Help with a speaker related electronics conundrum
Discussion
One for the few audio electronics specialists here.
I have a door intercom that has a connection on it for an extension chime (two wires). I would like to put chime extensions in many more rooms though (say 6). Unfortunately this extension connection isn't just a dry contact relay, it's active. When the call button is pressed on the intercom I measure 3V at this extension output that then slowly drops to a few hundred millivolts over about the 15 seconds subsequent to the button push.
Can I simply amplify this and use it to drive a multi speaker system or could it be some kind of control voltage? I've ordered the official extension chime which will get here in a week or so and I'll take to to bits and multimeter the hell out of it but in the meantime, any ideas?
I have a door intercom that has a connection on it for an extension chime (two wires). I would like to put chime extensions in many more rooms though (say 6). Unfortunately this extension connection isn't just a dry contact relay, it's active. When the call button is pressed on the intercom I measure 3V at this extension output that then slowly drops to a few hundred millivolts over about the 15 seconds subsequent to the button push.
Can I simply amplify this and use it to drive a multi speaker system or could it be some kind of control voltage? I've ordered the official extension chime which will get here in a week or so and I'll take to to bits and multimeter the hell out of it but in the meantime, any ideas?
Driller said:
One for the few audio electronics specialists here.
I have a door intercom that has a connection on it for an extension chime (two wires). I would like to put chime extensions in many more rooms though (say 6). Unfortunately this extension connection isn't just a dry contact relay, it's active. When the call button is pressed on the intercom I measure 3V at this extension output that then slowly drops to a few hundred millivolts over about the 15 seconds subsequent to the button push.
Can I simply amplify this and use it to drive a multi speaker system or could it be some kind of control voltage? I've ordered the official extension chime which will get here in a week or so and I'll take to to bits and multimeter the hell out of it but in the meantime, any ideas?
It could be some form of trigger voltage. What kind of meter were you measuring with? was it a true RMS meter ?? 3V AC very high for line level ( a CD player gives out 2.0v and many power amps give full output when fed by only 1.0v ).I have a door intercom that has a connection on it for an extension chime (two wires). I would like to put chime extensions in many more rooms though (say 6). Unfortunately this extension connection isn't just a dry contact relay, it's active. When the call button is pressed on the intercom I measure 3V at this extension output that then slowly drops to a few hundred millivolts over about the 15 seconds subsequent to the button push.
Can I simply amplify this and use it to drive a multi speaker system or could it be some kind of control voltage? I've ordered the official extension chime which will get here in a week or so and I'll take to to bits and multimeter the hell out of it but in the meantime, any ideas?
Its possible that the extension output is designed to drive a speaker directly; have you traced the board back from the relay ? Remember 2.83vac is 1w into an 8 ohm load........1w will be loud enough for an efficient little mylar type sounder work as a chime in a pretty large room. If you need to do several rooms then you need to take care about how you series / parallel the connections back at the door intercom end to make sure the intercom doesn't 'see' a difficult load.
Crackie said:
It could be some form of trigger voltage. What kind of meter were you measuring with? was it a true RMS meter ?? 3V AC very high for line level ( a CD player gives out 2.0v and many power amps give full output when fed by only 1.0v ).
Its possible that the extension output is designed to drive a speaker directly; have you traced the board back from the relay ? Remember 2.83vac is 1w into an 8 ohm load........1w will be loud enough for an efficient little mylar type sounder work as a chime in a pretty large room. If you need to do several rooms then you need to take care about how you series / parallel the connections back at the door intercom end to make sure the intercom doesn't 'see' a difficult load.
Hi Crackie, I was hoping you’d be along. That’s a lot of great info, thank you. My meter is a very bog standard one I think and I have no idea whether it’s true RMS or not. I shall post a pic up of it.Its possible that the extension output is designed to drive a speaker directly; have you traced the board back from the relay ? Remember 2.83vac is 1w into an 8 ohm load........1w will be loud enough for an efficient little mylar type sounder work as a chime in a pretty large room. If you need to do several rooms then you need to take care about how you series / parallel the connections back at the door intercom end to make sure the intercom doesn't 'see' a difficult load.
It makes sense that that could be enough to drive a small speaker because the extension chime is passive as far as I know.
I’ll receive it at the end of the week and will pull it to pieces and post up the results.
If it is just a speaker then, as you suggest, I imagine the others would have to be put together in a combination of series and parallel to maintain the correct resistance. A bit like the Celestions in a 4x12 cab?
Driller said:
I had it on DC 20. when I measured it.
Ah.....that doesn't sound good. If it was an output for driving a speaker then there should be zero volts DC on the output. A speaker needs an AC voltage to drive it........a DC voltage would just push ( or pull ) the coil out of the magnetic gap and then heat it up.Try and measure the output with the meter on AC and see what you get.
If you did have a big 12" pro speaker driver then it will cope with 3v DC for a little while. Connecting one briefly ( just touch the terminals ) would tell you what you need to know without a meter; just take care to observe the speaker cone does when you make contact. If you see any in or out cone movement away from the centre position then there is DC present.
