hansen@pegasus.att.com (Tony L Hansen) (02/10/91)
A group I'm associated with is putting on a play and a phone will be
used on the set. How would I hook up the phone so that I can cause it
to ring on demand? Preferably, I'd like to have some sort of switch or
push button which I can push and have the phone ring. (Please email
the answers directly to me as this group expires too quickly on my
machine and I don't always get a chance to read the group in time
before things disappear.)
Tony Hansen
att!pegasus!hansen, attmail!tony
hansen@pegasus.att.com
tony@attmail.com
[Moderator's Note: Unless you want to go to a lot of hassle re-wiring
the phone itself, why not just get a small doorbell from a hardware
store; a battery to drive it and a simple switch. Have it off-stage
and activated at the proper time(s). The actors can pick up the phone
on demand. The audience won't know the difference. PAT]gabe@sirius.ctr.columbia.edu (Gabe Wiener) (02/13/91)
In article <74347@bu.edu.bu.edu> hansen@pegasus.att.com (Tony L Hansen) writes: >A group I'm associated with is putting on a play and a phone will be >used on the set. How would I hook up the phone so that I can cause it >to ring on demand? Preferably, I'd like to have some sort of switch or >push button which I can push and have the phone ring. (Please email >[Moderator's Note: Unless you want to go to a lot of hassle re-wiring >the phone itself, why not just get a small doorbell from a hardware >store; a battery to drive it and a simple switch. Have it off-stage Maybe he doesn't do that because a doorbell sounds NOTHING LIKE A PHONE. There are little boxes you can get from those telecom catalogs that put out ringing current. I see 'em all the time in phone stores when they just HAVE to show off how the duck phone really quacks when it rings. It should be a simple matter to find a dealer who uses one of these gadgets and ask him where he got it. Gabe Wiener - Columbia Univ. gabe@ctr.columbia.edu gmw1@cunixd.cc.columbia.edu 72355.1226@compuserve.com
msb@sq.com (Mark Brader) (02/17/91)
>> A group I'm associated with is putting on a play and a phone will be >> used on the set. How would I hook up the phone so that I can cause >> it to ring on demand? ... >> [Moderator's Note: ... why not just get a small doorbell from a hardware >> store; a battery to drive it and a simple switch. Have it off-stage...] > Maybe he doesn't do that because a doorbell sounds NOTHING LIKE A PHONE. This is not necessarily an obstacle. Seems to me that most PHONES I encounter today, other than the 2500 set I have at home, sound "NOTHING LIKE A PHONE"! Seriously, though, if it's okay for the sound not to come from the phone itself, the easiest thing would probably be a tape recording of a phone. But I suspect that this is NOT okay, unless the phone is at one side of the set. People in the front rows can tell if the sound is coming from the wrong place. Hmm. You could always put an actual, connected phone onstage. To keep wrong numbers from ringing it at the wrong time, unplug the extension cord at the other end except at the critical moment. Mark Brader, SoftQuad Inc., Toronto, utzoo!sq!msb, msb@sq.com
John_Richard_Bruni@cup.portal.com (02/18/91)
Pat, This may be hazardous to one`s health, but I have on several occassions seen phones hooked up to AC to ring the bell for plays ... you get a momentary-on switch and someone in the stage crew pushes the button to simulate the ring. One stage manager told me the extra voltage and frequency was handy because the phone rang *MUCH* louder than normal, which was ideal for theater use. I am sure that the phones in question were 1970`s vintage or earlier. This is all I know about the subject. I`ll leave the technical discussion of the pros and cons to those more in the know. Regards, Rocky [Moderator's Note: What you are suggesting is a *highly dangerous* practice which could -- would !!! -- damage the phone beyond future use to say nothing of hurting the hapless person who picked it up at the wrong time. Don't do it! PAT]
foos@uunet.uu.net (John Foos) (02/19/91)
John_Richard_Bruni@cup.portal.com writes: > This may be hazardous to one`s health, but I have on several > occassions seen phones hooked up to AC to ring the bell for plays ... > [Moderator's Note: What you are suggesting is a *highly dangerous* > practice which could -- would !!! -- damage the phone beyond future I hate to dissagree, but... I am the proud owner of a Western Electric (?) desk phone. I don't know its age, but it is the same model that Bogie talks on in Casablanca. It is quite heavy and when the dial is released it makes a pleasant whir. I got it from a retired electrician who had used it for many years as a 120 volt tester. He had wired a power plug to the cord and would test a circuit by plugging in the phone. If it rang the circuit was live. I have used it for many years now and the sound quality is better than any modern phone I have used (as a phone I mean). I would imagine, though, this is the exception rather than the rule. By the way, were these earlier phones made of bakelight (sp?) rather than plastic?
