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**ulao** · (This post was last modified: 11-16-2012, 09:17 AM by ulao.)

It's not that there is conflicting info it's that people just like to guess at stuff and have no real idea what they are doing. First you need to know the forward voltage on the leds. No, that is not going to easy to find as you don't know the part numbers. Then you string the leds in series with a known voltage. Just because a power supply says its 7 volts does not mean that is what you have. In every case it's something else ( i.e. 6.4v ). Then you need to find the current the leds are pulling and use a resister to monitor the impedance. All leds will need a resistor or in time they blow. Some leds have resistors build in but you won't find that in cheep stuff. Again you need to know the tolerance of the leds so you don't have too much current flow. Give only the right amount of total current and watch the forward voltage.

Now if that makes sense to you, your are ready to begin. If it does not you will eventually burn something up. This is why us electric engineers get paid the big bucks LOL.

veng3r · 11-16-2012, 09:49 AM **#12**

Can I not just feed it the same or less volts and amps that the Wii does? I just need to know how many volts and amps the Wii gives it and then if the psu I use gives it a bit less then I know I won't burn out the LEDs. It might be dimmer but it should be fine as I'm only a few meters away and there are people getting away with powering them off less than 5v from USB.

To reiterate, could somebody please confirm how many volt and amps the Wii feeds a 10 LED bar?

Thanks for all the help, it's invaluable.

**ulao** · (This post was last modified: 11-16-2012, 10:16 PM by ulao.)

Assuming you mean the usb port the questions is feed what? Since you are making the bar that makes no sense. If you buy a usb bar already made that says it support usb then its going to work off usb from the wii or a computer. In your cases you are designing the bar so the wii would blow the bar just like a usb from a computer?

Maybe you mean the actual wii bar power supply I think its around 7.

The thing you are not getting is that electricity flows from source to device ( + voltage to ground ). So if your source is 5 volts and you pull 2 amps of current that is not the same is pulling 800ma of current. To adjust for the right value you dont just increase/decrease the volts you change the resistor. One more time, you need to know the forward voltage of the LED. If you are getting the leds from an existing bar that was from a usb then stay in the 5 volt range. Do the math and calculate the right resistance. Guessing like you are suggesting is only going to end up bad. If you have the money to experiment like that just buy a 10 led bar?

veng3r · (This post was last modified: 11-17-2012, 01:31 AM by veng3r.)

(11-16-2012, 04:25 AM)veng3r Wrote: I've got an official black 10 LED sensor bar, a Wiimote motion plus limited edition that came with Skyward Sword and a cheap USB Bluetooth dongle.

(11-16-2012, 05:28 AM)veng3r Wrote: Whats the recommended way of running a 10 LED sensor bar off USB power?

(11-16-2012, 08:59 AM)veng3r Wrote: Thanks for the info. It sounds like I'd just be better off giving it the right amount of power it needs as I have no idea how to work that out.

I think my my easiest option is to solder the right kind of power supply to it replacing the lead it comes with. What is the ideal volts and amps to power this with? There seems to be a lot of conflicting info on whether it needs 7v or 12v and I can't find any info on how many amps it needs.

(11-16-2012, 09:49 AM)veng3r Wrote: Can I not just feed it the same or less volts and amps that the Wii does? I just need to know how many volts and amps the Wii gives it and then if the psu I use gives it a bit less then I know I won't burn out the LEDs. It might be dimmer but it should be fine as I'm only a few meters away and there are people getting away with powering them off less than 5v from USB.

To reiterate, could somebody please confirm how many volt and amps the Wii feeds a 10 LED bar?

(11-16-2012, 10:14 PM)ulao Wrote: Assuming you mean the usb port the questions is feed what? Since you are making the bar that makes no sense. If you buy a usb bar already made that says it support usb then its going to work off usb from the wii or a computer. In your cases you are designing the bar so the wii would blow the bar just like a usb from a computer?

Maybe you mean the actual wii bar power supply I think its around 7.

The thing you are not getting is that electricity flows from source to device ( + voltage to ground ). So if your source is 5 volts and you pull 2 amps of current that is not the same is pulling 800ma of current. To adjust for the right value you dont just increase/decrease the volts you change the resistor. One more time, you need to know the forward voltage of the LED. If you are getting the leds from an existing bar that was from a usb then stay in the 5 volt range. Do the math and calculate the right resistance. Guessing like you are suggesting is only going to end up bad. If you have the money to experiment like that just buy a 10 led bar?

OK, I'll start from the beginning and try to explain further. I've got an official black 10 LED sensor bar (I already own) that I want to power (without plugging it into the Wii). I've been told earlier in the thread that USB doesn't give enough power so to avoid changing LED's and/or resistors and the complications that arise with that it looks like my easiest option is to just solder the right kind of power supply to it.