Edited by Crackie on Sunday 7th January 22:51
They are usually just a dry or extra low voltage as a trigger then a rest of the circuit with play a the preprogrammed chime.
You could get a little relay to remove the voltage, but then what are you going to use as a signal out to the new chain of speakers?
Is a chime or bell system, because a bell is just a 12v or 9v circuirt being completed, very very basic.
V.
You could get a little relay to remove the voltage, but then what are you going to use as a signal out to the new chain of speakers?
Is a chime or bell system, because a bell is just a 12v or 9v circuirt being completed, very very basic.
V.
Hi Vex, thanks for joining in.
Some more info for Crackie and you, I just remeasured the votage on an AC setting on the meter.
The ringer is a Ding, Dong type affair and when the button is pressed, on the Ding I measure 2.5VAC which then drops quickly to close to zero before the Dong then brings it back up to 2.5VAC and back down to zero again.
Extension speaker should be here in a few days.
Some more info for Crackie and you, I just remeasured the votage on an AC setting on the meter.
The ringer is a Ding, Dong type affair and when the button is pressed, on the Ding I measure 2.5VAC which then drops quickly to close to zero before the Dong then brings it back up to 2.5VAC and back down to zero again.
Extension speaker should be here in a few days.
Edited by Driller on Tuesday 9th January 12:05
I have no experience working with alarms so VEX's experience / knowledge will be good to have on this one.
Having thought about my previous post a little more; if you were to series parallel 4 sounders, from different rooms, back to to the alarm unit its quite possible that there would be relatively little power reaching each sounder ( due to a combination of series parallel connection and voltage drop in the wire.
What do you think VEX ?
Having thought about my previous post a little more; if you were to series parallel 4 sounders, from different rooms, back to to the alarm unit its quite possible that there would be relatively little power reaching each sounder ( due to a combination of series parallel connection and voltage drop in the wire.
What do you think VEX ?
D.
Does the ring go 'Ding' as you push and hold the call button and 'Dong' when you let go or 'Ding / Dong' as soon as you push it?
I have a feeling there could be a more electronics in the handset / internal module that generates the 'call notification'
In the older style entry panels pass either 9/12v through a contact closure and that just drove a mechanical bell / chime.
Who is the manufacturer of the entry panel? maybe we can research it from that direction.
V.
Does the ring go 'Ding' as you push and hold the call button and 'Dong' when you let go or 'Ding / Dong' as soon as you push it?
I have a feeling there could be a more electronics in the handset / internal module that generates the 'call notification'
In the older style entry panels pass either 9/12v through a contact closure and that just drove a mechanical bell / chime.
Who is the manufacturer of the entry panel? maybe we can research it from that direction.
V.
Ok, so there is some electonics in the ringer bit itself that reponds to the button push to create the dingdong
So, the difficulty you have is that the 'external trigger' that you are measuring off propably doesnt generate a dingdong, so whilst you could use it to trigger in indication that someone is at the door, either directly or using a little relay to stip off the 2.5/3v, you then need to go into something else to create the noise.
You could buy a cheep wireless doorbell and extensions and (as I have just done with my demo doorbird internet doorbell install) wire the existing trigger outs across the button push of the wireless outdoor button. Then hide it behind the entry panel etc.
Then you have notification where ever you put the ringers.
I did this because sometime the phones are on silent when we are home, so we needed to know if someone was at the door.
V.
So, the difficulty you have is that the 'external trigger' that you are measuring off propably doesnt generate a dingdong, so whilst you could use it to trigger in indication that someone is at the door, either directly or using a little relay to stip off the 2.5/3v, you then need to go into something else to create the noise.
You could buy a cheep wireless doorbell and extensions and (as I have just done with my demo doorbird internet doorbell install) wire the existing trigger outs across the button push of the wireless outdoor button. Then hide it behind the entry panel etc.
Then you have notification where ever you put the ringers.
I did this because sometime the phones are on silent when we are home, so we needed to know if someone was at the door.
V.
Vex you clearly know your stuff and I thought you were just a Multiroom guy 
If I understand correctly are you suggesting using the existing push button in the door station to make a circuit on another bell system, 12V or 24V? Is that voltage not going to mess with the door station?
ETA Ah ok after rereading I see you said “trigger outs”. So you mean add a relay that can be closed by 2.5 V to trigger in turn another chime system?
BTW forgot to say, it’s an Aiphone DB series with a master and 4 substations inside.
BUT! You mentioned DoorBird. Would you believe that amongst all the other things I’m playing with on the dining room table I have a D2102V?
It’s a lovely bit of kit and without breaking the seal on the admin pack I’ve been trying to work out how to use it intead of the Aiphone. The idea would be to hook it up to the IP phone based interior paging system I’m setting up. If I can’t get it to do what’s needed I’ll send it back hence not breaking the seal but it’s a bit tricky to experiment without the admin password.
This is the other option than reusing the Aiphone and putting chime extension in.
Apparently it’s ONVIF so NVR recording won’t be a problem but I need to get it to register with the IP PBX I got with the IP phones so that it can be configured to call a ring group. It would appear that it calls to an IP address rather than an extension so I’m going to have to set it up in the pbx as a Peer Sip Trunk.
