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Network ON/OFF Switch with Timer Answered

Hello there, I am a network administrator and trying to create a simple device to test the alarms on our systems. Since I am not an electrician of any sort, I have an idea of what I need, but no idea of parts or names to order. Basically, I need to have a basic on/off switch with button that I can wire to a CAT5 cable. Simple enough, stops traffic at the push of a button but thats the obvious part. I also need to have some control over how long my connection times out, and after some research, I think a timer relay does that, but I can't be sure. It just needs to turn the activity back on after it goes off say between 1 second and 10 seconds off, the connection turns back on. If I can accomplish that, than I would also like to add a dimmer type device such as that of a light switch dimmer, but smaller and working with less voltage. So... Can this be done with all 3 electric devices? The closest thing I found in searching was some generic Lag Switch, but it did give me a starting idea of how to design it. I drew a simple draft of what I had in mind. Any help by some electric gooroo's would be most appreciated. Thanks! Jonathan

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Can we assume that you know why UTP is T? Pat. Pending

Who's the question geared at? UTP is twisted to reduce interference or "cross talk". But what does that have to do with this posting?

Your suggested circuit isn't twisted. Consequently, noise could create a fault condition even when it wasn't operating. Pat. Pending

The actual connection will only remove a single wire from the Cat5 cable for likely an inch or less. It's highly unlikely that there would be any cross talk as specially considering that the separated line will have no contact with the other 7 wires. But good observation none the less.

I was referring to external noise not cross-talk. If your test circuit creates noise itself or allows external noise onto the cable it is likely to cause problems. Although your tests may include one for noise, it needs to be quantifiable not arbitrary. My advice would be to contact a network installation company and ask them to design suitable tests or alternatively buy an off-the-shelf stress tester. Pat. Pending

But now where would be the learning and fun in that? Heh, I agree though, if I run into issues with the testing device, that's likely the choices I'll be left with. But, hopefully I'll be able to coin a new easy to build testing device and share with the online community.

Have you looked in to using software based load-testers as part of your testing process? There are a number of freeware applications knocking about. Pat. Pending

. Assuming that breaking just the orange wire will kill the connection (I dunno), all you need is a momentary-contact, single-pole-double-throw (SPDT) switch. Wire it to the NC contacts. To get timer functions, I'd find a 555 timer circuit that has a relay output. You can find timer circuits as complicated or as simple as you need. Searching for 555 +relay should find what you want.
. For the dimmer, a potentiometer should work. No idea what R and W specs would be.

Hey Nacho, on the 555 timer, studying a few of the sites its listed on, (very few), it looks like it simply sends a pulse of electricity at timed intervals. Could you dip in a little more in detail on how it may help.

Again, I just need to create an on/off type switching that throws my orange wire back into play after a set number of seconds.

Here is one site I found with a little info

. Been too long since I did any of this to be of much help with the details. :( IIRC, you want to use the output of the 555 to turn a transistor on/off. The xistor drives the relay.
. The sw at Maplin's is exactly what I was talking about.
.
. I think Pat Pending is making a very good point - ie, a professional job calls for professional tools. What we have been discussing would be OK (but still not great) for a home or non-critical business application, but it won't provide what you need for a "real" network.

. That should work, also. It is an "industrial" grade unit that will probably be more expensive. Plus it will require a socket/base (unless you are going to _really_ jury-rig this project). Since it doesn't auto-reset, the wiring will be a little more complex (not that big of a deal if you can figure out a network). . The unit at Maplin's looks like a better solution to me. . Still think it would be worthwhile to invest in the proper tools.

Awesome, thanks Nacho, I am pulling the part info on those today, and I'll get back to you with an update. Thanks again!

I am curious, what is the purpose of the dimmer? If you are dealing with very low power, you may need to get something on the low end (I had a pot. that had 100 "steps" in it, from .01 ohms up to 10 ohms resistance, but that was a pricey item).

It's to test the low end power loss if any on our system lines. My company has been having intermittent issues lately with network disconnects, and we have no way of tracing their source. They are about to drop $35K on a monitoring/alarm system, and we are in the testing phase now. As the engineer, I have to find a way to create many different types of outages to test the new system. As of now, there are no devices made to create such a test, so I am left designing something myself. Like I said earlier, the closest thing I found was some type of Lag Switch that gamers use to start/stop their connection. But that just doesn't have enough options. Thanks for helping on this guys.

Well, my only thought on the dimmer end is whether you want it to "ring" or not. They use (a) triac(s) in AC dimmers in an attempt to eliminate ringing (I am still sensitive to the dimmer in the old apt. I live in, as we turn it down, I can "hear" the bulbs "ring"). I am not sure that would even be a problem or if it might be something you would want (if it occurred at all).

Hmm, good point, and I am not sure as to what the affect "ringing" would cause on network traffic. I am simply looking to lower the amount of data, or voltage that travels through that line, which is what made me think of a dimmer type switch. I suppose that any added noise on the line would likely cause an issue.

I am just not sure how you would power a triac circuit in the event you wanted use it, as it would have to be completely isolated for testing purposes.