Classic Rotary Phones Forum

Telephone Switching => General Switching Discussions => General PAX & Intercom Systems => Topic started by: stopthemachine on January 13, 2011, 09:40:30 PM

Title: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on January 13, 2011, 09:40:30 PM
Hi all,

I'm pretty new to this site (and I LOVE it!), but certainly not to phones--however, I need some help with intercoms/phones used in a regular house set-up.

I've read some great posts on here about hooking magneto phones together to ring in a house, also the intercom Connecticut phones, etc.

OK, I am in the processing of fixing up an old, three-story house (slow but steady process due to limited funds at times)--the old plaster walls have been knocked out, and in the (hopefully) next few months, drywall will go back up.  As a "phone-atic," I have greatly considered the idea of hooking up some kind of private phone system into the house, but I'm not sure what would be the best plan.

The magneto phones are cheap enough to pick up on eBay (SC and Kellogg especially), but would that be the best set up?  I think this might be the option to go with--and a way to make good use of the crank phones which often get neglected.  Now, I know I'd need a battery source to actually make voice connection between phones so would it be a daunting task to wire the phones up together...?  Would a switchboard of some sort be a necessary option/alternative?

I've also seen the Connecticut intercoms which are cute, but I am guessing that you could only hook two up together? 

I would love to hear what those with intercom experience (or anyone else for that matter) would suggest. 

Thanks in advance,
Dan  8)
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on January 14, 2011, 01:37:56 AM
If I had an opportunity like that, I'd simply wire the house for telephone service in every room/area, and then put a Panasonic PBX unit in the basement.  That will allow you to use standard telephones in every room AND give those standard phones intercom capabilities.  But when doing that, you can't daisychain the connecting blocks/jacks--each block has to have it's own dedicated line back to the PBX. 
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Greg G. on January 14, 2011, 05:40:11 AM
Quote from: bingster on January 14, 2011, 01:37:56 AM
If I had an opportunity like that, I'd simply wire the house for telephone service in every room/area, and then put a Panasonic PBX unit in the basement.  That will allow you to use standard telephones in every room AND give those standard phones intercom capabilities. 

First thing I thought of too, easier and much less "daunting" to use a PBX.  You would just have to dial the extension #.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: dsk on January 14, 2011, 06:16:31 AM
I have done mush of this, actually starting without a good plan.  :'(
This has caused some rewiring.  :-\
If you are going to connect more than 5 magnetos together you will need to consider a manual switchboard, and someone to operate it :D
If this really is an option all wires should be ending up at that location.
The only other solution is to choose a central point in the hose, Basement, attic, or a technical room. From this point you should run wires to each point you may need a telephone or wired internet connection. Cat 5 works well for me.
Each cable contains 8 wires (4 twisted pairs) 2 pairs is usually used for internet. The other to may well be used to 2 different telephone connections. This may slow down the internet in that short period the ringer rings, but probably not.
At  each location you terminate either  an ordinary internet jack, and use a splitter when needed, or you put up a double jack.
At the central point you may end up in some kind of panel. I have used Krone  LSA+  http://tinyurl.com/6lx2y3v
At this point you may patch the wires as you want, and you may reconfigure everyting without  lots of work. You may put up a switchboard or a pabx later.
(The Panasonic analog pabx 's like kxt 616 or 308 is outstanding!)

:) Just remember to put one cable to this point from  1 where your phoneline enters the house, and from where your internets coming in. 

It may be smart do do the same with TV antenna outlets.

dsk
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on January 14, 2011, 10:06:49 AM
Quote from: Brinybay on January 14, 2011, 05:40:11 AM
Quote from: bingster on January 14, 2011, 01:37:56 AM
If I had an opportunity like that, I'd simply wire the house for telephone service in every room/area, and then put a Panasonic PBX unit in the basement.  That will allow you to use standard telephones in every room AND give those standard phones intercom capabilities. 

First thing I thought of too, easier and much less "daunting" to use a PBX.  You would just have to dial the extension #.
I think that this Panasonic PBX in the basement sounds like a great idea.  I hope it's not too technical because I surely am not.  Haha.  I have a friend who MAY be able to help me though as he's an electrician, but I won't hold my breath on it.  Would I be able to use both TT and rotary phones on the Panasonic PBX? 

