geekhack
geekhack Community => Keyboards => Topic started by: silverphoenix on Mon, 19 September 2011, 12:34:24
-
I'm thinking of modding a KBC poker with LED's but I would like to know what the power draw (amperage) your average keyboard has.
The USB power output is 500mA max, and the LED's draw 25mA each but I can use resistors to lower there draw, but I would like to know how much the KB itself draws so I can have a good idea how much I have left over for the LEDs.
-
I couldn't tell you what the specific draw is, but considering Deck, Ducky, et. al. have backlit, fullsize keyboards, I don't think a back-lit Poker would cause a problem.
-
Well the only estimation I can get is Deck has published they run their LED's at no more than 5.25mA, so I can deduce that their kb's use a maximum 500ish mA, which is beyond the usb spec but they probably run lower than that normally.
-
Anyone with a mac? you can use the system profiler to give a pretty good estimate as to the power draw of connected USB devices.
For example, my model m draws more than my WASD. I forgot the exact numbers, though.
I'd say you're still looking at under 200 mA for a fullsize keyboard.
-
I'm using Model M via Blue Cube on a Mac Pro daily and occasionally (when travelling) on a Macbook Pro - never had issues with it and I know old IBM is a power hog.
-
I'm using Model M via Blue Cube on a Mac Pro daily and occasionally (when travelling) on a Macbook Pro - never had issues with it and I know old IBM is a power hog.
Hey czarek your avatar shows a 101 key Model M. Just got my blue cubes from Half-Saint and your post made me realize I could now use my Ms on my MacBook Pro if I wanted to.
Are you really using a 101 key Model M on a Mac? Where and how did you put the "apple" key on a 101 key? I'd like to do just that but I only have 101 or 102 keys Model Ms.
-
looks like a space-saver to me. I don't use mac OS, but I'd recommend remapping the capslock to ctrl or something, and using one of the ctrl keys as command.
-
Hey czarek your avatar shows a 101 key Model M. Just got my blue cubes from Half-Saint and your post made me realize I could now use my Ms on my MacBook Pro if I wanted to.
Are you really using a 101 key Model M on a Mac? Where and how did you put the "apple" key on a 101 key? I'd like to do just that but I only have 101 or 102 keys Model Ms.
Yes until now I was using 101 key 1390131 but now I'm on a business travel in London and apparently my NIB Model M 84-key 1392934 has been delivered so I've changed my avatar.
And yes, even though I live in Europe I prefer ANSI layout. Lack of "apple" key aka Command (that's the name I prefer as I don't like Apple Inc.) is not an issue - I have Alt keys remapped to be Command keys, Ctrl keys remapped to be Options (Alts) and Caps Lock remapped to be Control. I'm so used to such layout at the moment I even tend to remap my 105 keys keyboards (like Endurapro) in similar way. It really does make sense.
-
And yes, even though I live in Europe I prefer ANSI layout. Lack of "apple" key aka Command (that's the name I prefer as I don't like Apple Inc.) is not an issue - I have Alt keys remapped to be Command keys, Ctrl keys remapped to be Options (Alts) and Caps Lock remapped to be Control. I'm so used to such layout at the moment I even tend to remap my 105 keys keyboards (like Endurapro) in similar way. It really does make sense.
Yup, same here... I'm euro too but I prefer ANSI by far. I also remap CAPS-LOCK to act as CTRL... I guess now I'll make some room for the "command" key : )
-
I think I remember more than 100 mA when using my PS2 to USB adaptor. on my model M. I remember wanting to test if it really had more current demands such that some adaptors won't work with it.
-
power draw?
(http://web.media.mit.edu/~silver/drawdio/hardwareNote0.jpg)
depending on the color, you should be able to use resistors to control the amount of draw from the LEDs
-
Keep in mind that the resistors will also waste some power as heat. Blue LED's (with higher forward voltage) will waste less power through the resistors.
I found some 3.2V blue LED's at mouser. Putting 15 mA through them, you only need 1/8W resistors
The cheapest red LED's are 1.7V, and require a 1/4 resistor if you want the full 30 mA, 1/8W for the 15 mA
-
I'm checking my power draw:
Looks like Model M, Blackwidow, and Microsoft are all using about the same amount of power: 100mA.
When I plug in my USB flash drive, that spikes it up to about 250mA. USB port can handle up to 500mA.