Ringing a landline Phone on stage  - Page 1
Forum section: electronics / projects

author: ianscott
author_rank: Contributor
timestamp: February 08, 2015, 03:30:45 am
content: Hey guysI am doing a show where the phone has to be rung from off stage. I am having trouble finding any information on how these land line phones work.The phone i want to ring is a normal Australian Landline phone with a RJ11 connector.Does anyone know the voltages and such to ring a normal land line phone?I have found thishttp://www.tele-q.com/operating.phpwhich is exactly want but I the price is a bit high to ring a phone once or twice a show. Does anyone know how to do this simply and cheaply?Thanks Ian

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 08, 2015, 03:34:08 am
content: I know the US ring signal is about 70 volts, at 20 Hz. I can't imagine the Austarilian phones being very much different.

author: jmole
author_rank: Regular Contributor
timestamp: February 08, 2015, 03:35:36 am
content: A quick search on google netted this:http://www.epanorama.net/circuits/telephone_ringer.html

author: Muttley Snickers
author_rank: Unknown
timestamp: February 08, 2015, 03:48:29 am
content: I have a Ring Master Pro Line Simulator, think I paid around $220.00many years ago from a company in Melbourne, here's a link to themanufacturer in Queensland.http://www.natcomm.com.au/au/telephone-line-simulators/Muttley

author: dfmischler
author_rank: Frequent Contributor
timestamp: February 08, 2015, 03:53:40 am
content: I have had one of these for many years:Viking DLE200B. I originally bought it around 1995 to simulate a phone line between two modems for product development and testing. Has run many thousands of cycles and is still reliable. Mine is slightly different from the pictured version (reset button on front and DIP switches underneath).I see several of these selling on ebay at this time:http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=dle200b&_sop=15

author: Muttley Snickers
author_rank: Unknown
timestamp: February 08, 2015, 03:55:42 am
content: You also may be able to put a mobile phone along side a normalhandset, set the ring tone and ring it with another phone.It's a bit dodgy, but if it all went wrong could be good entertainment.Muttley

author: Unknown
author_rank: Unknown
timestamp: February 08, 2015, 04:04:55 am
content: Australian ring current is typically 16 or 25Hz, max 90-110v AC, with a cadence of 400ms on, 200ms off, 400ms on, 2s off.If you just want it to ring then 18-24v AC should work on a short loop. For realism, the frequency might be critical - the tone of the electronic ringers in T200/T400/etc was much more dependent on the actual ring frequency than the bells or electronic ringers of the earlier 800-series.

author: ianscott
author_rank: Contributor
timestamp: February 08, 2015, 04:09:54 am
content: Quote from: Muttley Snickers on February 08, 2015, 03:55:42 amYeah i did think of that, but the phone has to ring for a while, so manual control it is. Thanks anyway

author: Muttley Snickers
author_rank: Unknown
timestamp: February 08, 2015, 04:14:53 am
content: What state are you in, and how long do you need one for.Muttley

author: ianscott
author_rank: Contributor
timestamp: February 08, 2015, 04:15:52 am
content: Quote from: Tac Eht Xilef on February 08, 2015, 04:04:55 amCan the handset be picked up when the voltage is going into the phone, or will it blow it up?(Its annoying that the phone that i have being given I can't pull it apart and modify it)

author: ianscott
author_rank: Contributor
timestamp: February 08, 2015, 04:18:53 am
content: Quote from: Muttley Snickers on February 08, 2015, 04:14:53 amIm in Victoria, about 2 hours from Melbourne. I need it for around 25/2/15 to the 15/3/15

author: TerminalJack505
author_rank: Super Contributor
timestamp: February 08, 2015, 05:15:09 am
content: If you're handy with electronics then it looks like you can make your own ringer circuit for peanuts.The first two circuits onthis pagelook like a good starting point.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 08, 2015, 06:22:37 am
content: Easiest is to use a cheap VoIP adapter. Other than that, you might have some luck using a small isolation transformer (or an AC wall wart driving a small mains transformer in reverse) to get an isolated 100V AC or so.

author: David_AVD
author_rank: Super Contributor
timestamp: February 08, 2015, 07:26:48 am
content: I have a phone ringer box for sale that will do what you want. Give me a PM if interested.

