Searching \ for '[EE]: Telephone gyrator' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/pots/dtmf.htm?key=telephone
Search entire site for: 'Telephone gyrator'.

Exact match. Not showing close matches.
PICList Thread
'[EE]: Telephone gyrator'
2001\07\05@041345 by Jeszs

flavicon
face

Hi everyone!

Months ago I built a home alarm to call my mobile upon intruder detection.

Main parts:
- 16PIC84
- MT8880: DTMF recognition and generation
- 600 Ohm transformer to interface the phone line

I had many difficulties to engage the line and send tones through it but finally I found the concept 'gyrator' and built one as per a web page recommendations.

Today, summer in Spain, the machine is failing. Sometimes it works ok and sometimes my phone company operator says the dialled number is not correct.

Do you know a 'standard' way to attach the line to the transformer and the transformer to the MT8880?

Thank you very much in advance!


--------------------
Jesús Gonzalo
INSA, Ingeniería y Servicios Aeroespaciales, SA
Paseo Pintor Rosales 34
Tel: +34-915489149
28008 Madrid (SPAIN)
--------------------

2001\07\05@110745 by Dan Michaels

flavicon
face
Jesús Gonzalo wrote:
........
>
>Do you know a 'standard' way to attach the line to the transformer and the
transformer to the MT8880?
>

I have links to telephone circuit info here:

http://www.oricomtech.com/teklink2.htm

--
http://www.piclist.com hint: To leave the PICList
spam_OUTpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu


2001\07\05@225955 by Patrik Husfloen

picon face
I have one of those, well, I got it from a friend who used to work at a big alarm/security company, it has an eeprom which stores 9 numbers which it calls in sequence, and then it "beeps" this special sequence, optionally you can have it send a pre-recorded msg to each phone number.
it's programmable from any phone, ie you hook it up to the line, and use your phone to program it with DTMF..
I never used it, I have manuals and everything for it, it looks rather simple


{Original Message removed}

2001\07\06@034018 by zantos

flavicon
face
Found this very useful

http://www4.tpg.com.au/users/talking/DialAlarm-1-Page1.html

----- Original Message -----
From: "Patrik Husfloen" <.....u58611234KILLspamspam@spam@TELIA.COM>
To: <PICLISTspamKILLspamMITVMA.MIT.EDU>
Sent: 06 July 2001 04:01
Subject: Re: [EE]: Telephone gyrator


> I have one of those, well, I got it from a friend who used to work at a
big alarm/security company, it has an eeprom which stores 9 numbers which it
calls in sequence, and then it "beeps" this special sequence, optionally you
can have it send a pre-recorded msg to each phone number.
> it's programmable from any phone, ie you hook it up to the line, and use
your phone to program it with DTMF..
> I never used it, I have manuals and everything for it, it looks rather
simple
{Quote hidden}

detection.
> >
> > Main parts:
> > - 16PIC84
> > - MT8880: DTMF recognition and generation
> > - 600 Ohm transformer to interface the phone line
> >
> > I had many difficulties to engage the line and send tones through it but
finally I found the concept 'gyrator' and built one as per a web page
recommendations.
> >
> > Today, summer in Spain, the machine is failing. Sometimes it works ok
and sometimes my phone company operator says the dialled number is not
correct.
> >
> > Do you know a 'standard' way to attach the line to the transformer and
the transformer to the MT8880?
{Quote hidden}

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2001\07\07@133905 by Alejandro

picon face
Hola Jesús!

Bueno, supongo que andas necesitando lo que en telefonia se llama
una "hibrida", que transforma un canal de 2 hilos en dos canales de
2 hilos, uno para enviar y otro para recibir.
Los viejos-viejos telefonos tenian un transformador especial que cumplia esa
funcion,
a ese trafo se lo llamaba "hibrida". Tambien existen circuitos basados
en resistencias que cumplen la misma funcion (pero introduciendo
atenuacion),
y mas modernamente se usa un par de operacionales (para eliminar la
atenuacion). Tecnicamente el circuito se comporta como un "circulador",
esto es, un hexapolo que transmite energia en un sentido desde
un par de bornes al par de bornes adyacente.
A lo mejor te ayuda destripar algun telefono y fijarte como es...

Saludos de
           Alejandro.

{Original Message removed}

More... (looser matching)
- Last day of these posts
- In 2001 , 2002 only
- Today
- New search...