USB printer switch circuit design sharing

This is a USB Printer Switch circuit design with two USB input ports and one USB output port. This is a very simple device that allows two computers (desktop/laptop) to select a USB printer or some other USB device such as an external flash drive, memory card reader or scanner. The rotary switch selects the PC you wish to use the USB device with while two LED indicators indicate the selected PC.

The most common way to share a USB printer between two PCs is to use one machine as a print server. However, this is not always convenient, as it means that the server PC must always be on if you want to print something.

That can be a hassle if you just want to quickly fire up the other machine and print something. It also means the two PCs have to be connected together either via a hub/router or directly via an Ethernet crossover cable.

Another approach is to use a dedicated USB print server. However, as before, it must be connected to an Ethernet network along with the PC. Such devices also require their own power supply and typically cost over $100, which is cost-prohibitive if you just want to share a USB printer between two computers for occasional printing in a home setting.

That's where this simple device comes in. It's basically a 2-way switch box that lets you manually switch a USB printer from one PC to another as needed. The switching is performed using a rotary switch, while two LEDs on the front panel indicate which PC is connected to the printer.

USB Printer Switch Circuit Design

This method has several advantages. First, you don't need to network the two computers. Second, you can print from one machine while the other is turned off. Third, the device does not require power.

USB Printer Switch PCB Design

The circuit uses switch poles S1a-S1c to select either USB receptacle CON1 or CON2 and connect its pins to CON3. The fourth pole (S1d) selects either LED1 or LED2 to indicate which PC is selected.

This USB printer switch is assembled in a box with a total of six holes: two for USB-B (CON1 and CON2), one for USB-A (CON3), two for the LED indicators, and one for the switch selector.