Tagged Questions
3
votes
1answer
52 views
calculating resistance for LED strips to use as parking lamps and turn signals
I'm installing LED strips in my car's tail lamps to convert it from conventional bulbs to LEDs. I have a understanding of what I'm doing but not the complete knowledge to make the circuit work ...
1
vote
2answers
63 views
how many resistance do i need to safe the LED of PC814?
if i have a input of 5v (arduino HIGH) on the LED of a PC814, how is the value of the resistance that i must use before that, so i don't burn the led?
...
4
votes
4answers
777 views
Driving LEDs at long distance
I'm looking to drive 52 LEDs (datasheet), around a large inflatable tent. The LEDs have a forward voltage of 3.3V, at a maximum of 20mA.
I'm thinking of using the NXP SAA1064 I²C 16-channel LED ...
6
votes
1answer
499 views
Requirement to display 3 mm LED by 220 V AC supply
I want to power a single 3 mm LED by a 220V AC source. For this I think I need one LED, one resistor and one capacitor. I don't know the needed resistor value and circuit diagram. The circuit also ...
1
vote
2answers
2k views
Connecting LEDs to a 9V battery
1) I have 6 4.5V 20mA LEDs and have connected them to a common 9V battery. Doing this I made 3 parallel circuits with 2 LEDs in each.
Now, I see that most pages that describe LED circuitry say that ...
3
votes
3answers
162 views
wirewound adjustable resistor. Something I missed?
I am by no means an expert on electronics, but I thought that I had a fairly good grasp of the basics. That is, until 10 minutes ago.
1 picture ~ 1000 words, so here is what I have:
The yellow wire ...
5
votes
2answers
236 views
What would the current be if I plug an LED into a perfect circuit
If I had an LED that had a forward voltage of 2.2 volts with a forward current of 20mA and I somehow created a battery that was exactly 2.2 volts and I put that LED, and only that LED, on that ...
10
votes
2answers
2k views
Correct formula for LED current-limiting resistor?
I'm trying to work out what value resistor to use in a LED circuit. The equation I'd use to do this is:
$$ R = \frac{V_{cc} - V_f}{I_f} $$
Seems logical, and makes complete sense. The answers to the ...
4
votes
4answers
7k views
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 ...
12
votes
4answers
537 views
Simple Circuit Question
I've been playing around with an Arduino for a while now, and while I know just enough about simple circuits to get little projects up and running, I still don't know enough to figure out what's going ...