roy@alanine.phri.nyu.edu (Roy Smith) (02/19/91)
John_Richard_Bruni@cup.portal.com writes: > I have on several occassions seen phones hooked up to AC to ring the > bell for plays Our Moderator replies: > What you are suggesting is a *highly dangerous* practice ... OK, I'll agree that it's a Bad Idea, and I'm not advocating that you do it, but let's think about this for a minute. Just how dangerous could it be? Typical ringing voltage is 90-100 volts (the guy who runs our shop takes advantage of this by putting a regular incandescant light bulb across his phone line so he can see the phone ring when his noisy machines are running). The AC mains is about 120, so we're only talking about a 25% or so overvoltage condition. Surely that won't damage the phone. Roy Smith, Public Health Research Institute 455 First Avenue, New York, NY 10016 roy@alanine.phri.nyu.edu -OR- {att,cmcl2,rutgers,hombre}!phri!roy [Moderator's Note: An actual phone line not being used has closer to forty volts DC on the line doesn't it? It goes up to ninety volts only when ringing ... and only around ten volts DC when off hook ... I think my figures are correct. But a straight 110-120 volts AC coming into it for even a few seconds? Never! Speaking of which, do any of the older readers remember the stories of the infamous 'Tucker Telephone' ... the torture device the Warden at Tucker Prison Farm in Arkansas used on recalcitrant and defiant prisoners for many years until the Supreme Court made him stop? An old, rural-style phone with a crank, and two wires coming out of it ... as the Warden cranked the phone, one wire would be clamped to the prisoner's ear lobe, and the other attached to his ... oops, we're out of space for this issue. Sorry I couldn't finish the story. :) PAT]
rees@pisa.ifs.umich.edu (Jim Rees) (02/20/91)
In article <telecom11.129.6@eecs.nwu.edu>, John_Richard_Bruni@ cup.portal.com writes: > This may be hazardous to one`s health, but I have on several > occassions seen phones hooked up to AC to ring the bell for plays ... My recommendations are: 1. Don't do it. 2. If you must, at least put it in series with a 1/4 amp fuse and a 5K resistor. The resistor will limit the loop current so as to lessen, but not eliminate, the chance of killing yourself or the phone. You should also use an isolation transformer. 3. Better yet, don't even think about doing it.