Hey, on top of that, I could always wire a bunch of Connecticut intercoms together, one-on-one, and just make sure I label which room they would reach.  Haha.  That'd actually pretty a funny idea, especially since they're so small.  In my bedroom, I could have one connected to the kitchen; then, I could have a separate one from my bedroom to the basement, and so forth. 

Ah, the possibilites are endless!  Thanks for your suggestions and keep 'em coming!  :)

P.S.-I wouldn't be able to tap the PBX into the landline, would I?  If not, it's really not a big deal at all. 
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Doug Rose on January 14, 2011, 10:26:48 AM
I have a Panasonic 616 working on default programming (I just pulled the battery strap). 16 intercom extensions that can have up to 4 phones on them. Rings on incoming calls and you can dial ext to ext internally.  I get to show off phones working in my phone room to visitors. The best part is I have phones working of off it in my house and use three ports on my test bench. I have a Comcast Digital line hanging off of this and it works like a champ. The 616 is the BEST investment in phones you will ever make....Doug
Title: Re: Intercoms--Suggestions Appreciated!
Post by: dsk on January 14, 2011, 01:09:40 PM
The 616 is just to hang on the wall, and has 6 telephone jacks for lines to the central office, and 16 jacks for local telephones. Just plug and play.
If you want to change the parameters you will need a special Panasonic telephone for programming. Default should work OK.

dsk
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on January 14, 2011, 02:47:46 PM
And yes, it works with TouchTone and rotary, both.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Adam on January 14, 2011, 03:55:07 PM
Being the local Asterisk geek I'd just like to remind everybody that, while I know the originator of this thread said he wasn't technically savvy, if you know anything at all about computers, you can set up a PBX using the free Asterisk software and any old PC you happen to have laying around.  Then boxes that you plug your phones into (ATAs) that connect with the Asterisk system over a computer network are only about $50 each for two separate phones.

If you have an Asterisk system you can do cool things like being able to set up a phone to ring by dialing your full childhood telephone number, and lots more.

If anyone would like to talk about or needs help with Asterisk, please feel free to send me a private message.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Greg G. on January 14, 2011, 04:29:49 PM
Quote from: stopthemachine on January 14, 2011, 10:06:49 AM
I think that this Panasonic PBX in the basement sounds like a great idea.  I hope it's not too technical because I surely am not. P.S.-I wouldn't be able to tap the PBX into the landline, would I?  If not, it's really not a big deal at all. 

I have mine rigged to my land line.  You can still use it as an intercom by just dialing the extension number.  The signal is different when dialing the extension # on mine, two short rings instead of one long ring.  Here's an example of how mine works, I use a Panasonic 308.  You can hear me dial the two-digit extension.  http://www.youtube.com/watch?v=nmnJPLFgPBU (http://www.youtube.com/watch?v=nmnJPLFgPBU)

I just ran a mod-to-mod cord from the nearest jack to Com 1, then plugged the phones into the extension jacks on the PBX.  Kinda cool the way they all ring in numerical sequence with each signal sent.  You could hook a few up, call your land line from your cell, then see if you can make it from one end of the house to the other before the farthest phone finishes ringing!  My place isn't big enough for that, but my goal is to find 5 phones that have the right pitch so that they play the Close Encounters tune!
Title: Re: Intercoms--Suggestions Appreciated!
Post by: AE_Collector on January 14, 2011, 08:45:43 PM
I had a telephone based intercom working in my parents house when I was a teenager. I got an old AE 10 station electromechanical intercom unit and began installing seperate telephone sets as stations around the house. This system had no access to the phone line, it was strictly an intercom with single digit dialling to the other stations. It was a common talking (single channel) system as well and the ringing was accomplished via a second pair to each telephone with a 10 VAC buzzer in each phone. All the Intercom did was supply talk battery to any off hook phone and the mechanical selector switch determined which phone/buzzer to signal. With an electromechanical selector switch it sounder great when dialing!

