Switching on a PC over the telephone line

I am trying to find a circuit that I will be able to switch on my PC that is 200 klm away (like pressing the switch toggle button remotely). Does anybody has an idea ?

Thank you in advance

Nikos

Reply to
nikos
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A dial in DTMF decoder, with a four or six digit password. These were common about 20 years ago. You dialed the number and the device answers with a beep. Then you type the port number and password on the phone's keypad. It then closes a relay for a half second for that port. The ones we used had eight output ports and were used to select a video feed (Via microwave STL) from a remote site.

Monroe Electronics used to make them, but I didn't see it on their website.

There is a kit availible online, and you can likely find other sources:

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Reply to
Michael A. Terrell

There was a kit called "Sweet Sixteen". It would decode all sixteen code pairs. I think I still have a couple of those around. Does a modern cell phone respect DTMF anymore?

Tom

Reply to
Tom Biasi

I have no clue, since I don't use a cell phone. I have a local service only landline, a 'Magic Jack' & Skype. The first two are DTMF.

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Reply to
Michael A. Terrell

There is commercial hardware for this. E.g. 19" rack mounted power distribution systems with ethernet and serial ports. You can log into these things and turn on and off the power ports. Serial port means you can stick a modem on it set to auto-answer. Dial in and turn it on.

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Also, there are ways to do this over the Internet: ethernet adapter/motherboard with WOL (wake-on-LAN) support.

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To use this, it behooves you have a router with some tool to support this: e.g. Tomato Firmware (which runs on a Linksys WRT54GL and others). In Tomato's web-based firmware application, there is a tool where you can send a wake up packet to any hosts within the LAN by their MAC address.

To log into your router, you, of course, need a static IP address, or else dynamic DNS.

Reply to
Kaz Kylheku

Wake-On-LAN. Or a modem.

Reply to
Nobody

The buttons don't make DTMF when you're dialing, but after you're connected they do. How else would you talk to automated answer systems?

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Reply to
Tim

what sort of internet router do you use, can it be customised, perhaps you can set it up to send a "wake on lan" signal?

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Reply to
Jasen Betts

yes they send them so that users can interact with DTMF controlled services like PABXs, banks, and answerphones.

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Reply to
Jasen Betts

I could speak to it like most of the systems I encounter. Thanks for the info. I figured they don't produce the tones but the digit is encoded at the other end, which would mean the kit wouldn't respond.

Tom

Reply to
Tom Biasi

t.net ---

By the way, following my initial request, I have installed a security system (Paradox SP 7000) that is able to receive dial tones. This security system provides 4 PGMs (Programmable Modules) that are actually 4 relays. Each relay can be controlled through the dial tones over the phone line. The thing is that when I close the relay, it remains closed and I need about 2-3 seconds in order to open it (through the dial tones). If I connect the relay to a PC switch button then the computer switches on and off because the 2-3 seconds duration is long. So I need an extra circuit with maybe a new intermediary relay, between the PGM relay and the PC switch button in order to force it open after 500 millisecs of the activation time. Does anybody have an idea on this ?

Nikos

Reply to
nikos

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Reply to
Jamie

snipped-for-privacy@netfront.net ---

A relay, switched by the controlled relays,put in series, for reliability. The relay should have a capacitor in series with the coil, and a leak resistor across the capacitor. That will take care of the timing, try a few caps with the chosen relay, for a proper timing, 100uf sounds right for a starting value.

Reply to
Sjouke Burry

snipped-for-privacy@netfront.net ---

A simple 555 timer wired as a one shot & a small relay.

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Reply to
Michael A. Terrell

"Back in the day" it was common to use the switch on the plug strip to turn on the computer, monitor, printer, etc all at once. Now, it seems the computer's power button must be pushed. But I wonder if it's possible to make the computer revert to the old ways...something in the BIOS or APM system, possibly? It seems like this would be an easy thing for the manufacturer to have provided; maybe they did?

Best regards,

Bob Masta DAQARTA v6.02 Data AcQuisition And Real-Time Analysis

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Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, FREE Signal Generator Pitch Track, Pitch-to-MIDI Science with your sound card!

Reply to
Bob Masta

Yes, that function (boot on power restore, or similar) is often an option in BIOS.

Reply to
krw

Of course, in the old days the on/off switch actually switched power, so if you left it on in the equipment, it didn't matter whether it was turned on there or from the power strip.

Now, a lot of equipment, computers included, keep a bit of power running through it all the time, and the on/off switch is connected to some active circuitry which then turns on the rest of the power.

And of course, some have pointed out that it is worked around in current computers, but it's through compensation to make up for the change from the old days.

Oddly, it should be easier nowadays to turn on a computer remotely, since one can just short the switch terminals together with some low current device, unlike in the old days when you'd have to turn on a relay that could supply all the current the computer needed.

Michael

Reply to
Michael Black

You are not trying to make a IED, are you? :)

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Reply to
Man-wai Chang

Some years ago, I had an answering machine which, if I pressed a certain number key at some point in the "leave your message" interval, could replay my messages over the phone line to me.

Hacking something like that to do whatever you want to do these days should be almost trivial.

And they've probably got something more sophisticated than cassette tapes! ;-)

Have Fun! Rich

Reply to
Rich Grise

Where are these kids coming from? There's been wake-on-ring for freaking DECADES!!!

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Is it just that modern technology has gone so far out there that you'd have to do computer hacker/technology archaeology to find something that actually accomplishes the same thing as they did back then, as simply as they did back then?

Thanks, Rich

Reply to
Rich Grise

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