# External ringer for VOIP phone

#### Somethingrandom

Jan 20, 2014
22
Hi All

Can I get a brief overview of what would be required to build an external ringer for a VOIP handset. The scenario is that we have a phone in a commercial kitchen which does not ring loud enough to be heard over the general kitchen noise.

The vendor advises that there is external amplified ringer that I can install inline with the handset as you used to be able to do with PSTN phones.

What would be the easiest way to achieve a boost in volume to the ringer, I am considering some type of external speaker, or somehow boosting the volume of the existing internal speaker.

This is the phone we have.

Thanks

#### Somethingrandom

Jan 20, 2014
22
Hi Davenn, great idea, I didn't think of this, my concern here is that it may amplify random noise not just the phone when it rings. What I was hoping for was a relatively simple method to detect when the ringtone is actively ringing as opposed to active while being used as speakerphone. As long as I can detect this I should be able to rig a suitable buzzer. Perhaps some type of 555 timer circuit would be appropriate here? I'm not entirely sure.

#### Old Steve

Jul 23, 2015
734
What I was hoping for was a relatively simple method to detect when the ringtone is actively ringing as opposed to active while being used as speakerphone.
That makes it tricky. It used to be relatively easy with a landline, because the ring voltage direct from the phone line was AC.
It sounds like the vendor's external ringer might be the way to go. If it's not loud enough, then you could more easily attach an amp or whatever.

#### davenn

Moderator
Sep 5, 2009
14,042
Hi Davenn, great idea, I didn't think of this, my concern here is that it may amplify random noise not just the phone when it rings. What I was hoping for was a relatively simple method to detect when the ringtone is actively ringing as opposed to active while being used as speakerphone. As long as I can detect this I should be able to rig a suitable buzzer. Perhaps some type of 555 timer circuit would be appropriate here? I'm not entirely sure.

There is NO ringtone to the phone ... its all digital in the cable to the phone

for the mic system, a small electric condenser mic enclosed and it could be placed in a way that it really only receives
audio from the ringer speaker

the only other choice is the style I gave ... there are several brands available on the net
most of them plug into another Ethernet port on the server patch panel and the phone system controller is programmed to ring the phone as well as the external ringer on the 2 different IP ports

Dave

Jan 20, 2014
22
Correct the vendor solution is a completely seperate device which plugs into the network and requires wall mounting. It costs $700 and would require wall or ceiling mounting and new cable run to be installed. Not really an option. Condenser mic idea sounds great but it would need to be manually turned off when using speakerphone and I can see people forgetting to turn it back on again when they are done. To be honest I'm not even sure they use the speakerphone so this could actually be a viable option, I will need to find out. But would it be possible to detect some kind of ring signal from the speaker itself for a more eloquent solution? #### Somethingrandom Jan 20, 2014 22 If it's not loud enough, then you could more easily attach an amp or whatever. So the amp would go between the speaker and the circuit board and this would work? I assume it would require external power? What sort of amp could I use? #### davenn Moderator Sep 5, 2009 14,042 So the amp would go between the speaker and the circuit board and this would work? I assume it would require external power? What sort of amp could I use? this would require opening up the phone and connecting into the speaker line BUT, then you would have the exact same possible problem you spoke of in your previous post if the speaker phone mode was used .... Correct the vendor solution is a completely separate device which plugs into the network and requires wall mounting. It costs$700

that one I linked to was \$400 odd but still expensive for something that should be easy
well with the old analog system it was very easy

#### Old Steve

Jul 23, 2015
734
So the amp would go between the speaker and the circuit board and this would work? I assume it would require external power? What sort of amp could I use?
For some reason I didn't get an email notification of your replies.

I was talking about buying the vendor solution to do this, and modifying it. Now that I've seen the cost, that's definitely out.

Overall, you won't be able to do much better than Dave's solutions. It would be very hard, if not impossible, to have a remote ringer that can distinguish between a ring tone and speakerphone usage and only ring with ringtones. Might be possible using a tone detector and other circuitry, depending on the ring tone, but I'm sure you'd still get lots of false triggering. The amplifier itself is the least of your worries. It could be made using very few components + a speaker, or one could be bought ready-made. Any small audio amp would work. The detection is the problem.

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