How do I add a USB device to my computer if I am out of ports?

Just about every peripheral made now comes in a USB version. Here's a list of some of the USB devices that you can buy today:

Most computers that you buy today come with only one or two USB sockets. With so many USB devices on the market today, you easily run out of sockets very quickly. For example, on the computer that I am typing on right now, I have a USB printer, a USB scanner, a USB Webcam and a USB network connection. My computer has only one USB connector on it, so the obvious question is, "How do you hook up all the devices?"

Advertisement

The easy solution to the problem is to buy an inexpensive USB hub. The USB standard supports up to 127 devices, and USB hubs are a part of the standard.

A typical USB 4-port hub accepts 4 "A" connections
A typical USB 4-port hub accepts 4 "A" connections

A hub typically has four new ports, but may have many more. You plug the hub into your computer, and then plug your devices (or other hubs) into the hub. By chaining hubs together, you can build up dozens of available USB ports on a single computer.

Hubs can be powered or unpowered. As you learn in How USB Ports Work, the USB standard allows for devices to draw their power from their USB connection (all USB cables contain two wires -- for +5 volts and ground). A high-power device like a printer or scanner will have its own power supply, but low-power devices like mice and digital cameras get their power from the bus. The power (up to 500 milliamps at 5 volts) comes from the computer. If you have lots of self-powered devices (like printers and scanners), then your hub does not need to be powered -- none of the devices connecting to the hub need additional power, so the computer can handle it. If you have lots of unpowered devices like mice and cameras, you probably need a powered hub. The hub has its own transformer, and it supplies power to the devices that connect to the hub so the devices do not overload the computer's power supply.

The Universal Serial Bus can easily handle both a scanner and a printer, even if you are scanning and printing at the same time. The original USB supports up to 12 megabits per second, and USB 2.0 supports up to 480 megabits per second -- considering that most devices consume only 6 megabits per second, you can definitely run more than one device at a time.

These links will help you learn more:

Advertisement

Originally Published: Apr 1, 2000

USB Port Extender FAQ

What is a USB port?
USB stands for Universal Serial Bus. It is the most popular type of port used in computers to connect them to external devices such as keyboards, mice, printers, phones, cameras and more. It is common for personal computers to have at least two USB ports.
What is the difference between USB and USB-C?
The main difference between a USB and USB-C connection is that it the latter can charge devices at a faster rate. Most USB-C ports can deliver up to 100 watts of power.
Why did my USB ports stop working?
Common reasons for USB ports to stop working include hardware failure and problems with software incompatibility. Your PC may require updates or the operating system may be missing important pieces of software. In some cases, your USB port may actually be physically damaged.
What is a USB port extender?
A USB port extender is a device that increases the distance at which you can connect a peripheral to a USB port and increases the number of ports available. Most USB extenders draw a lot of power, and thus, drain your laptop battery very quickly.

Advertisement

Loading...