Hi! So check out this crazy idea:
I have a firewire device (an audio IO box) that I want to power from my laptop, but since PC laptops don't provide power over firewire, I wondered if I could power it via my USB ports.
I am very much an electronics beginner, barely familiar with Ohm's law, etc, but I'm a technical dude, so i get arrogant and think i can figure this stuff out. Don't let the following jargon fool you.
My idea:
Take four USB cables, plugged into the four USB ports on my laptop. On the other end of each of them, cut the head off, clip the data lines off (unused), take the power lines and wire them in series. 5V at .5mA max per connection (my understanding of max USB power) = 5V at 2mA, 10W max output.
This goes into a DC/DC converter to take it to 12 or 15VDC.
The box, according to tech support, comes in at "12V, 1.0 amp & 8W", which doesn't exactly line up unless 1A is just the max draw, but given other things I've read I think it's basically an 8W device, can take 12-24 VDC, and briefly draws extra current on startup resulting in like 10 or 12W.
Here's the DC/DC converter I was looking at:
https://www.mouser.com/search/Refin...CC10-0512-SF-E&N=1323038&Ntk=Mouser_Wildcards
Data sheet at:
https://www.tdk.co.jp/tefe02/ea335_cc_e.pdf
(the CC10-0512-SF-E is the particular one i'm looking at, either 12 or 15V selectable)
It's 84% efficient, so from 10W that's 8.4W, so that may well be enough to power the device... ???
Among 1000 things i don't know about what i'm getting into are the following concerns:
- if the 4 USB ports on my laptop are truly separate "hubs" and therefore each able to supply that much power in tandem
- even if they technically are, if they will actually supply that much power, given the power regulating algorithms that some laptops enforce (and since USB devices are supposed to "ask" for that much current)
- if the DC/DC converter will cause problems in the laptop's power system (either by drawing so much or having weird back-interference...) or otherwise hurt the computer
- if the DC/DC converter will cause problems in the audio device for similar reasons, especially since DC voltage conversion (i've read) can cause "noisy" power supplies...
I have a Dell Inspiron 6000.
Any thoughts, corrections, grave warnings, mocking responses, welcome.
Especially welcome are posts of the "here's a simpler, more elegant, more effective solution" nature.
Thanks for your time!
-c
I have a firewire device (an audio IO box) that I want to power from my laptop, but since PC laptops don't provide power over firewire, I wondered if I could power it via my USB ports.
I am very much an electronics beginner, barely familiar with Ohm's law, etc, but I'm a technical dude, so i get arrogant and think i can figure this stuff out. Don't let the following jargon fool you.
My idea:
Take four USB cables, plugged into the four USB ports on my laptop. On the other end of each of them, cut the head off, clip the data lines off (unused), take the power lines and wire them in series. 5V at .5mA max per connection (my understanding of max USB power) = 5V at 2mA, 10W max output.
This goes into a DC/DC converter to take it to 12 or 15VDC.
The box, according to tech support, comes in at "12V, 1.0 amp & 8W", which doesn't exactly line up unless 1A is just the max draw, but given other things I've read I think it's basically an 8W device, can take 12-24 VDC, and briefly draws extra current on startup resulting in like 10 or 12W.
Here's the DC/DC converter I was looking at:
https://www.mouser.com/search/Refin...CC10-0512-SF-E&N=1323038&Ntk=Mouser_Wildcards
Data sheet at:
https://www.tdk.co.jp/tefe02/ea335_cc_e.pdf
(the CC10-0512-SF-E is the particular one i'm looking at, either 12 or 15V selectable)
It's 84% efficient, so from 10W that's 8.4W, so that may well be enough to power the device... ???
Among 1000 things i don't know about what i'm getting into are the following concerns:
- if the 4 USB ports on my laptop are truly separate "hubs" and therefore each able to supply that much power in tandem
- even if they technically are, if they will actually supply that much power, given the power regulating algorithms that some laptops enforce (and since USB devices are supposed to "ask" for that much current)
- if the DC/DC converter will cause problems in the laptop's power system (either by drawing so much or having weird back-interference...) or otherwise hurt the computer
- if the DC/DC converter will cause problems in the audio device for similar reasons, especially since DC voltage conversion (i've read) can cause "noisy" power supplies...
I have a Dell Inspiron 6000.
Any thoughts, corrections, grave warnings, mocking responses, welcome.
Especially welcome are posts of the "here's a simpler, more elegant, more effective solution" nature.
Thanks for your time!
-c