Why is a transformer wired to the phone line?

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Old 01-27-21, 05:43 AM
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Why is a transformer wired to the phone line?

I had a friend of a friend ask me this as they just bought an old 'fixer-upper" and I don't know the answer (and I usually do with this type of stuff)

Anyway it says ault KS-20426L3
Western Electric or something like Western

It looks to have gotten overheated in the past! I disconnected it for now and no phones went dead (Land Lines but they are connected to a EMTA/VOIP modem unit.

The house was built in the late 1950's and has wiring from then up to modern stuff (No "Tamper Resistant" receptacles are installed yet Good!)
 

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01-27-21, 05:54 AM
AllanJ
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Typical uses -- To light up the dial or keypad of a phone set for nighttime use, to operate indicator lights where there is more than one phone line (e.g. main, childrens) coming into the house and each phone can select each line (usually not for a conference call) via additional push buttons.
 
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Old 01-27-21, 05:54 AM
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Typical uses -- To light up the dial or keypad of a phone set for nighttime use, to operate indicator lights where there is more than one phone line (e.g. main, childrens) coming into the house and each phone can select each line (usually not for a conference call) via additional push buttons.
 
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Old 01-27-21, 06:17 AM
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They probably had a lighted princess phone.
 
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Old 01-27-21, 06:47 AM
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They probably had a lighted princess phone.
come to think of that yes there was one they found in the basement! It can make calls but no dial light. How would I wire this to work through the EMTA/VOIP modem? The modem has two jacks (for two lines but they only pay for one) I obviously don't want to fry that modem as they don't even own it Charter does.
 
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Old 01-27-21, 09:23 AM
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The princess will work on a regular phone line. It uses the red/green pair of wires for the phone and the yellow and black were for the light up dial. The biggest problem is the princess phone is pulse dialing. Not all VoIP convertors will work with a dial phone.
 
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Old 01-27-21, 10:24 AM
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It looks to have gotten overheated in the past!

Not surprised to hear it appears to have over-heated. Some Ault transformers used for lighted phone sets were responsible for fires. Ma Bell was most unhappy. Soon after, they switched to LEDs in lighted phones and powered them from the phone line.
 
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Old 01-27-21, 11:55 AM
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Sounds like an outdoor telephone ringer.
Look under the eaves for 2 bells or a vented 2" x 4" box.
Check around the house for a 3" x 6" control box & switch to turn the outside ringer on and off.


We still had this setup when I was a kid in the 70s, you usually had about 5 rings to get out of the pool, dash across the backyard, into the house and get to the phone before the other person hung up.

By the 1980s the combination of answering-machine & cordless-phone made things MUCH easier.
 
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Old 01-27-21, 05:44 PM
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The princess will work on a regular phone line. It uses the red/green pair of wires for the phone and the yellow and black were for the light up dial. The biggest problem is the princess phone is pulse dialing. Not all VoIP convertors will work with a dial phone.
I don't know if this test is valid or not but I had used a pulse/tone switchable phone and put it on pulse and I was still able to make a call.

Not surprised to hear it appears to have over-heated. Some Ault transformers used for lighted phone sets were responsible for fires. Ma Bell was most unhappy. Soon after, they switched to LEDs in lighted phones and powered them from the phone line.
I looked at it closer and looked up the part # yep it was a recalled one! I saved it for my "collection" in the do-not use pile along with my factory mistake 5-15P to 5-15P (yes double male ends!)

It still works but I won't use it!
 
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Old 01-27-21, 05:48 PM
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By the 1980s the combination of answering-machine & cordless-phone made things MUCH easier.
I remember living in a busy apartment building in the late 1990's into the early 2000's The old phones were able to be heard on a radio scanner (AKA Police/Fire/Rescue Scanner) 900MHZ phones were easily picked up by it yes I was noisy as a teenager! Some used different talk/receive channels so I would have to find the whole conversation.
 
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Old 01-28-21, 08:40 AM
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Some of the first AT&T phones with lights had separate transformer to power them.

Recall one module was 1 1/2" greenish cube with prongs to plug into wall socket. Two screw terminals for 18? volts for lights.

Sometimes 4 wire cord to phone had 2 wires for sound and 2 wires for lights. Module was in basement near terminal block.
 
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Old 01-30-21, 05:18 PM
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Recall one module was 1 1/2" greenish cube with prongs to plug into wall socket. Two screw terminals for 18? volts for lights.
I still have one and it's still connected, but not plugged in. Mine though is more gray, marked 6-8V Western Electric. Being gray I suspect it's a little older than a green one.
 
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Old 01-30-21, 07:49 PM
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I still have one and it's still connected, but not plugged in. Mine though is more gray, marked 6-8V Western Electric. Being gray I suspect it's a little older than a green one.
Yes 2 screw terminals 6-8V my multi-meter says 11.5V this was with nothing on it (AKA plugged in no load)
If I wanted to get a newer one for safety (The Princess phone was left in the house only one though) Would a 6V one work?

Also how would it be wired? The second pair (Black/Yellow) where connected to it the other pair (Red/Green) were on the incoming terminal block.

This is all dead and the only phone is a cordless phone with multiple handsets and the main base unit is connected directly to the EMTA/Modem provided by Charter.
 
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Old 01-31-21, 08:55 AM
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Unlike LEDs, Princess phones with incandescent bulbs can slowly raise voltage until desired brightness. Would start at 12 volts.

Other types of phones are a different story.

For talk wires connect either/anyway. Then, if cannot break dial tone, reverse them.

Note when connecting some phones to office type phone systems there can be other issues.
 
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Old 01-31-21, 09:06 AM
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I would start with a 6v supply because unless it's regulated....it will be higher.
The adapter can be AC or DC.
 
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Old 01-31-21, 09:49 AM
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Open the phone a pull one of the lamps out. Most likely they are on sockets. The lamp voltage will be printed on the lamp somewhere. Most often it is on the metal base.
 
 

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