Since about 1980 I have always had sone type of electronic phone system in my house. All of these systems used proprietary digital phones like the Panasonic CAN do as well. I started with a Northern Electric Vantage system (which was the predecessor to the NT Norstar) which was replaced later by a Norstar. More recently I converted to a NT Venture system which handles call display much better than the Norstar did.

Meanwhile, standing by I have a SxS demo unit that can process 7 digit calls. Not sure how it is going to do with Call Display though!

You want to work towards having one distribution point in your home for everything as technology moves forward. I have a BIX panel in the basement where everything in the house terminates. There is a 4 pair from my outside telephone protector feeding to the panel and every station run in the house goes there. My phone system is there as is my security system with all of its runs. All of my network wires terminate there as does all of the coax in my house. I have coax feeds from the cable box outside AND 4 feeds from my Satelitte dish up near the roof. I actually have Cable TV service, a satellite dish AND ADSL based Mediaroom based TV (Telus version of AT&T U-verse TV). Tiime to eliminate some TV providers around here!

Terry
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on January 16, 2011, 10:04:30 PM
All of your suggestions have been very helpful, and I thank you for them.  How much is the Panasonic PBX?  I really hope it's not too complicated!  Haha.

I really would like to install some of those Connecticut intercom-type telephones too because they're cute and seem like they would keep some basic communication between the more important rooms if necessary.  What do you all think?  They can be picked up so reasonably too.  Besides, they'd look classy on the walls!  Haha. (Since most are in pretty decent shape for the most part.)
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on January 16, 2011, 10:07:49 PM
The Connecticut intercoms would probably work well point-to point, but the problem is (as far as I know) they can only be used from one point to one other point.  There's no capability for using more than two in a system.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: GG on February 20, 2011, 04:41:47 AM


Yo Stopthamachine: do both! 

The Connecticut intercoms probably require two wires for talk path plus one additional wire per station for the buzzer path.  So a 4-pair (8-conductor) station cable can handle six separate stations. 

If the occupants of the house are a couple w/o kids, then you can do the magneto phones: if you hear it ring, it's your spouse calling, so it doesn't matter what room you're in.   What I used to do for magneto intercom was use 2 pair, whereby one pair was a power supply: any 6-volt to 12-volt AC adaptor will do, and put a relay coil or similar coil (a 1a2 station buzzer with blue wires will do) in series with the output of the power supply to get rid of most of the nasty hum that most of those have, and provide some protection against shorts.  The other pair was connected as the talk pair between the stations.  Strictly speaking it's "cheating" because the power supply is centralized to all stations, but it's more than acceptable because it works. 

The PBX is most useful when you need to call whoever is in a specific room.  Though you can also hook it up to a paging system and dial the code to page over the speakers:  "Hey kids!  Dinner is on!"

I have a couple of Panasonic 616s around that I'm likely to sell (PBX eng. here, Panasonic dealer), and I'll be putting together price lists for the newer Panasonic hardware as well.  Also 1232s which start out as 8x16s, and some extension cards to expand to 24 and 32 stations; however the station outputs on these is via Amphenol connectors that need to be wired to cross-connect blocks. 

The main thing for residences is, you're usually calling by person rather than by room, because any given person can be in any room.  That tends to lead to the preference for something that'll page throughout a house, or have a distinct ringing sound for each person and have ringer boxes with those sounds installed where they can be heard throughout. 

For example a family of four in a house with two floors plus a basement workshop and attic rec room for the kids:  now you have effectively four floors, and four ringer boxes on each floor: uh-oh, you need to get four of each type of ringer box, and train the family to recognize the sounds:  this one is Dad, that one is Mom, this one is Sister, and that one is Brother.  Then you need to train everyone to dial the "pick up ring" code from whichever phone they are at when they want to answer the common bells.  This assumes a PBX, with enough power to ring four ringer boxes on one extension number. 

Alternately, with magneto phones, you can develop a code ringing system where one long ring = any grownup pick up the phone; and two short rings = any kid pick up the phone.  That usually works pretty well if the kids hang out together.   And then you can do something like "one very long ring around dinner time means everyone to the kitchen for dinner." 

