Help need in USB or PS2 cable Extender

[Mazi]

hi all

I'm looking for schematic to extend USB or PS2 cable length more than 20 meter.
according to usb.org the cable length must be under 5 meter.

please help me.

 

[Sceadwian]

You could probably do a PS2 cable that long if you used thicker gauge wire than normal, noise might be a problem though so shielded cable would be wise, only way to find out is to try it. Low speeds USB might work at that distance, again only way to find out is to try it, the 5 meter cable length is only to stay in USB specs, low speed devices (like keyboard and mice) may work. They do make USB repeaters so you may be able to do two 10 meter cables with a repeater in the middle. Doing a repeater every 5 meters is not practical.

 

[Mazi]

Thank you for your answer.but PS2 cable over 10-15 meter has a low signal (some time the keyboard or mouse hasn't any response).The USB cable under 10 meter work good,but when the cable length is over 20 meter it hasn't any response.

 

[Sceadwian]

If a 10 meter cable works on USB then you should be able to use a single bus powered repeater in the middle of two cables to get the desired length. Just out of curiosity, how did you test this? Hopefully with the wire's straight out and back or between the two devices? Just wondering because if you tested it over a short distance with say a coil of wire the results you get don't mean much.

 

[Nigel Goodwin]

Why would you want a 20m lead on a USB keyboard? - generally if you're looking for something stupid, it's because it's a stupid idea!.

 

[Sceadwian]

Nigel, you think simulators are stupid, yet they're not a stupid idea. Give the poster which has expressed an idea for a personal use time to think out the reasons for one or another method working or failing before you call them stupid.

 

[Nigel Goodwin]

Nigel, you think simulators are stupid, yet they're not a stupid idea. Give the poster which has expressed an idea for a personal use time to think out the reasons for one or another method working or failing before you call them stupid.

Considering he's NOT given any suggestion what he's trying to do it's impossible to comment on the exact problem - but as he's asking about using a fixed standard well above it's designed limits 'stupid idea' looks pretty accurate to me?.

I've also NEVER said simulators are 'stupid', I don't use them, and am very saddened by the supposed 'electronics' use of them - but considering you often need to modify your working circuit to make a simulator work I don't see as they are of much use?.

 

[Mazi]

maybe I should explain more what I want to do:I have 5 servers in my office. they have very noise.each server does separate task. the users are confused due to the noisy area.
I want to put these servers far from the users and extend the keyboard ,Mouse and monitor cables.
I found the schematic for VGA that amplified the signals and allow me to extend monitor cable more than 20 meters(standard VGA cable should be less than 9 meters).
Now ,I want the same schematics for extending USB or PS/2 keyboard and mouse cables,too.
There are some devices that do the same functionality(KVM extender),but they are expensive.

 

[Papabravo]

Like Nigel said, trying to apply fixed standards beyond their design limits is a stupid idea. It would be better for you to apply your creative energies in another direction to find a solution.

 

[evandude]

Extending PS/2 would be relatively easy, just connect a microcontroller to the KB/mouse to interpret their data, then use another microcontroller on the PC end to recreate it, with a more suitable long-cable communication method in between the two microcontrollers (RS485?)

However, the amount of time and effort to build something like that would probably not be worth it unless you're already familiar with microcontrollers, PS/2 interfacing, and whatever other communication method you use. Since it's a project for where you work, you should probably consider your hourly wage, and think of how much it will really end up costing if it takes you 10 or more hours to complete - suddenly the price of the commercial solutions may not seem so high - plus they'd be more reliable than a homemade device.

I also agree with Nigel and Papabravo, this sounds like a bad idea. Why can't you just manage the servers remotely, over the network? Telnet, SSH, remote desktop, VNC, or something like that...