Using USB To Switch

[porto99]

I was using the parallel port to switch on/off a relay - 3.5V output on the data lines. But during startup the lines of the parallel port chatter (BIOS test and resetting them).

Now I was thinking of using the USB port, but not seen any examples of using this port.

Could the USB port be used to switch a relay?

Or is it the case of buying a PCI card to provide a discrete to switch this relay.

Any suggestions please,

Porto.

 

[xwb]

Have you tried going into the BIOS setup and disabling the parallel port? Some BIOSs have this feature. I don't know if that will work or not and whether hitting the IO port will still activate your relay. It may work on your PC.

I did that many moons ago on my 286 and it worked but I no longer have that PC or the relay hardware so I can't try it on my current PC.

 

[zeitghost]

What operating system are you using?

If you want to use the USB port, you'll need some sort of USB peripheral to connect to the relay.

There's a cheap & cheerful Velleman kit K8055 which has 8 digital outputs and 5 digital inputs. Plus 2 analogue ins & outs.

rgds
Zeit.

 

[porto99]

Intend to use Windows 2000 and XP Pro.

We were using the parallel port, but get chatter during startup, the same chatter seems to affect the serial port also. Hence the interest in USB ports.

Any suggestions, just need to drive a relay when the PC is powered on!

 

[HyperEngineer]

Can you do anything with hardware? Such as putting a fast charge slow discharge circuit between the serial or parallel port and your relay? The circuit would consist of two diodes, a resistor, a capacitor and the relay.

HyperEngineer
If it ain't broke, it probably needs improvement.