Whatever you're doing, you might also consider integrating an emergency alarm system into it, whereby pushing the red button in any bedroom or kitchen etc. turns on common alarm bells, for example in a fire or if there's a burglar.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on February 20, 2011, 01:03:54 PM
Hi GG,

I love your suggestions, but, unfortunately, I'm not too well-versed in mechanics so I'm in the slow-but-steady explanation category.  Haha.

Now, to begin, where does one find the suggested station cables for the Connecticut intercom phones?  The Conn. phones are merely station-to-station though, right?  Can they be wired to work together on more than a two-intercom set-up?  (So--let's say--anyone on one of six intercoms can pick up and be heard from one of five other different phones?)

I'm glad you suggested both ideas because I have no objections to putting a  Panasonic system AND the Connecticut phones in the hosue together.  Haha.  (If for no other reason, the charm of the Conn. phones as usable intercoms in the house and not just there hanging on the wall or setting in a box.)

In terms of the magneto phones, they are also a simple possibility because some of them are so cheap to pick up on eBay (such as the Leich desk sets). 

Thanks again,
Dan
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on February 21, 2011, 01:15:15 PM
Quote from: stopthemachine on February 20, 2011, 01:03:54 PM
Now, to begin, where does one find the suggested station cables for the Connecticut intercom phones? 

They came with plain solid core copper wire.  Two pieces (or three, depending on where you kept the batteries) would be run from one set to the other.  18 or 20 gauge would be appropriate with a normal setup.

I have the setup instructions if you need them.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on February 21, 2011, 05:08:20 PM
Thank you, Bingster,

Yes, I would greatly appreciate them.  They're really cool, those intercoms.  Besides the intercoms and "toaster" phones (which I just recently acquired after many years), it doesn't seem like they made too much in terms of telephony.

Slightly off topic, but what kind of dials were the "toaster" sets usually fitted with?  Mine seems like an AE dial, but I'm not quite sure...it ticks when the dial is wound up to the finger stop.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on February 25, 2011, 10:58:23 PM
Here are the pages from the instruction booklet.  I don't have a scanner, but I photographed them a while back for another member who had a set of these.  There are four pages, and a couple pages are photographed in two sections.  Click the thumbnails for full-size images:

Cover
(http://i43.photobucket.com/albums/e376/bingsterdc/Conn1.jpg)

Page 2
(http://i43.photobucket.com/albums/e376/bingsterdc/Conn2A.jpg) (http://i43.photobucket.com/albums/e376/bingsterdc/Conn2B.jpg)

Page 3
(http://i43.photobucket.com/albums/e376/bingsterdc/Conn3A.jpg) (http://i43.photobucket.com/albums/e376/bingsterdc/Conn3B.jpg)

Page 4
(http://i43.photobucket.com/albums/e376/bingsterdc/Conn4A.jpg) (http://i43.photobucket.com/albums/e376/bingsterdc/Conn4B.jpg)
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on February 25, 2011, 11:11:01 PM
Awesome!  Thanks, Bingster.

Instead of the dry cells, I take it i use 9-volt batteries then?
Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on February 26, 2011, 06:02:17 AM
#6 dry cells were 1.5 volts, so in a standard installation, you'd have a total of six volts (1.5V X  4 batteries) powering the phones.  I imagine a 6 volt lantern battery would work (you'd have to use the three-wire installation method with the battery at one end only), but I think that I'd avoid using C or D cells.  Even though C and D are the proper 1.5 volts, they probably wouldn't last very long. 
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Jim Stettler on February 26, 2011, 09:11:36 PM
Quote from: stopthemachine on February 25, 2011, 11:11:01 PM
Awesome!  Thanks, Bingster.

Instead of the dry cells, I take it i use 9-volt batteries then?


#6 dry cells are 1.5 volt. I would get a Battery holder from radio shack and use 2 "D" cells.
JIm
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on February 26, 2011, 09:16:29 PM
Jim, would the "D" cell batteries last a while?  I guess I don't want to keep buying batteries every day.  Haha.  Thanks.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Phonesrfun on February 26, 2011, 09:22:21 PM
Quote from: stopthemachine on February 26, 2011, 09:16:29 PM
Jim, would the "D" cell batteries last a while?  I guess I don't want to keep buying batteries every day.  Haha.  Thanks.

