Fire alarm systems need to be inspected, tested and tagged annually. Testing must include all smoke detectors, manual pull devices, annunciators, visual indicators and strobes, control units, voice/alarm communications systems and any other devices that are a part of the fire alarm system.
it will need a port like this one to get more power from the usb since it only give 5.0 volts and this powered usb give up12 to 24 volts so you dont have that in a laptop and there is no way it could raise the power on the usb port in a laptop without damaging something .http://en.wikipedia.org/wiki/Powered_USB.
Make sure itâs set to a number higher than the voltage listed on the adapter. Usually you will set the Volt / Multi meter to the number 50. Step Five. Place the tip of the red conductor inside the adapter and the tip of the black conductor on the outside edge of the adapter. Step Six. To know if the correct amount of power is being supplied, look at the needle reading. It should land on the voltage marking near the voltage listed on the back of the adapter. If it doesnât, it may be time to purchase a new one. The A/C adapter is a crucial piece of your laptop. Be sure to test it every now and again to make sure your laptop is getting the power that it needs.