Linked Questions
31 questions linked to/from Correct formula for LED current-limiting resistor?
25
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Why we use 330 ohm resistor to connect a LED? [duplicate]
Possible Duplicate:
Correct formula for LED current-limiting resistor?
Why we use 330 ohm resistor to connect a LED ?
I mean:
the R is by practice 330 ohm.
Why this value? How do I calculate ...
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0
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1
answer
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Connecting nine LEDs in series.. why the results? [duplicate]
I asked this before but I'm having problems still. I need to connect nine LEDs in parallel with a 9 volt battery. The wire leading away from the 9V separates into three and on each three are three ...
- 39
1
vote
1
answer
572
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Connecting an always on LED to a raspberry pi [duplicate]
I'm new to electronics, so I thought I'd start simple and just connect an LED to the GPIO on the raspberry pi, to pin 1 (3.3v) and the ground pin.
But I'm having trouble calculating the resistor I ...
- 457
3
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1
answer
318
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Is a resistor needed for LEDs in this beatbox project? [duplicate]
I'm making a LED beatbox (seen on Kipkay.com). I'm using 8 LEDs (5 millimeters, I don't know if this helps) and my power source is 12 VDC 800 mA. Do I need to add a resistor? If yes, which one should ...
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-2
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1
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LED's too dim. Wrong resistor? [duplicate]
I'm a halloween tinkerer, and I have these UV/Blacklight flashlights that I use in my decor, but they eat batteries like crazy. They start going dim within an hour or so.
So, since I already have ...
1
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2
answers
234
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What resistors do I need for my LED? [duplicate]
I don't really know the whole technology thing so this is why I'm asking.
I bought "20PCS 5mm IR infrared LED 940nm Lamp High Power" for head tracking and I don't know what resistors will be good for ...
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-3
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1
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101
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I want to wire a single led off a motorcycle battery [duplicate]
I want to use my motorcycle battery to power a single led that has a maximum voltage of 3.6 volts. what resistance do i need to drop the voltage from 12 volt to 3?
2
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2
answers
74
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What is the resistor for 3 watt green led in series [duplicate]
3 green leds (button leds) are connected in series. Using 12 volts car battery and a simple current limiting using resistor, avoiding constant current. Good heatsink is used. No standard spec is ...
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0
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1
answer
85
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Lighting LEDs from high current source [duplicate]
I have an circuit with six high torque servos connected parallel to power brick that provides 5V @5Amps. Everything is running fine. But I wanted to add few LEDs to circuit but I dont know how do I do ...
-2
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2
answers
97
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Help with simple Circuit [duplicate]
I am hoping that someone can help me to calculate voltage and current to the LED socket. I see that there are 3 batteries in series, plus a resistor (?). Thank you very much.
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0
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1
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How much voltage I need to light up this led [duplicate]
I have a RL80-UR543 LED 8MM. How much voltage I need if I use a resistor of 100Ohm?
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157
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4
answers
77k
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How can I efficiently drive an LED?
I understand that I can not connect an LED directly to a battery because it will draw too much current. Thus, there must be something else in the circuit to limit the current.
What options are there? ...
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13
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4
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63k
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How do I calculate the resistor value for a simple LED circuit?
I have a simple circuit:
The max rating (current) of the LED is 30mA.
How can I work out what the resistance of the resistor needs to be? By using ohm's law I found it to be \$3V/0.03A = 100 \Omega\$...
- 457
11
votes
4
answers
14k
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Voltage drops and current for LED?
I created the following circuit on a breadboard and used the Arduino Uno 3.3V supply for the power supply:
...
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16
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3
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Why use LNAs in a noise generator?
In this Maxim appnote the avalanche noise of a zener diode is amplified by two cascaded LNAs (Low-Noise Amplifiers):
You can guess what my question is: why use low-noise amplifiers if you want ...
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