I just need to know how many volts and amps the Wii gives/supplies/feeds the sensor bar. Then if the psu I use gives it a bit less I know I won't burn out the LEDs. It might be dimmer but it should be fine as I'm only a few meters away and its going to be better than running off USB or blowing the LEDs with a 9v battery.

To reiterate, could somebody please confirm how many Volt and Amps the Wii feeds/gives/supplies a 10 LED sensor bar? I.e. How many Volts and Amps does the official 10 LED sensor bar need to work correctly?

I hope this makes sense now. Thanks.

**ulao** · 11-17-2012, 03:02 AM **#15**

Quote:I just need to know how many volts and amps the Wii gives/supplies/feeds the sensor bar.

no clue, lots of conflicting info out there. I tried the same thing and made many educated guessed but I just ended up with bad bars. That fact is you need to know the right information and its just not out there. I had one bar targeted for 7 volts and it lasted about 3 months. After so many tires I just gave up and bought a battery version.

You will need to know the following.

1) the out put volts from the unit.
2) the current the bar requires.

Then find a power supply that puts out that voltage and has at near the same rated impedance.

Look out for.

1) bad info, this is what you will find.
2) a power supply that says 7 volts and its really 6.2

veng3r · 11-17-2012, 03:18 AM **#16**

(11-16-2012, 08:59 AM)veng3r Wrote: There seems to be a lot of conflicting info on whether it needs 7v or 12v and I can't find any info on how many amps it needs.

(11-16-2012, 09:17 AM)ulao Wrote: It's not that there is conflicting info it's that people just like to guess at stuff and have no real idea what they are doing.

(11-17-2012, 03:02 AM)ulao Wrote:
Quote:I just need to know how many volts and amps the Wii gives/supplies/feeds the sensor bar.
no clue, lots of conflicting info out there. I tried the same thing and made many educated guessed but I just ended up with bad bars. That fact is you need to know the right information and its just not out there. I had one bar targeted for 7 volts and it lasted about 3 months.

Thanks for all the help. How many amps did you supply with the 7v on the bar that lasted 3 months?

**AnyOldName3** · (This post was last modified: 11-17-2012, 04:12 AM by AnyOldName3.)

The actual Wii has a power supply rated to 7-12V, so theoretically, anything in this range should be sufficient as long as there are the Amps to back it up, however, this is not the case. Some bars draw almost the full 12V, and some draw almost the minimum 7V. That's why I suggested using a multimeter to test yourself. Because the resistors are large relative to the LEDs, the LEDs usually draw less than 5V, which is why putting in small resistors to adjust the ratio is sufficient to bring the brightness up enough.

If I was simply soldering an actual power supply to the bar, as opposed to changing the bar's voltage requirements, I'd go for a 10-12V one, as that's the most normal range for the bar to lie in.

This almost doesn't look like I missed a full page of posts when I wrote this.

veng3r · (This post was last modified: 11-17-2012, 04:45 AM by veng3r.)

Cheers, I've got a good idea on the volts to give it but how many amps does it need? I thought a 9v battery ran the risk of blowing the LED's but from what you're saying this is sounding like a viable option. I've got a 9v 550mAh battery I could try.

I'm thinking I could plug the sensor bar into the Wii and take a photo to see how bright it is. I could then do my mod, take another photo and check the brightness against the first photo. If its brighter I know its gonna burn out but if its dimmer and still works I should be golden. I can solder but I don't have any other electronics skills or tools so I can't really test it the way you're suggesting.

I'm even thinking of trying to find some female connectors for the sensor bar (maybe from a broken Wii) so I can try multiple ways without butchering the original connector and cable but I guess I could just try it one way and then another re-soldering inside the case of the sensor bar each time and keep the original cable intact.

**AnyOldName3** · 11-17-2012, 05:05 AM **#19**

A 9V battery shouldn't break it, but again I'd feel safer recommending it if I had some current and voltage measurements, or at least knew in what arrangement the insides of the bar are wired, or what the original resistors are.

veng3r · 11-17-2012, 05:20 AM **#20**

(11-17-2012, 05:05 AM)AnyOldName3 Wrote: A 9V battery shouldn't break it, but again I'd feel safer recommending it if I had some current and voltage measurements, or at least knew in what arrangement the insides of the bar are wired, or what the original resistors are.

I can take it apart in a couple of days once my tri wing screwdriver arrives in the post. Will I be able to see what resistors are inside it (i.e will they be marked with info)? Thanks for all the help.