It is my experience that a couple of "D" cells in a phone will last many months, depending on the use.  When I was a teen-ager, my neighbor and I had a couple of 500's and a line between our houses, and a 6-volt lantern battery lasted us a couple years.  The normal telephone and intercom talk circuit only draws about 35mA, which is 35 thousandths of an amp, and that is only while the phones are off hook.  When on-hook, they should draw zero current.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on February 26, 2011, 10:13:06 PM
Great advice, thanks, Bill and Jim. 

Bill, Should I do as Jim suggested and just put them in a battery holder from Radio Shack then?  Seems to be the easiest thing.

Thank you all.  Your advice is always appreciated.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Phonesrfun on February 27, 2011, 12:26:49 AM
Quote from: stopthemachine on February 26, 2011, 10:13:06 PM
Bill, Should I do as Jim suggested and just put them in a battery holder from Radio Shack then?  Seems to be the easiest thing.


That's what I do, and it works great.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Jim Stettler on February 27, 2011, 12:35:11 AM
Quote from: stopthemachine on February 26, 2011, 09:16:29 PM
Jim, would the "D" cell batteries last a while?  I guess I don't want to keep buying batteries every day.  Haha.  Thanks.

I think they would, current only flows when they are in use. I don't think you will use them enough for battery life to be a concern.
JMO,
Jim

I just read Bill's post. Great minds think alike.
Title: Re: Intercoms--Suggestions Appreciated!
Post by: GG on February 28, 2011, 08:11:17 AM


I'd suggest using rechargeable batteries and having a recharger.  Costs more to begin with, but less in the long run, and then you won't get stuck if the batteries run down and you don't have a spare set of batteries on hand: just stick 'em in the charger and save a trip to the store. 

Title: Re: Intercoms--Suggestions Appreciated!
Post by: bingster on February 28, 2011, 03:51:52 PM
That's a good idea.  I also wonder if it's possible to use a 6 volt wall charger.  Anybody know if that would work?
Title: Re: Intercoms--Suggestions Appreciated!
Post by: Phonesrfun on February 28, 2011, 04:26:29 PM
Yes, you can, but...

The ordinary wall wart charger probably does not have sufficient filtering to get rid of the hum left over from rectifying the AC into DC. 

Some switching power supplies have better filtering.  For more information on building such a battery eliminator, see the pdf booklet in the section describing the power supply in this thread:

http://www.classicrotaryphones.com/forum/index.php?topic=4361.0

Title: Re: Intercoms--Suggestions Appreciated!
Post by: AE_Collector on March 01, 2011, 12:26:59 AM
Maybe DavePEI will see this and comment. Didn't someone determine that old cell phone chargers have very well filtered DC battery? I think Dave used some to power his magneto phones. Old cell phone chargers are usually easy to locate.

Terry
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on March 01, 2011, 02:22:26 AM
Quote from: ae_collector on March 01, 2011, 12:26:59 AM
Maybe DavePEI will see this and comment. Didn't someone determine that old cell phone chargers have very well filtered DC battery? I think Dave used some to power his magneto phones. Old cell phone chargers are usually easy to locate.

Terry
That sounds interesting, Terry.  It seems like everyone has at least 4 of these that aren't needed anymore too.  That'd be perfect.  :)
Title: Re: Intercoms--Suggestions Appreciated!
Post by: DavePEI on March 01, 2011, 06:02:07 AM
Quote from: stopthemachine on March 01, 2011, 02:22:26 AM
Quote from: ae_collector on March 01, 2011, 12:26:59 AM
Maybe DavePEI will see this and comment. Didn't someone determine that old cell phone chargers have very well filtered DC battery? I think Dave used some to power his magneto phones. Old cell phone chargers are usually easy to locate.

Terry
That sounds interesting, Terry.  It seems like everyone has at least 4 of these that aren't needed anymore too.  That'd be perfect.  :)

What it is is that modern flat cell phone supplies are switching supplies. They don't contain more filtering, but the switching design of the supplies, puts the hum at a much higher frequency than the 60 cycle hum you get out of an older cell supply.

