Does it draw current to power the usb when no usb device is connected?
1169291
Yes, the USB charging circuit in this outlet does use power even when nothing is plugged in. I tested by wiring a Mastech MS8264 digital multimeter in series with the hot lead that powers the outlet. With nothing plugged into the outlet, the multimeter read 0.42-0.44 milliamps at 120VAC. Note that this is not a true-RMS multimeter; the actual power draw was probably more like 0.66 milliamps. That's less than 1/10th of a watt, which might be so little that it doesn't matter to you, but it is definitely nonzero and does add up over time. For comparison, I also measured a FastMac U-Socket, a competitor to this device. The U-Socket reading showed about 2/3 of the current that this one drew (with nothing connected to either device). I chose to keep this one because it is easier to fit into a gang box and seems to have a sturdier USB port design.
1169292
It only draws current when a device is plugged in and using the USB power. You can leave USB cables plugged into the ports and the outlet will not draw current until those cables are connected to a device that attempts to use the USB power. (In theory a device could stop using the USB power once charged, and the outlet would no longer draw current, but very few devices are designed this way.)
374663
Mine doesn't. It still provides power until the device stops requesting it. It would waste power. If you want to see the status, just click the button again.
1255034
It appears to work powered by the AC adapter or the USB 3.0 cable alone. My USB 3.0 external hard drive works without the AC adapter. However in order to charge attached devices like my mobile phone, the AC adapter has to be plugged in.
2039301
As it uses an external power supply (not just power from the USB port), the power would remain on. I plug mine into a multiple power outlet device which I turn off after shutting down the computer and so the power will not be on all the time.
179255
No, power goes into the unit, not out of it. The "USB input" on this device is for power only, it is "micro-usb."
1966745
Its here on my desk top right now, thus it is easy to verify your question. NO, the unit immediately went off line and disconnected. Upon application of the power it came back on line. I selected this unit for two reasons:USB 3.0 and the higher current capacity. I have in the past been frustrated with "low cost" hubs that won't charge a phone for example.Hope this helps.Michael
445370
No-- the device essentially turns a single usb port into a multi function peripheral that is feeds the appropriate signal back into the primary cpu. It has its own power supply and remains on even when computer is powered down.
1966747
Its here on my desk top right now, thus it is easy to verify your question. NO, the unit immediately went off line and disconnected. Upon application of the power it came back on line. I selected this unit for two reasons: USB 3.0 and the higher current capacity. I have in the past been frustrated with "low cost" hubs that won't charge a phone for example. Hope this helps. Michael
2005815
It draws very little current. I have driven 2 off usb power. If running from a micro controller such as an Arduino, you will need to connect to 4 I. O. Lines and 5v and gnd. Do a search on Google. There are plenty of tutorials on running it as well as some libraries that can be downloaded.
1623167
The short answer is yes. The unit has an on/off switch. The USB cable will charge it while off and charge/power it when on.
2043310
The manufacturer says this: When the hub's power adapter is not connected, the hub is capable of running purely from bus power (from the host PC). When a hub reports itself as bus powered to the OS, the OS looks in the USB descriptors for every attached device, sees how much power the device reports that it needs reserved for it, and pops up a error (and possibly disables devices) if the total amount of power requested exceeds what a bus-powered hub in theory can count on pulling, which is 500mA for USB 2.0/1.1. We recommend always using the power adapter for best results.
2159678
It does power down after a period of inactivity. If you request information there is a 1 to 2 second delay then it responds. It still uses an external power supply as opposed to the trend of USB 5 volt power.
862202
It works without power supply when attached devices have little power consumption but peripherals such as an external hard drive that draws power from the port requires the added boost of the external power supply.
1014757
Nope. Looks like the USB ports are not powered while in recharge mode, even though the recharge port is dedicated to recharging.
1433011
To the best of my knowledge, powered USB riser will not work without being powered. Although I have not tested it myself.
1272887
No, it will need to get power from USB cable. Meanwhile, it will also need to get signal and drawing through computer's support.
59497
It is powered through the USB port. Just plug into the USB port and it is ready to work.