Dialer problem with a picchip

Fooled me too !

Graham

OK, you say so...

Ok which one? I bought two books and none of them go technical about the frequencies of dial tone and busy signal, and not even close to giving out out the on /off hook voltage. which I found out another way ' On Hook: 40 to 50 VDC ' Off Hook: 4 to 6 VDC ' Ringing: 100 VAC

I will keep using jpg, Gif can be animated which could be a potential source of virus (which can prevent from people wanting to view the file) and yes I have seen gif with virus .

al level. Try

From the spec sheet it says voltage between 2.5 and 5.5 v, therefore I thought the output of a pic would be suitable. from the circuits they dont seem to go that low, but its worth to try, thanks

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K

Typical for a "modern" office in the US and probably Canada, is a set of signals called "Precise to signals:

Dial Tone: 350 Hz + 440 Hz, nominal maximum deviation +- 0.7% per frequency.

Line Busy tone: 480 Hz + 620 Hz, nominal maximum deviation +- 1.5% per frequency. Timing is 60 ipm, 0.5 sec on, 0.5 sec off, 10% tolerance on all parameters.

Audible ringing tone: 440 Hz + 480 Hz, nominal maximum deviation +- 1.6% per frequency.

Nominal On Hook voltage will be 52V.

Off hook voltage should never be less than about 6.6V, and it can be considerably higher depending on the Telco serving arrangement including the length of their cable pair. The DC circuit path provided by the "telephone device" may have a resistance of 200 or 330 Ohms. The lower value may be used by devices using DP signaling, and 330 Ohms may be used for tone signaling devices. If your tone signaling device doesn't use Network loop current, I suppose the DC path of your devise can be anywhere between the two.

The most common ring signal is 20 Hz, +- 3 Hz with an AC magnitude (at the NI) of 30 to 106 V rms superimposed on a DC voltage of less than 80 V. Newest ring generators spec at 20 Hz +- 1 Hz.

If you are designing a product for use by others, you need to assure it conforms with the Federal Code of Regulations 47, Part 68, and that it gets Registered.

All the technical insight you require is available there.

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Would this voltage be on the receiving end ( for the 20Hz and 30 to

106 v) ? if so then I am mostly concerned with the sending end, which I have read so far receives a dual frequency, just as in the DTMF generation. I have been reading up on call progress chip at Decoding could be done with DSP onto a Pic chip, Maybe JeffM would have such an algorithm ?

Ken

Yes. At the Network Interface at the customer premises being called.

From my original reply: Audible ringing tone:  440 Hz + 480 Hz, nominal maximum deviation +- 1.6% per frequency.

This is the signal you hear after the call is originated, and the phone at the other end is ringing.

Teleph>Typical for a "modern" office in the US and probably Canada, is[...]

While all of that is needed for the project, his initial problem is even more fundamental.

On-Hook and Off-Hook are NOT *voltage* specifications.

You may find those numbers useful, but they are NOT the spec.

To repeat: On-hook and Off-hook are NOT *voltage* specifications. (Think about the long lines of varying lengths that go to subscribers.)

*-mA

You are a selfish dumb-ass.

Just silly; ANY file can be infected.[1] If you're nervous about GIF, capture in PNG. JPEG is stupid for this. It gives lousy results visually and makes unnecessarily large files. . . [1] If the morons in Redmond would seperate *data* from *code*, this wouldn't be an issue.

well.http://www.google.com/images?q=hybrid-transformer

jpegs are no safer than gifs there have been exploits in faulty software for displaying both, both standards ar 20 years old and i think all sofware used these days is safe.

neither gif nor jpeg by design can contain live executable code

Bye. Jasen

level. > Try

Link please ?

WHAT SPEC SHEET ? Are you an IMBECILE ?

I told you where to get the DTMF specs and you clearly you didn't bother.You're a classic example of trying to run before you can walk.

Look at the voltage outputs on this old DTMF dialler chip !

We're talking several hundred MILLIVOLTS not bloody 5V pk-pk.

Graham

Why ?

It's all on the net ! Don't you know how to use Google ?

Graham

I wonder if he even knows V=IR !

Graham

On Tue, 2 Sep 2008 19:43:30 -0700 (PDT), JeffM wrote: