atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems WECO 551B Ringers and Buzzers???

Hi everyone!

I just scored my second WECO 551B KSU with a 118a Frequency generator. My question is, any way to wire up a switch or a relay at the KSU to select ether ringing with the 118a Frequency generator or just buzzers for incoming calls. If so, what modifications would I have to make to the wiring at the block. I would like to have the option to switch to ether ringing or buzzing for incoming calls.

Personally I like the sound of the buzzers when a call comes in but I do not want to have the 118a Frequency generator to go to waste...... especially since it has the rare bracket...


I would appreciate any ideas and feedback.




Thanks

If you wire 10 or 18VAc to the RB/RG leads (where your 118 is wired) and put buzzers in the phone and connect that pair to the RG/RC leads, you'll get buzzers buzzing on incoming ring.

A relay or switch could switch the proper ringing current onto the RB/RG leads while simultaneously switching the buzzer/ringer pairs onto RG/RC.

Sam

I made such switch on my 551C. But I use ringing generator with DC12V supply (from lamp/buzzer AC10V via a rectifier). So in my case it is just switching 1 contact to where the AC10V should come: to buzzers loop or to feed the ringing generator. I wired this switch to a control relay in the PBX, so I can switch buzzers to ringers and back remotely from any station by dialing the relay switch code. Alternatively it can even be controlled automatically via timer. But I do not need such.

very cool!

hey RedBul ,

Would you mind posting some pics or a video of this setup, I would love to see it.

Hi, I believe I’ve published it here couple of years ago, when I made the assembly of that KSU. But the old photos disappear somehow from the image hosting. I will make new and place the here.

Here you are!

For this KSU I’ve built a small “option module” which contains 12V powered ring generator and a simple power supply for it:


Power supply is just a diode bridge rectifier coupled with filter capacitor and a control light bulb. Because it takes power from the same 10V AC lamp source as buzzers, it is easy to switch between buzzers and ringer: simple 2 positions relay to either supply 10V AC to the ringer generator or directly to the buzzers pair to the telephone cabling:


Also a safety 300 Ohm resistor is added in series with ringing output - it is not obligatory, but recommended to protect the ringer generator from short circuit on the ringer pair in the floor cabling.

There are no modifications done to this KSU itself with this option. The whole board is fixed using 1 screw through the standard ring generator mounting bracket hole and connected to the non-modified 66 block of 551C KSU with regular wires.

So far based on 2-3 years of using this system it proved to be reliable and the ringer generator is sufficient to power 4-5 phones at minimum, which is enough for most applications of 551-type KSUs. I have one ringing phone per floor in my house which is more than enough when it rings. There is also a plan to connect a central ringer (Western Electric “Chime” ringer) on the same pair to announce the call on the staircase.

Overall view of the system:

I think I would have found a better place to put that so it doesn't cover the block.

-Hal

Thanks for critics, but I do not touch that part of 66 block ever since I’ve punched down the incoming lines and ringers/buzzers. It is rather a question of cosmetic or aesthetic considerations - or personal taste. Even if I need access to the entire 66 block it is only one screw to loose and then the whole thing can be turned up or down, opening access to all rows of contacts.

But for sure you can find an alternative place as well. E.g. each 551C KSU has a provision for a fifth 400-type line card just missing the card connector and wiring (horizontal slot below the four vertical slots for KTUs and above the interruptor). I suspect there was a plan at Bell Labs to furnish 551C with 5-lines capabilities, however it was abandoned due to not enough space on the 66 block and the use of liquid Mercury contact relay in the later 400-type line cards, which should be only installed vertically.

In principle, anyone can add the 400-type line card connector there and wire it to a small extra 66-type block. Alternatively this ringer card can be cut to fit that slot.

Because I considered adding the fifth line to this KSU (before acquiring 584C panels and Call Director sets), I didn’t bother to look for another place for the ringer option. