hello guys, I would like to build a y-usb cable to power the dac externally (more for fun than for real necessity).
I can't find certified USB cables sold by the meter but I found among others, this belden 9829 cable...it is a low voltage cable for computer, for rs232/422 application, twisted pair,double shielded, 100ohm impedance. so it seems to me that it has many of the features of a usb cable.
Here the Datasheet:
https://catalog.belden.com/techdata/EN/9829_techdata.pdf
do you think it would be okay?
I would use only 1 pair of Wire, for data, and just the negative for the common ground.
The second option is to buy a cheap usb certified cable and cut off the ends, like a lindy cromo.
thank you so much
I can't find certified USB cables sold by the meter but I found among others, this belden 9829 cable...it is a low voltage cable for computer, for rs232/422 application, twisted pair,double shielded, 100ohm impedance. so it seems to me that it has many of the features of a usb cable.
Here the Datasheet:
https://catalog.belden.com/techdata/EN/9829_techdata.pdf
do you think it would be okay?
I would use only 1 pair of Wire, for data, and just the negative for the common ground.
The second option is to buy a cheap usb certified cable and cut off the ends, like a lindy cromo.
thank you so much
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The quoted Belden cable seem to have a characteristic impedance of 100 ohm. (From memory) the impedance between differential DATA+ and DATA- wires should be 90 ohm, respectively 45 ohm to ground from each DATA wire. You may experience transmission data problems with the Belden cable. Can't youcheck with the Seller or a appointed Belden distributor...?
Yes 100 ohm.
But usb 2.0 specs tell the impedance must be 90ohm + or - 15%.
90+15%=103ohm, so i thought 100ohm was right.
The 100 ohms for the belden cable is a nominal value, they don't give a tolerance I could see, but I wouldn't expect it to be exactly 100 ohms so you could still run into problems with it.
What about cutting the end(s) off of a spare USB cable? I've done this quite a bit for various projects, its not hard with a little practice.
I've also put a thin strip of kapton tape on the 5V contact of a USB connector, to isolate 5V in the USB cable.
Randy
What about cutting the end(s) off of a spare USB cable? I've done this quite a bit for various projects, its not hard with a little practice.
I've also put a thin strip of kapton tape on the 5V contact of a USB connector, to isolate 5V in the USB cable.
Randy
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