dsc106 Posted March 17, 2008 Share Posted March 17, 2008 Is that normal, for the USB port not to allow power for thumbdrive? What DOES the apple keyboard allow you to use with it? What doesn't it support? Why? Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/ Share on other sites More sharing options...
A Nonny Moose Posted March 17, 2008 Share Posted March 17, 2008 Some will work with the keyboard and some won't. It just depends on the kind of thumb drive and how much power it needs to suck out of the computer to make it work. Basically without additional power somehow, it will only work with very low power items. Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670007 Share on other sites More sharing options...
bigboss Posted March 17, 2008 Share Posted March 17, 2008 Some will work with the keyboard and some won't. It just depends on the kind of thumb drive and how much power it needs to suck out of the computer to make it work. Basically without additional power somehow, it will only work with very low power items. Yup one limitation with USB is the relatively low voltage (5V) and since part of that 5V is going towards supplying the keyboard, there simply isn't enough power. Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670017 Share on other sites More sharing options...
scj312 Posted March 17, 2008 Share Posted March 17, 2008 IIRC almost anything should work if you use it with the keyboard hooked up to an aluminum iMac. Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670029 Share on other sites More sharing options...
dj_stick Posted March 17, 2008 Share Posted March 17, 2008 i had the AL keyboard hooked up to my hackintosh and real mac pro and managed to run the following with no problem: Keyboard Midi Hubble (3 port usb hub/midi interface) iLok eLicenser Mighty Mouse and a microsoft mouse Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670129 Share on other sites More sharing options...
Falcon351 Posted March 17, 2008 Share Posted March 17, 2008 USB can supply 500mA at 5V per port, so the keyboard, its hub and all bus-powered devices plugged into it have to be under that limit. Also, I think the keyboard hub supports Full Speed max (at least the one supplied with a PowerMac G5 at work 3-4 years ago did). You may prefer to have HiSpeed capability for a flash drive. Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670184 Share on other sites More sharing options...
Ongeloof Posted March 17, 2008 Share Posted March 17, 2008 I always thought that the USB drives on the AL keyboard were 2.0 drives, as i have no trouble running my time machine external on it. Think Mark Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670319 Share on other sites More sharing options...
consolation Posted March 17, 2008 Share Posted March 17, 2008 Yup one limitation with USB is the relatively low voltage (5V) and since part of that 5V is going towards supplying the keyboard, there simply isn't enough power. The voltage ALWAYS stays the same, unless you have a faulty component. The limiting factor is the amount of CURRENT that's available. In a DC circuit V*A=Power, usually expressed in Watts. Each USB port is limited to supplying up to 500mA for a total draw of 2.5W. So, since the kb takes up 100mA that leaves 400mA available at the two ports as the best case scenario (for example my mouse uses 100mA, so my free kb port can have a load of up to 300mA or ~ 1.5W.) I say best case scenario, because if the kb is connected to a USB header that has another device on it the amount will be lower. In my experience mobo manufacturers usually connect 2 ports per header, these ports usually SHARE the 500mA allowance (although strictly speaking each port should supply 500mA.) Cheaper mobos can have more USB ports on each header, I encountered one where all 8 ports hanged off the same bus. Flash drives vary greatly in quality, generally the cheaper ones will require more current as the components are of poorer quality; so, just because one works doesn't mean they all will. This also depends on how they deal with power, a device initially asks for 100mA then increases the load in 2mA - some cheap ones just escalate to 500mA, no matter what their actual needs are. Powered hubs and devices help to alleviate this problem, at the expense of requiring an external PSU. This is where fire-wire has an enormous advantage, it can supply up to 45W at 9~30V, unfortunately this makes it much more expensive. I always thought that the USB drives on the AL keyboard were 2.0 drives, as i have no trouble running my time machine external on it.Think Mark All Al ones are 2.1 Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670470 Share on other sites More sharing options...
Ongeloof Posted March 17, 2008 Share Posted March 17, 2008 Think Mark Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-670716 Share on other sites More sharing options...
macprogrammer Posted March 21, 2008 Share Posted March 21, 2008 Is that normal, for the USB port not to allow power for thumbdrive? What DOES the apple keyboard allow you to use with it? What doesn't it support? Why? You can use a USB "thumbdrive" with the Apple Keyboard if it is connected to the Aluminum iMac. Link to comment https://www.insanelymac.com/forum/topic/94015-apple-keyboard-not-enough-power-for-thumb-drive/#findComment-675904 Share on other sites More sharing options...
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