Anyway it looks like a fantastic bit of kit, have you been working with them a while?
If I understand correctly are you suggesting using the existing push button in the door station to make a circuit on another bell system, 12V or 24V? Is that voltage not going to mess with the door station?
ETA Ah ok after rereading I see you said “trigger outs”. So you mean add a relay that can be closed by 2.5 V to trigger in turn another chime system?
BTW forgot to say, it’s an Aiphone DB series with a master and 4 substations inside.
BUT! You mentioned DoorBird. Would you believe that amongst all the other things I’m playing with on the dining room table I have a D2102V?
It’s a lovely bit of kit and without breaking the seal on the admin pack I’ve been trying to work out how to use it intead of the Aiphone. The idea would be to hook it up to the IP phone based interior paging system I’m setting up. If I can’t get it to do what’s needed I’ll send it back hence not breaking the seal but it’s a bit tricky to experiment without the admin password.
This is the other option than reusing the Aiphone and putting chime extension in.
Apparently it’s ONVIF so NVR recording won’t be a problem but I need to get it to register with the IP PBX I got with the IP phones so that it can be configured to call a ring group. It would appear that it calls to an IP address rather than an extension so I’m going to have to set it up in the pbx as a Peer Sip Trunk.
Anyway it looks like a fantastic bit of kit, have you been working with them a while?
Edited by Driller on Wednesday 10th January 14:29
Edited by Driller on Wednesday 10th January 14:30
And here’s a pic inside. I forgot to say there’s a sliding volume control (which can be seen in the radiograph) and on a PCB next to this is a capacitor of some sort (below the sliding switch, next to the wires) and a small resistor (just above the switch).
The PCB is turned upside down in the enclosure and held in place by a cross head screw (seen just below and right of switch in radiograph) so the components can’t be seen. The head of this screw is filled with resin. If necessary I can take this screw out to see the PCB directly but I think we can see enough and it might be a pain to get the resin out.
Does this help?
The PCB is turned upside down in the enclosure and held in place by a cross head screw (seen just below and right of switch in radiograph) so the components can’t be seen. The head of this screw is filled with resin. If necessary I can take this screw out to see the PCB directly but I think we can see enough and it might be a pain to get the resin out.
Does this help?
Reading up it would seem that the capacitor acts as a high pass filter for the lower volumes on the volume control.
So it would appear that this thing is nothing but a passive extension speaker.
That being the case I could just amplify the signal and distribute it around the other rooms. What’s the best way to do this?
So it would appear that this thing is nothing but a passive extension speaker.
That being the case I could just amplify the signal and distribute it around the other rooms. What’s the best way to do this?
If the signal is an audio one (and not a trigger) then I'd consider a circuit like this:
chime -------C-------R1-----------Signal amp input
.........................................|
.........................................|
........................................R2
.........................................|
.........................................|
chime--------C-------R1----------Gnd amp input
The voltage out of the chime may be a bit high for an amp input.
Also with the DC level apparently present and who knows what ground connections I'd be inclined to capacitively couple both connections.
Cs are, say, 1uF 25V (or higher). R1s are 1k R2 is whatever you can get between 560-680R.
Peer review chaps?
[footnote]Edited by jet_noise on Saturday 13th January 13:45
Ignore the dots, needed to make ASCII circuit look right, forum formatting ignores multiple spaces!
[/footnote]
chime -------C-------R1-----------Signal amp input
.........................................|
.........................................|
........................................R2
.........................................|
.........................................|
chime--------C-------R1----------Gnd amp input
The voltage out of the chime may be a bit high for an amp input.
Also with the DC level apparently present and who knows what ground connections I'd be inclined to capacitively couple both connections.
Cs are, say, 1uF 25V (or higher). R1s are 1k R2 is whatever you can get between 560-680R.
Peer review chaps?
[footnote]Edited by jet_noise on Saturday 13th January 13:45
Ignore the dots, needed to make ASCII circuit look right, forum formatting ignores multiple spaces!
[/footnote]
Edited by jet_noise on Saturday 13th January 13:46
Appreciate you getting involved Jet_Noise, you clearly know your stuff!
Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Edited by Driller on Saturday 13th January 20:25
Edited by Driller on Saturday 13th January 20:37
Driller said:
Appreciate you getting involved Jet_Noise, you clearly know your stuff!
Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Edited by Driller on Saturday 13th January 20:25
Edited by Driller on Saturday 13th January 20:37
Does every home have at least one unused spare set of cheap PC speakers in the cupboard/loft/wardrobe?
No great loss if they went west.
Driller said:
Appreciate you getting involved Jet_Noise, you clearly know your stuff!
Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Cool, so the thing we all missed is that the voltage you have measured actually has a frequency component to it to generate the two tone Ding/Dong. Although 2.5v is a little high to drive into your active speakers which should be rated at 1v Peak to Peak. (If my 25year old Uni Electronics serves me right)Since I discovered that the “official” extension speaker is just a...speaker, I found the time just now to connect the output of the master station to an amplifier PC speaker.
It worked like a charm, so we’re in business!
Edited by Driller on Saturday 13th January 20:25
Edited by Driller on Saturday 13th January 20:37
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