The two types I use are Motorola SPN5185A (5 v), and the SPN4278D (4.4 v) - I got a real deal on a bunch of these. However, I am sure practically any of the flat style switching supplies will work.

Any noise they make is well above the frequencies you can hear in the receiver. I have eight or nine of them providing power for the magneto sets in the museum, and one for the switchboard. Each set will require its own supply.

Dave
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on March 01, 2011, 08:57:18 AM
Quote from: DavePEI on March 01, 2011, 06:02:07 AM
Quote from: stopthemachine on March 01, 2011, 02:22:26 AM
Quote from: ae_collector on March 01, 2011, 12:26:59 AM
Maybe DavePEI will see this and comment. Didn't someone determine that old cell phone chargers have very well filtered DC battery? I think Dave used some to power his magneto phones. Old cell phone chargers are usually easy to locate.

Terry
That sounds interesting, Terry.  It seems like everyone has at least 4 of these that aren't needed anymore too.  That'd be perfect.  :)

What it is is that modern flat cell phone supplies are switching supplies. They don't contain more filtering, but the switching design of the supplies, puts the hum at a much higher frequency than the 60 cycle hum you get out of an older cell supply.

The two types I use are Motorola SPN5185A (5 v), and the SPN4278D (4.4 v) - I got a real deal on a bunch of these. However, I am sure practically any of the flat style switching supplies will work.

Any noise they make is well above the frequencies you can hear in the receiver. I have eight or nine of them providing power for the magneto sets in the museum, and one for the switchboard. Each set will require its own supply.

Dave
Interesting--how do you connect them to the phones and intercoms? 
Title: Re: Intercoms--Suggestions Appreciated!
Post by: DavePEI on March 01, 2011, 09:52:03 AM
Quote from: stopthemachine on March 01, 2011, 08:57:18 AM
Interesting--how do you connect them to the phones and intercoms? 

Just take off the ends, and connect the power leads from the charger to where one would normally attach the battery...

You may have to use a multimeter to identify the output leads of the charger...
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on March 01, 2011, 10:08:41 AM
It's times like these that I wish I were more mechanically inclined. Haha.  Hmmm... anyone care to simplify this for the electronically ignorant such as myself?
Title: Re: Intercoms--Suggestions Appreciated!
Post by: stopthemachine on March 02, 2011, 08:57:41 PM
Quote from: DavePEI on March 01, 2011, 09:52:03 AM
Quote from: stopthemachine on March 01, 2011, 08:57:18 AM
Interesting--how do you connect them to the phones and intercoms? 

Just take off the ends, and connect the power leads from the charger to where one would normally attach the battery...

You may have to use a multimeter to identify the output leads of the charger...
Dave, is there any chance you have a picture as to what this set up looks like?  (A cell phone charger connected to an old magneto...or better yet, intercom phone.)  I'd really like to try this soon, but I'm scared I'll mess something up or cut the cell phone charger wrong. 
Title: Re: Intercoms--Suggestions Appreciated!
Post by: DavePEI on March 02, 2011, 11:52:12 PM
Quote from: stopthemachine on March 02, 2011, 08:57:41 PM
Quote from: DavePEI on March 01, 2011, 09:52:03 AM
Quote from: stopthemachine on March 01, 2011, 08:57:18 AM
Interesting--how do you connect them to the phones and intercoms?  

Just take off the ends, and connect the power leads from the charger to where one would normally attach the battery...

You may have to use a multimeter to identify the output leads of the charger...
Dave, is there any chance you have a picture as to what this set up looks like?  (A cell phone charger connected to an old magneto...or better yet, intercom phone.)  I'd really like to try this soon, but I'm scared I'll mess something up or cut the cell phone charger wrong.  

Well it is so simple, a photo wouldn't help. Find out first where you need to attach battery to the phone. That will have to come from its own schematic. Cut the connector off the cord, find the two power leads with a voltmeter (most have a sensing lead) then connect the negative to the negative on the phone, and the positive to the positive. You need a charger for each phone. As far as cutting the charger wrong, just clean cut off the plug, then strip the wire back a couple of inches...

Dave