An LED (Light Emitting Diode) emits light when an electric current passes through it.

If the LED module I am using has 3 leds, (2 reds and 1 white) do I add the total value of the volts and mA’s? is it just important to use a resistor that is big enough to not fry the LED's and then it is ok to over that by a little?does the recommended resistor vale just mean at lest that value or higher it does not have to be exact does it if we are talking in terms of going over not under right?

The LEDs have to be placed in 3 rows of 10 and I want to use us less resistors as possible. Reply The easiest way is to use one of the online calculators provided below.All the calculators in step 2 are just doing some simple math that you can do at home:

This is a late answer, but will be helpful to others.

Annoyingly curious.

on sir, can i use any IC or bridge circuit type somthing to glow LED buld? Reply Reply 3 years ago 5 years ago

I suspect the voltage referred to here is AC, while LEDs require DC. on So I am helping a student who has built something with 4 different colored LEDs (that she wired in parallel with copper tape. CUTEQUEEN TRADING 4PCS 50W 6Ohm LED Load Resistors for LED Turn Signal Lights or LED License Plate Lights or DRL (Fix Hyper Flash, Warning Cancellor) …

on i want use Led bulb in real electric circuit for indication at 230 volt. Reply how much resistance is require to protect led???? on I just want to help her get it lit with a battery. The simplest circuit to power an LED is a voltage source with a resistor and an LED in series. We are learning a LOT as we work through trying to educate ourselves on this so thank you in advance for your assistance. Read it, and you will have your answer!Hi, I am trying to rig up a single LED for an aircraft, 24 volt system, breakout box. 5 years ago Your recently viewed items and featured recommendations 2 years ago This is what we know about the LEDs: Red, yellow are 1.8-2.2 v; Blue & Green are 2.8-3.2v. I need to have a LED light that will withstand higher current applications.

About: Creative swashbuckler.

It will be tested between 2 banana plug sockets. Please help meSo, I want to add 30 LEDs. ?24v DC to led red green yellow which resistance best life for led Step 1 - subtract LED voltage from supply voltage.

6 months ago ok so how come i bought a set of led fairy lights from the dollar store and there is no resistor in them, there are 10 white LED's wired in parallel with a battery box , in the box is just a switch and holder for 2 AA batteries ,no resistor anywherethey are small LED's with a flat top , last year i cut apart a string of them for a halloween project and confirmed there was no resistor,i used an AC to DC power supply to power them instead of the battery box with an output of 3.3v DC from an old sony discman, not sure the mA current outputi also plugged the power supply into a plug in electronic lamp dimmer the slide kind with a triac inside and dimmed it a little ,some of the LED's i guess burnt out after a while after about a few weeks or so and got dim, not completely burnt out ,but dimmed ,i also have a halloween wreath pre-lit with similar LED's but yellow orangish,the LED's are clear but emit an orange yellow light,in the battery box for that there is a resistor and it also runs AA batteries,3 of them but i power it with the same power supply setup ,i wire it through the battery box so i use the included resistor it is wired in parallel with the other fairy lightsso how come the dollar store fairy lights have no resistor but the wreath does?why do the fairy string from the dollar store not have resistors?i bought some white LED's from ebay (clear but emit light with a bluish hue)they say VF 3.2-3.4 IV 12000-14000 , not sure what the 2nd thing isi plan on using the same power supply setup, i have some 270ohm 1/2 watt resistorsso will i be ok if i wire say 12 LED's in parallel ,and use one of these resistorsin series between the power leads and + terminal of the power supply?the wreath i have has only one resistor in the battery box so i assume they are only using 1 resistor for the whole string of about 20 LED's, but i see that on another site it is recommended to use one resistor for each LED, but i if use one resistorcan i just multiply the value for each of the LED resistor values i get?for example when i calculate what resistor value i need using a vf of 3.2 and a power supply voltage 3.3 i get recommended to use a 5 ohm resistor ,so if want to use 12 LED's wired in parallel then can i just use one 60 ohm resistor in series between all the positive led leads wired together and the + of the power supply?instead of wiring a 5 ohm resistor in series with each individual LED? The ballast resistor is used to limit the current through the LED and to prevent that it … and would a 270 ohm be overkill or should i look for a 60 ohm resistor or just use more led's?
And it needs to stay small, like for on top of a mini banana plug grounding plug. How do I do this? I need help very badly. Reply 20 mA all. That makes sense to me. 3 years ago Answer

6 months ago on Be aware that mains power is rated at "230V rms", which means peaks of 325V.Supposing a 3.5V 25mA LED, you would need a 12860ohm 8.03W resistor. 6 months ago

on if i use small stepdown transformer and zener diode to control voltage for LED than? Can anyone advise us?