My wife is going on a trip and taking her iPad. She wants to watch movies using the iPad and my portable speaker. The speaker is rechargeable through a computer USB port, and is labeled “5v”. Since the iPad does not have a USB port, the only other way we have to recharge the speaker is a plug I have with a USB port. I use this plug to recharge my phone.
The plug is labeled “12v”. What will happen if I give her the plug to recharge the speaker? Success? Breakage? Pretty sparks?
More likely than not, without knowing the speaker model and the internal circuitry, you risk damaging it by applying excessive voltage, possibly including exploding capacitors and batteries (or maybe it uses a regulator/charger chip that can handle more than 5 volts, but the input capacitors might be only 6.3 or 10 volts, common standard voltages for a 5 volt circuit). Otherwise, the 12 volt plug would have the same pin configuration as a standard 5 volt USB port, assuming that it is in fact a USB plug since making a 12 volt USB plug (USB expects 5 volts) is asking for trouble.
Maybe a stupid question, but does it plug into a wall outlet, or into a car power socket? If the later, the 12 V could mean the input voltage. I looked at all the USB chargers for our phones, and they all have two voltages listed: 110 V AC in, and 5.0 or 5.1 V out.
USB is 5V. there are nonstandard power adapters with the USB style plug that output 12V, i’ve seen these in 3rd party products designed for Apple products or other products.
get a power adapter that outputs 5V, they are inexpensive.
I have never seen a USB port that provides 12 V, that would be dangerous. If you’re looking for a charger, I use the Innergie 15W charger http://www.myinnergie.com/mMiniAC15/default.aspx and it charges everything I’ve thrown at it.