What is the USB cable lump for?

[Lord Loh.]

I have noticed that some USB cables have got a lump near the connector while some do not.

What is the lump shaped device for? And what is inside it ?

Also I noticed that the cables with good devices had the lump while the ones whith low end devices did not have them.

My cannon camera had them while my PDA and the web cam did not.

**broken link removed**
**broken link removed**

The URL

Also while searching for the above pic I found one site write...NOT FOR MAC... I thought the USB specifications are universal.

 

[gam]

what is lump on usb cable

Hello,

Usually this "lump" is a ferrite filter to filter any external or self induced interference, this is sometimes necessary for longer cables to achieve the maximum possible data transfer speed.

These filters are available in a lot of other interface cables: (telephone and netork (RJ-11 and RJ-45), monitor cables, etc.

For the "Not for MAC" I think the cable and physical interface is universal but the device using the USB may have firmware that is not compatible with MAC Operating system.

regards,

GAM

 

[layes2]

what is that lump on a usb cable?

some for hub some not