jasonlaronde
New Member
I have made a few posts before regarding the building of a relay control module... Rather than start from scratch I decided I could use a 16 port KVM switch I had in the basement! Perfect!!! Push a button, enable a channel, push another button, diconnect and enable another channel... Exactly what I need...
I tied 5v to pin 4 of each of keyboard ports inside thus enabling each channel without actually having to have any channel connected to a computer so now each channel runs stand-alone...
Now all I need to do is pull some juice or a ground from each channel to use to trigger my relays and I'm done...
I wanted to pick the brains of those in the forum before start permanently altering the box beyond repair...
(To give a little background - I'm using a TrendNet 1601D rackmount 16 channel KVM as break-before-make relay control module... Keyboard and Mouse Ports are emulated via an onboard processor in the KVM and the video lines are from what I can tell, simply rerouted.)
Since I'll be pulling from what would be the input of each of the 16 channels of the KVM I can't use the "pin-9" 5v DDC line since I'm pulling from the wrong end. I have used a multimeter and can get about 4.4v from the vsync and hsync pins at 13 and 14 but that's a little low as the lowest coil hi-current relays I can find are a 15A contact at 6v coil so 4.4v won't quite be enough to trigger... 5v will do it... Also I don't know how stable a vsync and hsync line will be under load... Any ideas? Does the monitor put out a 5v signal (or more) as a return that I could then tap on it's way out the KVM to trigger my relay? Or maybe I'm even looking in the wrong spot???
Thanks guys/gals!
I tied 5v to pin 4 of each of keyboard ports inside thus enabling each channel without actually having to have any channel connected to a computer so now each channel runs stand-alone...
Now all I need to do is pull some juice or a ground from each channel to use to trigger my relays and I'm done...
I wanted to pick the brains of those in the forum before start permanently altering the box beyond repair...
(To give a little background - I'm using a TrendNet 1601D rackmount 16 channel KVM as break-before-make relay control module... Keyboard and Mouse Ports are emulated via an onboard processor in the KVM and the video lines are from what I can tell, simply rerouted.)
Since I'll be pulling from what would be the input of each of the 16 channels of the KVM I can't use the "pin-9" 5v DDC line since I'm pulling from the wrong end. I have used a multimeter and can get about 4.4v from the vsync and hsync pins at 13 and 14 but that's a little low as the lowest coil hi-current relays I can find are a 15A contact at 6v coil so 4.4v won't quite be enough to trigger... 5v will do it... Also I don't know how stable a vsync and hsync line will be under load... Any ideas? Does the monitor put out a 5v signal (or more) as a return that I could then tap on it's way out the KVM to trigger my relay? Or maybe I'm even looking in the wrong spot???
Thanks guys/gals!