How many leds can 3v power

What I really meant to say was the more voltage you have left after adding all the forward voltages of he leds in series and subtracting them from the source voltage, the larger a resistor you would need. In other words, if you use a 3v battery with one 1.

I screwed up my example though cause 1. So 3v would light one led in series, and 9v around four. Well you can only put 4 in series, so the 5th one has to be off by itself. Which means that one will be getting the full 9v, and it will need a much larger resistor in series with it to dissipate the heat. The wizard will take care of this for you though.

It will show you a bunch of possible circuit designs, and one will be with the number of leds on each string balanced as well as possible. But that does mean you might still end up with 3 leds on oen string and 2 on another, so you will still need two different resistors if you want the leds to have the same brightness.

Thanks Harris. Harris Deutsch aka dr laugh drlaugh4u gmail. Here is some info on connecting the in series All the LEDs connected in series pass the same current so it is best if they are all the same type.

The power supply must have sufficient voltage to provide about 2V for each LED 4V for blue and white plus at least another 2V for the resistor. Posted: Jul 30, am 0 Hi electronics enthusiasts. Sent from my Typewriter. Posted: Jul 31, am 0 Mvmagic, thankyou very much for your help. Rupert Bair Inner circle? Posted: Jul 31, am 0 A nail file works wonders for diffusing the light.

Arizona Posts. Posted: Jul 31, pm 0 If you want to run a bunch of LEDs, it is more important to have capacity, not voltage. Posted: Aug 1, am 0 The local craft stores in my area have small strings of LED lights that run on a little battery pack, all ready to go, they are used to make light up decorated clothing, so the pack is flat using watch style batteries.

Thanks beanwaur and shark for pointing this out. I took my resistors and placed them in front of the positive lead of the first LED that was wired in series and hooked them up to the battery and once again, there was LED light!

With three different combinations of LEDs and battery power supplies and no puffs of plastic smoke yet things were looking good - aside from my little confusion between wiring resistors in series and in parallel. Unlike LEDs that are wired in series, LEDs wired in parallel use one wire to connect all the positive electrodes of the LEDs your using to the positive wire of the power supply and use another wire to connect all the negative electrodes of the LEDs your using to the negative wire of the power supply.

Wiring things in parallel has some distinct advantages over wiring things in series. If you wire a whole bunch of LEDs in parallel rather than dividing the power supplied to them between them, they all share it. In short, wiring in series divides the total power supply between the LEDs.

Wiring them in parallel means that each LED will receive the total voltage that the power supply is outputting. And finally, just some warnings It also only works if all the LEDs you are using have exactly the same power specifications.

OK, now onto to actually doing the thing. I decided to do two different parallel setups. The first one I tried was as simple as it could be - just two 1. I connected the two positive electrodes on the LEDs to the positive wire coming from the battery and connected the two negative electrodes on the LEDs to the negative wire coming from the battery. The 1. This set up is not pictured Both of the 1. If there were more LEDs connected to the battery, they would draw even more current from the battery and drain it even faster.

For the second setup, I decided to put everything I had learned together and wire the two LEDs in parallel to my 9V power supply - certainly too much juice for the LEDs alone so I would have to use a resistor for sure. To figure out what value I should use I went back to the trusty formula - but since they were wired in parallel there is a slight change to the formula when it comes to the current - I.

I ended up just repeating the mistake that I made in the last step again though, and wired them together in parallel by mistake and so the two Ohm resistors only ended up providing 50 Ohms of resistance. Again, these LEDs were particularly forgiving of my mistake - and now I have learned a valuable lesson about wiring resistors in series and in parallel.

This is the safer better way to wire LEDs in parallel with resistors - and also ensures that you don't make the mistake that I did accidentally. While I didn't actually end up making anything besides a couple of lit LEDs, this information can be used to make all kinds of cool things!

The take away concepts hopefully were: - Power a whole bunch of different value LEDs using the same basic principals. This was the most basic kind of walk through for LEDs possible - and I learned a whole lot along the way. LED arrays and wiring schemes can get significantly more complicated - but for the most part, LEDs are pretty simple to work with, and with relatively little knowledge I was able to light them up - all be it if I sent a little too much juice through them towards the end of the experiment.

I don't fear the LED now. They are my friends. I purchased an OPEN sign. It failed. Many leds in series. Please note for all beginners. When you have lots of Leds in series it is like a Trade Union. I have 2 LED lamps that they are 6V each. How can I connect them to a 12V source? Just connect them in series? Reply 10 months ago. Yup, assuming the 12V source is regulated in some way. For example, I know the "12 volt" power supply to my old slot-car track put out considerably more than 12V, especially with a capacitor across the terminals.

A 12 volt car battery charges on something like 14 volts, so in a car it might need to withstand that voltage, but by itself it's My semi-educated guess is that any battery setup rated at a nominal 12 volts would be OK.

If you want to use a 12V "wall-wart" power supply, I'd want to check it with a voltmeter before counting on it. Do you have extra LEDs?

You can mix colors in parallel if you calculate the correct resistor for the gnd side. A red with a small resistor and a green with a larger resistor. When designing your project it is also worth noting that if a number of LEDs are spread out a long way, then the LEDs furthest from the battery will be slightly dimmer than the LEDs nearest it. Please note that the electronics are not water resistant and should not be washed. So, you've established that you'd like to introduce a number of LEDs to an item of clothing but your first question is: can the item be washed once you've sewn an E-Textiles circuit to it?

The answer is yes , but there are a few extra steps that you have to take when assembling your circuit - the battery holder and any switches must be removable , which is simple enough to do! It should only be the conductive thread and the LEDs that get washed. Please make sure that you dry everything properly before use. The best way to do this would be to attach the cell holder to a separate piece of non-fray fabric with a metal popper on either end As for the circuit that you're stitching onto the garment, sew two metal poppers where you would have positioned the coin cell holder, like so below.

The cell holder is now ready to be connected to the rest of the circuit using the metal poppers. Join the negative popper in the circuit to the negative popper on the cell holder and join the positive popper in the circuit to the positive popper on the cell holder. This process of joining the coin cell holder to the circuit acts as a switch: when connected, the LEDs will light, when removed the LEDs will deactivate.

As well as acting as a switch, this also means that the cell holder can be removed from the circuit to allow for washing. The garment with the LEDs and the conductive thread can be washed by hand in cool water.