ccplumb@rose.uwaterloo.ca (Colin Plumb) (02/20/91)
John_Richard_Bruni@cup.portal.com wrote: > This may be hazardous to one`s health, but I have on several > occassions seen phones hooked up to [120 V] AC to ring the bell > for plays ... > [Moderator's Note: What you are suggesting is a *highly dangerous* > practice which could -- would !!! -- damage the phone beyond future > use to say nothing of hurting the hapless person who picked it up at > the wrong time. Don't do it! PAT] It's awfully presumptuous of me, but I'd like to suggest otherwise. Remember, we're talkking genuine Bell mil-spec 500 sets here. Indestructible by any means up to and including inquisitive young TELECOM readers. I'm quite sure raw AC would quickly turn any electronic phone into a puddle of plastic, but good old-fashioned mechanics isn't as fragile. Certainly the plastic on that nice solid handset is more than enough to keep 120V from my tender skin. The main danger is picking the phone up during a ring and thus connecting that line current to the speaker. I think that's a Zener in there protecting the speaker, but that won't last long. To allay everyone's fears, I suggest disconnecting the network before (ab)using a telephone in this way. My "500 12/77 Made in Canada" I have lying open in front of me has the line connecting to clips labelled L1 and L2 on the network (for non-techies, that's the little bit of circuitry in the phone. Three capacitors, one transformer, and two unidentified white boxes "1.5J250P" and ".12K250P"), which have leads to the ringer and other places. The L1 and L2 connectors are not connected to anything on the PC board, so just unplug the one extra wire from L1 and two from L2. You can stash them in the unused connectors E1 and E2 if you like. The ringer has four wires, the other two which go to A and K on the network. These are connected by PCB traces to a. .47/400V capacitor. It can probably take it... After this modification, the only thing you can fry is the ringer itself, and I'd be really surprised if that couldn't take a measly 100% overload. No, this isn't particularly good for the phone, but I've never seen theatre people worry about what's healthy. ("I'll be glad to spray-paint the backdrop with the ventilation fans out of order!") Colin [Moderator's Note: But more important, for their own personal safety you figure they will know enough to re-wire the network of the phone according to your instuctions? Mighty big assumption! PAT]
floyd@ims.alaska.edu (Floyd Davidson) (02/20/91)
Roy Smith writes: >John_Richard_Bruni@cup.portal.com writes: >> I have on several occassions seen phones hooked up to AC to ring the >> bell for plays >Our Moderator replies: >> What you are suggesting is a *highly dangerous* practice ... > OK, I'll agree that it's a Bad Idea, and I'm not advocating >that you do it, but let's think about this for a minute. Just how >[Moderator's Note: An actual phone line not being used has closer to >forty volts DC on the line doesn't it? It goes up to ninety volts only >when ringing ... and only around ten volts DC when off hook ... I >think my figures are correct. But a straight 110-120 volts AC coming >into it for even a few seconds? Never! That is not really such a bad idea, *if* you do it right. *If* you do it wrong it is a *really* bad idea. Normal ringing voltage is about 100 volts at 20 Hz, and it is truely nasty stuff. Getting jerked around by 20 Hz current will teach some true respect. Don't confuse that with a relatively mild 60 Hz shock. (Either one can kill you.) But, the ring voltage is current limited. It is in series with a ballast lamp. Even a dead short will not blow a fuse. In an earlier post someone suggested a fuse and a 5k resister in series with the phone. It probably won't ring the phone. Rig up a lamp socket in series with the phone and a push button switch. Plug in a relatively small lamp, say a 15 watt job. If the phone rings loud enough, that's it, if not then use a larger lamp until it does. One word of caution: Have someone who understands electicity do this. The switch MUST be on the hot side of the wiring. If this is wired correctly there is no more danger from using 60 Hz current than from 20 Hz. Either way you end up with enough juice to knock your socks off if you touch it. And I'll admit to being semi scared to death of 60 Hz house current, but I'm also ten times as scared of 20 Hz ring current. It *HURTS*! Floyd L. Davidson | floyd@ims.alaska.edu | Alascom, Inc. pays me Salcha, AK 99714 | Univ. of Alaska | but not for opinions. [Moderator's Note: No problem! Everyone putting on an amateur play for their school, etc 'understands electricity' don't they? :) PAT]
Barton.Bruce@camb.com (Barton F. Bruce) (02/20/91)
Certainly running a stage phone off 110 is a dangerous idea, but the main problem is that it may well NOT work. The standard 'straight line' ringer will work over the full ringing range phones are rung with - ~16 - 66 hz, BUT the weird frequencies are normally done with tuned ringers designed to ONLY ring at that frequency. The straight line ringers normally are used on 20hz from the CO and 30 hz in a Key system. At 60hz you may need up near 160 volts to get it ringing. Normally ringing is SUPERIMPOSED on DC to provide for ring tripping, but the DC is blocked by the .5 mfd cap, so is irrelevant for clanging the bell. N.B. that the original post was by an AT&T Bell Labs type. Early on I mailed to him suggesting simply grabbing (at work presumably there should be LOTS somewhere) a small plug in key system ringing generator like the WE 118A. It is the size of a FAT modem transformer, but has a short cord + plug rather than built in prongs. I suggested wiring the phone directly to it, and plugging it in to the stage light panel so some existing switch would ring the bell. These supplies are 30hz and are very current linited. For someone not working for Bell Labs, the local phone company is apt to help with school plays - free.
