Line Powered Corded Phone - again

Why would the off hook signal from the telco not be sufficient noise?

"Lord Garth"

** Nope.

That can only be heard from less than 1 metre even in a very quiet room.

..... Phil

It's obviously not sufficient for my mother to hear it.

Dave.

What makes you think any other phone would have a louder off hook signal though? I'm amazed the phones they supply for the hearing impaired don't even have a decent ring volume, unless you also pay for an extension bell. That's what happens when the government mandates something for the disabled, without actually knowing (or caring) what is really needed.

MrT.

I can here my bedroom phone in my kitchen some 20 feet away. Seems the cat kicked the phone off hook. The receiver was aimed upwards however.

Ah! Mine is 84 and has a similar problem.

Off on a tangent would any one have a circuit or way to fit a strobe light on phone for deaf people (like those blue lights on house alarms)

A phone left off hook after a call makes very little noise unless the exchange sends a warning which some have but I dont think all do.

Even Dial Tone is not loud enough to attract attention.

John G.

In the UK they used to have a 'howler', where if a phone was left off the hook the operator could sreate a howl and increase it in volume until there was a response from the subscriber. In Aust now you get a short period of alteranate loud and soft beats and then the phone is disconnected automatically, although it can be reconnected by clearing down and then starting again.

now

o

I think you will have to "roll your own".

there have been various "off hook indicator" circuits published over the years. here is the first one I found that

Vaguely remember SC did one in recent years that might be approved too as a bonus.

here is another that seems to specialise in ready built units - that are also likely to be approved

No prices though.

Since they dare to mention the use of incandescent lamps, the "Green bulb Gestapo" might put them out of business, so better grab one while you can ;)

I have never heard of that feature on any consumer phone.

Another alternative is to possibly have the phone wall mounted, and get one that the handset wont sit anywhere unless its properly hung up

"Lord Garth"

** Then you obviously do not live in Australia.

What planet is it that you do ?

** Musta thought that purring noise was some extra-terrestrial feline trying to make contact ......

..... Phil

I'm thinking perhaps there is a phone out there that has its own off-hook beeper or something. Many have an off-hook visual indicator.

Dave.

I just plugged in an old Optus phone I found, and I could barely hear it half a meter away in a very quiet room. Also, the off-hook signal only goes for about a minute and then switches off to just an even quieter static. Do others get the same thing?

Dave.

Yes that's the standard action from exchanges like Ericcson and the like. Prevents tying up exchange equipment. Used to be called 'permanent glow' and was the bugbear of systems running in 1900 or so! That's one of the reasons why switchboards were centrally mounted with milliameters, to keep an eye on the PG status.

On Wed, 25 Feb 2009 07:09:47 +1000, "David L. Jones" put finger to keyboard and composed:

You wouldn't want a beeper going off when you are talking or dialling, so the phone would need to be able to distinguish between a conversation and an accidental off-hook condition, and it would need to be able to recognise a dialtone. If the phone were to base its off-hook detection on line current and an absence of sound, then any background noise such as the TV could defeat it. Therefore it seems to me that an audible warning would be difficult to implement. However, one possible way of implementing such a feature might be to sense whether or not the handset is being held in a person's hand, but this may run into isolation problems in the case of a line powered phone. You would also have the beeper going off if you put the phone down in the middle of a conversation, although in this case the phone could automatically go on-hold.

- Franc Zabkar

--
Please remove one \'i\' from my address when replying by email.

Hi Dave,

I'm in Dallas Texas. I have a Panasonic corded desk phone. Yes, the telco switch will kill the circuit after some time.

I suppose I should tell you that I have exceptional high frequency hearing. Though I haven't been tested recently, at age 28, I was hearing far higher than average. Seems my ear drums are both larger than average and tight. The down shot is that loud is painful to me.

I probably should go get tested again to see how time has altered my range.

Where do you live? What phone do you have? Does it switch off after a minute or two?

Dave.

A beeper with a fairly long quiet space like a houshold fire alarm "flat battery" beeper might work as it would eventually alert the user. I was about to build such a thing for a blind person a few years ago but he died and I dropped the project. John G.

Sure, and that's usually enough. I can't recall ever seeing a phone with it's own off hook beeper though, or anybody else that wants one for that matter.

MrT.