All Questions
Tagged with current-limiting led
60
questions
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Hi! I would like to connect my LED lights (Vaxmyra from IKEA) designed for 24V system into my 12V system, do I need a current limiting resistor?
I bought these VAXMYRA LEDs thinking they were made for 12V but apparently they need to be feeded 24V.
Supposedly I'll have to install a 24V DC step-up converter, but this device can deliver up to 3A ...
3
votes
2
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601
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LED fairy lights with series capacitor?
I've opened up the battery box of a string of fairy lights (like pictured at bottom) and found a resistor, plus what looks like a capacitor in series with the lights. Is this really a capacitor? If so,...
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LED circiuit for a current limited circuit
I have the following requirements for a circuit:
The circuit is supplied from a 500mA current limited voltage source
The circuit should indicate the status of the supply, i.e. if it is in current ...
- 125
0
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1
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337
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Limiting the Current of a Constant Current LED Driver which is Driving a Halogen Bulb
I am powering a 12V, 35W halogen bulb with a MeanWell HLG-100H-20B constant current power supply. The "B" version of this power supply has a really neat dimming control system which lets one control ...
-2
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1
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Do I have to use current limiting resistor for LED in this configuration?
LM741 datasheet says that it can output a maximum of 20-25 mA. So in this case, is that R5 a must, or will it be safe not using it?
Assuming LEDs can withstand 25mA.
- 2,106
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Reducing current in a circuit without reducing voltage [duplicate]
I didn't find a solution in the other similar posts or maybe I don't understand them.
Here is my problem : I've got power supply with an output of 5V and 8A to feed 128 leds drawing 5V and 50mA each. ...
3
votes
1
answer
768
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Why are these LED current limiting resistors so big?
I'm looking at the charging circuit for a lithium ion battery that was made by Adafruit. Here's an excerpt:
If there's a 5V rail from the USB port and a 470 Ohms resistor, is that limiting the ...
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2
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High power LED array
I’m designing SLA 3D printer and I need to design UV LED array for LCD screen backlight. Preliminary design is 5x3 (5 parallel lines with three LEDs in each). All LEDs will be soldered on PCB.
The ...
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1
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1
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4 channel optocoupler [duplicate]
I was designing a dual H bridge board which uses some logic signals to drive 8 mosfets. Initially I was using 8 optocouplers per board which was really annoying to wire up. after a bit of searching, I ...
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1
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How to measure and power an array of unknown RGB LEDs?
I have 5 of these plastic moldings that each have 2 RGB LEDs inside along with a microcontroller that rotates through the color spectrum for aesthetics. I want to bypass the microcontroller so that I ...
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Why my hex inverter chips (all three of them) are not producing a HIGH output with low input?
I wont say I am great at reading datasheets, but I noticed that for 74LS06 chip, Ioh is 0.25 mA and Iol is 40mA. Does that mean it can light-up an LED when its output is low but not when its output is ...
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3
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How to solve for current given resistor value for LED circuit?
So I have the following LED circuit:
I know how to find the forward voltage and current from the datasheet of the LED and how to then solve for the appropriate value of \$R\$.
However, what I really ...
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2
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Overcurrent Protection for COB Leds wired in parallel powered by Const Voltage Mean Well Driver
Roughly this is my current wiring diagram.
The Mean Well driver that I am using is the HLG-185H-36B. Output 36v DC, max current 5.2A. The Cobs are 36V and have a max operating current of 2.76A, ...
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1
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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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3
votes
3
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Current limiting from a USB supply
I am designing a device which must power a number of RGB LEDs. I am currently looking at WS2812 "NeoPixel" style LEDs, which have a max current draw of 60mA each. I would like to have a large number ...
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