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.
6,570 questions
3 votes
3 answers
177 views
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 ...
- 341
3 votes
3 answers
121 views
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 ...
- 33
-2 votes
0 answers
97 views
why is my inductor + led not working [closed]
I made a circuit in which there are 2 coils one connected to a push button and then the a dc power supply on the other coil there was a LED and a resistor. When I powered the circuit and pressed the ...
6 votes
1 answer
350 views
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 ...
- 63
2 votes
8 answers
971 views
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 ...
- 79
2 votes
1 answer
142 views
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 + ...
- 259
-1 votes
1 answer
137 views
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.
3 votes
2 answers
165 views
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 ...
- 43
10 votes
8 answers
1k views
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 ...
- 397
5 votes
1 answer
107 views
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 ...
0 votes
3 answers
125 views
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/...
7 votes
4 answers
1k views
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 ...
- 210
0 votes
2 answers
98 views
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 ...
0 votes
2 answers
87 views
Connecting 2 COB in parallel [duplicate]
I have 2 COB chips rated upto 400ma at 36v connected in parallel with a 600ma constant current driver (54v max) On testing both led worked fine but had minor difference in lumens at some levels as I ...
- 9
0 votes
2 answers
100 views
How reliable using this LED under its rated specs?
I want to control the built in LED of this switch by an MCU GPIO pin which 3.3V. The datasheet of the switch is given here. Since there is almost no detail but the "Voltage & Rating: 12V @ ...
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