen green SMD LEDs in the shape of a Christmas tree. However, the shear number of options for ...
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What might be the exact circuit of 'auto-changing' LEDs in a lead-acid battery charger? [closed]
What is the circuit that turns OFF the red LED and turns ON the green LED, after the lead-acid battery (given below) reaches the 14.1V while charging? This circuit is connected at the last part of the ...
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How can I calculate the power efficiency of an SMD LED? (% converted to light and % converted to heat)
I am designing an LED matrix for an LED lamp. I need to calculate the heat dissipation from all LEDs which is the dissipation of one LED times their number to choose an appropriate heat sink.
The ...
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How to achieve constant LED current when switching another load with transistors
I'm building a formicarium to have below my monitor. With a Pi pico 2 W as controller, powered by a USB3 port on the monitor.
I'm a software developer, but new to electronics.
The schematic below is ...
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LED chaser 555 timer in astable works only when shorted
I build a simple LED chaser that will be powered from a 9 volt battery and will start with a simple slide switch. I have simulated the design in TinkerCAD and it worked the way I wanted. However when ...
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How to design a single-wire synchronization topology for multiple LED flashers?
Hello,
I want to design a blinking LED module that can run stand-alone, but also synchronize with other identical modules over a single shared SYNC wire.
The behavior I’m trying to achieve is:
Each ...
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MCP73831 Lithium Ion Charger -- STAT LED stays off
As part of a project, I have implemented a charger circuit based on the MCP73831 charge controller to keep a 3.7V Lithium Ion battery charged via a small solar panel (5V, 350mW max output):
The + ...
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Accidentally Burned PCB While Soldering — Is It Still Usable? [closed]
Can I still use this? This is an LED driver I accidentally burned during soldering.
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PCB LED Connection
We were tasked to make a LED series and parallel connection on PCB from scratch. We need to connect 7 LEDs in series, and 8 LEDs in parallel wherein we need to use toggle switch. Our source will be a ...
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Does a resistor in series with an LED draw more power than a resistor alone?
Basically the title, but I wanted to check my intuition and math on the subject here, just to be sure.
If I have a 10 V source, a 1kΩ resistor, and an LED with a \$V_{f}\$ of 2V, I would expect the ...
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Unexpected slope change in I–V curve of an infrared LED — beginner question
I’m a complete beginner working on a simple experiment to measure the I–V characteristics of LEDs.
For most visible LEDs, my results look as expected: the current increases exponentially once the ...
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Current limiting for high power LED array
I'm working with a group designing some high power LEDs for DIY stage lighting. We purchased an 800W multi-color array chip on board made by Tyanshine (Data sheet: http://www.txled.com/uploadfiles/...
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Is it advisable to apply a square voltage (for example a PWM) to LEDs?
I intend to connect the output of a push-pull type buffer IC, SN74LVC2G34, to:
a) a LED (for debugging and monitoring purpose)
b) a gate driver IC (1ED3142MC12H)
I simulated the following circuit to ...
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Why is a dummy starter for a LED fluorescent tube resistive?
I bought some dummy starters that are used to replace the original starter in a fluorescent light fitting when a LED replacement tube is fitted. I broke one starter open, and it appears to have a fuse ...
