Switching on a PC over the telephone line

Sun Sep 11, 2011 1:03 am   

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

Sun Sep 11, 2011 1:03 am   

nikos wrote:


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: http://www.ozitronics.com/remote.html#k140




--
You can't have a sense of humor, if you have no sense.

Sun Sep 11, 2011 1:03 am   

On Sat, 10 Sep 2011 19:21:38 -0400, "Michael A. Terrell"
<mike.terrell_at_earthlink.net> wrote:


code pairs. I think I still have a couple of those around.
Does a modern cell phone respect DTMF anymore?

Tom

Sun Sep 11, 2011 1:03 am   

Tom Biasi wrote:


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.


--
You can't have a sense of humor, if you have no sense.

Sun Sep 11, 2011 4:12 am   

On Sat, 10 Sep 2011 16:03:02 -0700, nikos wrote:


Wake-On-LAN. Or a modem.

Sun Sep 11, 2011 5:28 am   

On 2011-09-10, nikos <niioannou_at_gmail.com> wrote:

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.

http://en.wikipedia.org/wiki/Power_distribution_unit

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

http://en.wikipedia.org/wiki/Wake-on-lan

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.

Sun Sep 11, 2011 6:02 am   

On Sat, 10 Sep 2011 19:32:29 -0400, Tom Biasi wrote:


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?

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Sun Sep 11, 2011 9:12 am   

On 2011-09-10, nikos <niioannou_at_gmail.com> wrote:

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?

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news_at_netfront.net ---

Sun Sep 11, 2011 9:15 am   

On 2011-09-10, Tom Biasi <tombiasi_at_optonline.net> wrote:

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

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news_at_netfront.net ---

Mon Sep 12, 2011 11:51 am   

On Sun, 11 Sep 2011 01:02:34 -0500, Tim <tim_at_seemywebsite.please>
wrote:


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

Tue Sep 13, 2011 7:54 pm   

nikos wrote:


You can get a pulse Relay online from various sources or if you want
something very basic.. You can do this.





(N)
+
|
| \
+ o o
+--------------------------------+ 120VAC )|
| | )|
| | +)|
| ___ + |
+---+-----+>|+----+|___|-+-------+_ o +------------+
| )| NC contact
| 12VDC )|
+ _)|
120 AC --- +
--- |
+ |
| |
| |
(N)+---+--------------------+--------+
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

The contacts on the 120VAC relay can be used to connect to your PC switch.

When energized, 120 Relay will pull in and when the 12DC relay
gets enough to close, it'll open its NC contacts and thus open
the 120VAC relay. This will give you a pulse.

THat is a very crude circuit and the load of the DC coil is a need to
know for the proper R to get correct dropping voltage. When this is
known, you then can select your cap to determine the delay on state.
The diode being just what ever you have around that can handle the line
voltage and at least 1 amp.

Of course, most of us here would use something a little more detailed
how ever, this one will allow you to use power that is commonly available.


Jamie

Tue Sep 13, 2011 8:40 pm   

nikos wrote:

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.

Tue Sep 13, 2011 9:02 pm   

On Sep 11, 12:15 pm, Jasen Betts <ja...@xnet.co.nz> wrote:

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

Tue Sep 13, 2011 9:26 pm   

nikos wrote:


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


--
You can't have a sense of humor, if you have no sense.

Wed Sep 14, 2011 11:52 am   

On Tue, 13 Sep 2011 12:02:54 -0700 (PDT), nikos
<niioannou_at_gmail.com> wrote:


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