What Else Used 6-8V AC?

[MIPS]

Sorry, it's a bit of a vague question to ask but for christmas I opted to charm the local makerspace by debugging the original telephone wiring that was installed back in the 60's when their building was converted into a hostel.

There are six pairs coming into the basement panel from the pole and terminating at a 66 block. From there two 10 pair cables run to each of the two floors of the building, with the first floor terminating at a 50 pin centronics plug with another 66 block attached to it and upstairs to another 66 block hiding in a hallway closet. Beyond that the wiring has long been ripped out or repurposed to the point I had no choice but to rip it out anyways just to leave me with everything but blocks and trunk wiring. That all seems pretty standard if the first floor termination was where the first floor was wired to and had the phone system installed (no idea what used to be there) and upstairs was all patched together using the block in the basement where necessary.
What is getting me confused though is that in the basement there is a Northern Electric 6-8v AC wall wart plugged in and terminating on the block in such a way that both the first and second floors have power available on two pairs of wires. My lack of knowledge say that only a Princess would of used that but this wasn't a residential building. Likewise my guess was a simple key system like the 1A2 was self powered so I am not sure what might of needed that extra power.

Edit: Adding pics.

[rdelius]

possible intercom or buzzer  system

[robert_m]

Many Buzzers on 1a2 used 8v for signaling.  SE-8 & KS20419

[Key2871]

Well someone tried to make it look nice, but that's not Bell's way of wiring. An old fuse breaker box with a block and CPs in inside. I've seen worse, that's for sure.
I'd say signalling as well. Not a bad idea as far as how things are laid out..

[MIPS]

Actually, that's an official BC Tel cabinet. Hard to see in the below photo but the branding is stamped just above the handle.

[dsk]

Where I grew up the doorbells was supplied by 8V from a transformer serving 21 apartments.

dsk

[robert_m]

KEY2871 - Ameritech / Ill Bell wired many 1a2 like that and that appers to be a real bell cabinet.

[Key2871]

BC tel, well thanks for clearing that up.

[poplar1]

Many Buzzers on 1a2 used 8v for signaling.  SE-8 & KS20419

Western Electric used KS-20419 Buzzers in multi-line sets in the 70s and 80s. These are rated at 10 VAC.

WE 1A2 KSUs (Key Service Unit) typically used these voltages, IIRC:

Lamps 10 VAC
Interrupter 10 VAC
B Battery (for relays in the 400-type KTUs) = 24 VDC
A Battery (for intercom talk path)= 24 VDC filtered
Common audible signaling:  90-105 VAC 30 HZ for ringers *OR*  10 VAC for KS-20419 buzzers
Intercom signaling: 10 VAC for KS-20419 buzzers *OR*  90-105 VAC 30 HZ for ringers

Older power supplies produced 20 HZ for ringers. Edwards buzzers mounted in 564s required 18 VAC.

[robert_m]

Yeap, but that transformer pictured actuall would run the buzzer, and also think if i recall its the same one used for the princess light, id have to check again as i already posted what a signature or old one used.

[MIPS]

The transformer is a 2012A, rebranded the N.E.2012A.

[Jim Stettler]

BC tel, well thanks for clearing that up.

I have seen the same style of box marked Western Electric and also with Bell System stickers.
The emblem was the '39 bell. This style  were in use before 66 blocks.
Jim