Car USB power with hold on.

302

04:17:01

The top switch is the ignition turning on and the bottom switch is the feed from the rev counter (engine running). The capacitor charges up enough to turn on the transistor in about 1 second. This will switch on the FET and current will flow into the load. I intend switching down to 5V to supply USB devices (phone, tablet, etc.)
This allows the engine to be cranked and started before turning on devices. The addition of the feedback holds the power on until all power is removed.

published 11 years ago

ETJAKEOC

11 years ago

Tablets require 15V buddy

RocksOfSteel

11 years ago

Well the 3 tablets i have charge and run from 5V micro usb ports. Are you thinking laptop pc maybe?

ETJAKEOC

11 years ago

iPad's and Android tablets require 15V in order to enter charge mode, unless it's a kindle type of tablet or along the lines of those

RocksOfSteel

11 years ago

No, you're mistaken. All three of my Android tablets and my Android phones will charge from 5V. Can't comment on the. IPad.

hassanqais

11 years ago

My android tablets asus transformers 101 15V

RocksOfSteel

11 years ago

http://www.ebay.co.uk/bhp/android-tablet-charger-5v

barron

11 years ago

Every thing i have phone, tablets 5v usb and since usb is only 5 Volt's makes sense. But my wife has a zoostorm 10.1inch that charges at 9v on a barrel plug it must have to batteries in series i imagin.

ETJAKEOC

11 years ago

Asus Prime is 15V, but it's also a power house tablet

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