gabe@sirius.ctr.columbia.edu (Gabe Wiener) (02/21/91)
In article <telecom11.134.3@eecs.nwu.edu> motcid!foos@uunet.uu.net (John Foos) writes: > I hate to dissagree, but... > I am the proud owner of a Western Electric (?) desk phone. I don't > know its age, but it is the same model that Bogie talks on in > Casablanca. It is quite heavy and when the dial is released it makes > a pleasant whir. I got it from a retired electrician who had used it > for many years as a 120 volt tester. He had wired a power plug to the > cord and would test a circuit by plugging in the phone. If it rang > the circuit was live. I have used it for many years now and the sound > quality is better than any modern phone I have used (as a phone I > mean). I would imagine, though, this is the exception rather than the > rule. By the way, were these earlier phones made of bakelight (sp?) > rather than plastic? The danger isn't necessarily frying the phone (though I'm quite sure that with the low level of quality of today's telephones, most of them would fry) as much as it is frying the ACTOR who picks up the phone while wall current is flowing through it. Most early phones from the 20's and even into the 30's were metal. Some of the later models, particularly the first models with internal ringers, were indeed plastic. I don't remember if it's bakelite or not. Gabe Wiener - Columbia Univ. gabe@ctr.columbia.edu gmw1@cunixa.cc.columbia.edu 72355.1226@compuserve.com
floyd@ims.alaska.edu (Floyd Davidson) (02/21/91)
In reference to using 117 VAC 60 Hz to ring a phone: In article <telecom11.139.11@eecs.nwu.edu> gabe@sirius.ctr.columbia. edu (Gabe Wiener) writes: > The danger isn't necessarily frying the phone (though I'm quite sure > that with the low level of quality of today's telephones, most of them > would fry) as much as it is frying the ACTOR who picks up the phone > while wall current is flowing through it. I posted my view on this subject earlier. Since Pat seems to have missed the essense of what I said, and this article more or less falls in line with Pat's feelings that it is intrinsically and specifically hazardous... One more time: 100 VAC 20 Hz is JUST as dangerous, if not more so, that 117 VAC 60 Hz. Using house current to ring the phone is no more, and no less, dangerous, than ANY other reasonable way you can make the ringer work. In fact 60 Hz current may be less dangerous than 20 Hz. 60 Hz current can cause all the normal damage everyone is familiar with if you get a shock, but 20 Hz does something that perhaps most people are not aware of: Your muscles can and will go into clonic-tonic jerks at the 20 Hz rate. They cannot respond that way to 60 Hz current as it is too fast. Hence, in one way, it might be said that 20 Hz current is MORE of a problem than 60 Hz. 20 Hz current will certainly hurt more and usually will be harder to get loose from, than 60 Hz. The difference between having 90-100 VAC and 105-120 VAC (ringing voltage vs. house current voltage) is insignificant. Hence what I am saying is that using 60 Hz is a viable way to ring the phone, just as 20 Hz is, IF WHOEVER HOOKS IT UP KNOWS WHAT THEY ARE DOING. If they don't it is just as hazardous either way. If the phone is well enough insulated for the normal ring voltage, it is well enough insulated for house current. And it certainly is. Floyd L. Davidson | floyd@ims.alaska.edu | Alascom, Inc. pays me Salcha, AK 99714 | Univ. of Alaska | but not for opinions.
kevin@gatech.edu (Kevin P. Kleinfelter) (02/22/91)
So take a toy train transformer and use it. Use an AC one. Crank it
from 0 to the point where you get a ring. If 120V is a problem, the
12V coming from the transformer should not be. If 12V is not enough,
get a 24V transformer.