author: Red Squirrel
author_rank: Super Contributor
timestamp: February 08, 2015, 11:36:22 am
content: I can confirm it's at least 120v if higher. I think it's actually 170v, but it's a lower frequency I believe. Note to self: When reaching for a wire on a MDF, try not to have your face squished against a cable pair block. Out of 100 lines, there's a half decent chance someone is calling one of them.The device that makes the phone ring is called a ring generator, might be able to find one and see if you can make it work on it's own. Normally they are plug in modules for the phone switch. Ex: DMS100. They're on top of the line card drawers. If I had to guess they produce a constant voltage, and the relay on the line card is what makes it go on and off.

author: janoc
author_rank: Super Contributor
timestamp: February 08, 2015, 12:42:33 pm
content: If it is for a stage, why just not gut the phone and put a normal DC door bell inside? Then you can ring it safely with a battery and a push button ...Alternatively, you can pre-record the ringing noise and replay using a speaker installed in the modded phone.I don't think that the requirement was that the phonehas to work. Cheat, it is theatre! And you also avoid having to tinker with high voltage circuitry - temporary wiring, often taped down and installed far from acceptable standard as is often the case in similar circumstances is only asking for someone getting accidentally zapped or something getting shorted and smoking. Not worth the trouble, IMO!

author: Pjotr
author_rank: Frequent Contributor
timestamp: February 08, 2015, 01:13:26 pm
content: The ring signal is a burst of 60V - 100V Rms. Here it is at 10 Hz. Google for a free SW tone burst generator, feed the signal to an audio amplifier en drive the phone with a reversed small mains transformer to step up the voltage

author: G7PSK
author_rank: Super Contributor
timestamp: February 08, 2015, 04:15:08 pm
content: You could get an old field telephone, they had a crank on the side that generated the ring pulse.

author: ianscott
author_rank: Contributor
timestamp: February 10, 2015, 01:55:44 am
content: hey guys,The phone needs to be a digital sounding one (not a old school bell). The phone is very similar to this one pictured below.ThanksIan

author: calexanian
author_rank: Super Contributor
timestamp: February 10, 2015, 03:03:19 am
content: Typically the type of phone pictured there has either a large zener or a neon or gas spark gap tube with the yelping circuit in series with it and it yelps along with the low frequency ring signal. 90 volts is what it takes here in the states to get them to ring. Look up a ring generator. You can get them second hand online. Be careful though. They can zap you and knock you on your butt pretty good! Old fashioned bell ring telephones just have the coil to the clapper arm of the ringer connected across the line. This had two purposes. One, the phone will instantly ring when the ring signal comes, and two tells the telephone company a phone is connected by keeping the circuit closed. The audio signal is so low it does not move the clapper enough to ring. On some old phone designs the clapper was sensitive enough that you could hear the audio off of it like a speaker if the design did not take it out of the circuit when the receiver was off the hook.

author: miguelvp
author_rank: Super Contributor
timestamp: February 10, 2015, 05:46:17 am
content: Someone already mentioned a VOIP device. I would recommend a MagicJack but that's for the US only so you'll need a 2nd one so it would be a local call or get someone from the US to ring you

author: lincoln
author_rank: Regular Contributor
timestamp: February 10, 2015, 05:53:27 am
content: Hello,I have done this in the past, #1. for simplicity is a field phone with a crank. #2 was wire an audio amp and have a signal generator audio test CD with a 20 Hz tone. Bonus points that it can be controlled via the sound board.link

author: cc83
author_rank: Contributor
timestamp: February 10, 2015, 07:45:30 am
content: Quote from: ianscott on February 10, 2015, 01:55:44 amEven easier. Why not just use a uc and program the ringing tone, then just use a pin to signal the uc to turn the tone on, you could easily program a attiny85 (or other uc) to output the tone to a amplifier, if the phone is on a desk or anything you can hide the electronics and speaker in there. You could even use the line to the phone for signaling.I assisted a production years ago where there was a ringing phone needed and it was hard to hear one on stage so we wound up playing it through the sound board. If you want it to sound like it's coming from the phone on stage you can see if the sound guy can use some creative mixing to give that illusion.

author: calexanian
author_rank: Super Contributor
timestamp: February 10, 2015, 11:05:55 pm
content: Or a bell ringer that sounds like a telephone bell and use a 555 to cycle it on and off when somebody pushes a button offstage.

