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Usb Charger Answered

I have 2 questions; 1.) Does anyone know if I can use a resistor in a usb charger? If so, what bands.(ex red,blue green, ect). 2.) Can I use an 3v LED to reduce the power to 6v. Would 6v harm my electronics?


3v is just how much voltage is needed to power the LED, but you can run several 3v LEDs off of 3v.

It really depends on what the device needs -- although don't you charge iPods from USB?

What im tring to say is, I don't have access to a 5v regulator. Do you know if 6v is o.k. for a usb operated device? And, I charge my ipod with the cable that came with it.

I wouldn't risk it with 6v... Do you have zener diodes? You can use those to drop down the voltage...

isn't that really inefficient because you'r shorting the battery out? I've never been sure about zeners, in series (for example in this situation) would it only allow 5 volts through? Or if you have a 7 volt supply it just allows 7 volts through. or if your have a 7 volt supply it only allows 6.3 volts because of the junction. Which brings me to a point, you could just use a diode, it'd bring it down to 5.3, still risky though.

Wait, why would a normal diode bring it down? And you're oversimplifying the zener situation, since they can be rated for different voltages, right?

yeah, I'm over simplifying. a silicon diode drops 0.7 volts across it because of the pn junction

5V is standard for most electronic devices. With 6V, you are running the chance of frying your device. Are you sure you can't gain access to a 5V regulator?

do you know anything that would have a 5v regulator in it?

Sorry, no. If you can't purchase one online, then if you can travel to a Radioshack you should find one there.

Why don't you just get a commercially made charger. I picked up a wall and a car charger (and a cable I put on graigslist) for only $10. its usually not that cheap to make one.

zener diodes? Is that like a regulator?

No, its a diode that only lets certain voltages through, but it can be used to chop down voltages.

do you know what would have a zener diode in it