Kevin Kleinfelter @ Dun and Bradstreet Software, Inc (404) 239-2347
{emory,gatech}!nanovx!msa3b!kevin
Look closely at the return address. It is nanovx and NOT nanovAx.jeh@dcs.simpact.com (Jamie Hanrahan) (02/23/91)
In article <telecom11.138.7@eecs.nwu.edu>, Barton.Bruce@camb.com (Barton F. Bruce) writes: > [you really need to be close to 20 or 30 Hz to do this right] How about: Connect an audio function generator to a line-level input on a reasonably-powered (say 30 W) audio amp. Connect speaker-level output of amp to the 8-ohm side of a 70-volt-to-8-ohm transformer, such as is used in PA systems. Connect 70-volt side of transformer to phone. Or, try any audio output transformer you happen to have lying around. You will have to experiment a bit with the gain on the amp to get the right voltage into the phone. (As always, start low and work up, not the other way around!) Using an audio amp and a function generator is an old laboratory trick for getting variable-frequency power, rather than just waveforms, at voltages and currents much higher than any function generator can provide. Typically it's used when you want something approximating an AC power supply (=> low source impedance) so a good transistor amp with high power and a very high speaker damping factor (50:1 is good) is used, with no output transformer. An old favorite (mostly because it seems to be indestructible) is the Crown DC-300A, so named because of its flat freq response at full- power from (near) DC to 300 KHz. If you don't have one of those, any brute-force amp with a hefty transformer and lots of output transistors should do. (Don't try this with Carver or other amps with trick power supplies) Jamie Hanrahan, Simpact Associates, San Diego CA Internet: jeh@dcs.simpact.com, or if that fails, jeh@crash.cts.com Uucp: ...{crash,scubed,decwrl}!simpact!jeh
POWERS@ibm.com (02/23/91)
I can't believe no other reader has suggested this - if I missed it, please accept my apologies. Buy a surplus EE-8 field telephone, or the magneto from same, or similar magneto, from any of numerous surplus vendors (including Edmund Scientific, if I remember correctly). These puppies are still quite plentiful and sold under various names, and for various purposes, such as inducing worms to surface. Connect the output to the telephone to be rung. Turn crank, using ringing cadence desired. No mains power is required. Damage from shocks (very painful, but unlikely with the simplest precautions) is limited to the duration of circular cranking by a human being and a limited generating capacity. Anyone got a safer and/or simpler solution?
gaarder@theory.tn.cornell.edu (Steve Gaarder) (02/24/91)
The simplest thing, seems to me, would be to use a ring generator, since ringers are tuned to 20 HZ and don't work well at other frequencies. The easiest unit to use just might be one of those hand magnetos -- just what phones used to use. If you're at a school, there's a good chance the science dept has one or two for demos. Otherwise, try Edmund Scientific. Fair Radio Sales often has magneto phones, and they also have a 20HZ vibrator-type ring generator that works from 100 VDC input. Steve Gaarder gaarder@theory.tn.cornell.edu
joe@mojave.ati.com (Joe Talbot) (02/28/91)
Use a REAL ring generator and an unmodified REAL phone. An outfit called Minnesota Telephone installers is selling a small ring generator that (I beleive) is the one used on the old shoebox four line key systems. It's a very small black cube with a short AC cord on it and two screws that have about 100 volts at 30 hertz (unplug before connecting). It will ring an unmodified phone of about any vintage (your play may be set in the thirties as my high school play was, so I used a 300 desk set. The 300 wasn't made until the fourties but nobody could tell, I didn't think a trimline was appropriate). Just run a cable to the phone's location (1 pair bridged ringing!). Connect the phone at the one end. At the other end, connect one wire from the pair to a screw on the generator, connect the other to a push button and the other side of the button to the other screw on the generator. Push the button to ring the phone (wow). Minnesota Telephone installers: (612) 894-1904 You want a WE 118A ring generator advertised for $30 in Telephone International. (Try bargaining; they can't be selling that many. Mention what it is for. Many of these secondary vendors are very helpful and flexible. I have never done business with these people, however.) joe@mojave