author: calexanian
author_rank: Super Contributor
timestamp: February 10, 2015, 11:06:46 pm
content: Or better yet just record the sound of a telephone ring, or fine one online and just play it!

author: Seekonk
author_rank: Super Contributor
timestamp: February 11, 2015, 03:10:51 pm
content: One thought is to use a Self-Oscillating HALF BRIDGE basically a 500V 555 oscillator like IR51HD224. I have a number I bought for about a buck each. Two in series would give you spacing and tone. Personally I would do it with $2 mega328 and a FET.

author: David_AVD
author_rank: Super Contributor
timestamp: February 11, 2015, 09:17:33 pm
content: The ringer I designed uses a micro driving a couple of NPN transistors which in turn drive the 12V winding of a small mains transformer. The 240V winding feeds the phone output. I also have off-hook detection so it stops ringing when the phone is picked up. It has start and stop button inputs as well. The micro allowed me to create Australian and USA ring cadences.

author: jlmoon
author_rank: Unknown
timestamp: February 11, 2015, 09:29:37 pm
content: Quote from: ianscott on February 10, 2015, 01:55:44 amMake a chopper out of a 555 timer set for 20 cps wave form at 5 volts and hook to the opto isolator (transistor side - observing correct bias) that senses the incoming ring voltage on Tip and Ring. Control the power to the 555 and you can ring that electronic phone until the cows go home. Just like the phone company does but on the other side of the isolator..

author: jlmoon
author_rank: Unknown
timestamp: February 11, 2015, 09:31:33 pm
content: Quote from: calexanian on February 10, 2015, 03:03:19 amI remember the days when electrical storms would come through and the phone would go DING.... I knew lighting hit the phone lines nearby.

author: spencerlinn
author_rank: Contributor
timestamp: February 12, 2015, 03:15:26 am
content: I know this is probably way too much equipment to buy just to get a phone to ring, but perhaps a Cisco 2801 or 2811 router with an FXS card would work? The FXS cards have at minimum a few RJ11 jacks and as per the name, act as a Foreign Exchange Station - generating the analog voice signals and ringing voltage as well. Normally these FXS cards are used in a Cisco VoIP phone system to allow it to interoperate with analog phones as well, but you might be able to set up just two analog phones and call one from the other, or even use the Cisco IP Communicator software phone on a laptop with WiFi (and a WiFi router plugged into the Cisco router with related IP network configured) to initiate the ringing. It wouldn't involve the telco, and you can set the ringing to any cadence and frequency you like, I believe. Like I said, it'd be a fair bit of setup and probably not worth it for a single use, but hey, it'll give you plenty of flexibility to set up your system and not have to modify any phones!

author: tautech
author_rank: Super Contributor
timestamp: February 12, 2015, 03:43:58 am
content: Quote from: ianscott on February 08, 2015, 03:30:45 amEasy really.Here in NZ std phones on the same line as another can be all rung with 137 entered in the keypad and then hung up.Handy for the wife to let me know when its dinner time when I'm in the garage.For the OP's needs, set up the stage phone on an extension jack with another working (live) phone, turn off the ringer on the remote one, then have somebody dial the stage phone on cue.It will ring until picked up.So corner an Aussie Telco tech and confirm the self-dial # and you'll be set to go.

author: janoc
author_rank: Super Contributor
timestamp: February 12, 2015, 10:44:49 am
content: Quote from: tautech on February 12, 2015, 03:43:58 amI think the point was to ring the phone when youdon't haveit hooked up to a landline. Otherwise the OP could simply call it from another phone, no?

author: David_AVD
author_rank: Super Contributor
timestamp: February 12, 2015, 11:07:37 am
content: Exactly. Relying on a real land line is not really practical for most theatre applications.

author: Zucca
author_rank: Unknown
timestamp: February 12, 2015, 11:50:36 am
content: I would have played a telephone sound by using the theater speakers. Not realistic, but good enough.

author: kolbep
author_rank: Frequent Contributor
timestamp: February 14, 2015, 05:13:10 pm
content: With everything going to VOIP nowadays,there are lots of offices with 2nd hand analogue PABX's lying around (Dave even did a teardown of one when he moved into the EEVblog world headquarters).You just have 2 hook the 2 phones up to it, and then dial the internal number for the stage phone (eg 204 or whatever).And you do not need an external telko line, just the 2 phones plugged in (on on stage, one off stage), and the power into the pabx.p