tad@ssc.UUCP (Tad Cook) (03/03/91)
One important factor when comparing the danger of 20 Hz 100vac with 60 Hz 117vac: The ringing voltage from the phone company is going through a loop that is anywhere from a few hundred to a couple of thousand ohms. You don't have that with the power line. Also, the telco loop is set up to stop sending ringing current immediately when it detects some current draw. Hooking the power line to a wire pair to the phone on stage, you don't have that advantage. Play it safe and do what many film and TV production companies have done ... use a Proctor 46220 Ringdown circuit. With this product, you can even TALK to the actor on stage from an offstage phone, and feed him his lines! The 46220 is $179 from: Proctor & Assoc. 15050 NE 36th St. Redmond, WA 98052-5317 206-881-7000 internet: 3991080@mcimail.com Tad Cook Seattle, WA Packet: KT7H @ N7ENT.#WWA.WA.USA.NA Phone: 206/527-4089 MCI Mail: 3288544 Telex: 6503288544 MCI UW USENET:...uw-beaver!sumax!amc-gw!ssc!tad or, tad@ssc.UUCP
ROCKY@cup.portal.com (03/11/91)
Just a couple of quick notes on this topic. First of all, due to the kind contribution of someone whose name I unfortunately cannot remember, I am now holding a catalog from Proctor. Their 46220 'Telephone Hot Line Automatic Ringing Private Line` includes its own power supply and ringing generator system. It even comes with an optional battery pack. As was mentioned in the newsgroup earlier, this is clearly the best way to go. Prices aren't listed in my copy. Once more, to contact them: Dave Koshak, National Product Line Sales Manager Proctor & Associates 15050 Northeast 36th Redmond, Washington 98052 1-800-824-9719 For those brave souls who want to try a cheaper method, get a copy of a truly amazing surplus catalog -- I didn't know such a catalog still existed and surplus fans all should get a copy -- catalog WS-90 from: Fair Radio Sales Co. P.O. Box 1105 Lima, Ohio 45802 419-223-2196 On page 17 they have a handcrank magneto generator removed from telephone equipment for $15 used/checked. Catalog says use as 'remote signaler (ring bells, buzzers), or as ~worm shocker~.` For the truly adventuresome they also have a 20 Hz inverter module on p. 5 that produces 20 Hz 65 V 50 ma ringing signal, but the rub is you need 110V *DC*. This little gadget is $7.95, used. One final note, the bug-detectors on the market today (someone mentioned seeing one in a mailorder catalog) would only work on bugs of a nature so obvious that I doubt anyone uses them. And, as Operation Sundevil showed, if a *LEGAL* wiretap is being placed on your phone by the government, all they do is call up the phone company and the computer does the deed for them. So don`t waste your money, is my recommendation. One note in the realm of blue sky: someone I know in the chip labs at Cal-Berkeley says there is now a tiny little chip out that has on it a solar cell that puts out enough power to run the transmitter that is also on this chip, and with the transmitter comes a micro-etched plate that functions as a transducer. Thus, a self-powered bug that is nearly too small to be visible ... please don't yell at me if this is too much for you to believe as I am only repeating gossip ... thanks. Rocky ROCKY@CUP.PORTAL.COM
Tad.Cook@cs.washington.edu (03/15/91)
In article <telecom11.194.5@eecs.nwu.edu>, ROCKY@cup.portal.com writes: > Just a couple of quick notes on this topic. First of all, due to the > kind contribution of someone whose name I unfortunately cannot > remember, I am now holding a catalog from Proctor. Their 46220 > 'Telephone Hot Line Automatic Ringing Private Line` includes its own > power supply and ringing generator system. > Once more, to contact them: > Proctor & Associates > 15050 Northeast 36th > Redmond, Washington 98052 > 1-800-824-9719 The 46220 sells for $179. They are also stocked by GTE Supply and North Supply. Proctor can also be reached at: phone: 206-881-7000 Fax: 206-885-3282 internet: 3991080@mcimail.com Tad Cook Seattle, WA Packet: KT7H @ N7ENT.#WWA.WA.USA.NA Phone: 206/527-4089 MCI Mail: 3288544 Telex: 6503288544 MCI UW USENET:...uw-beaver!sumax!amc-gw!ssc!tad or, tad@ssc.UUCP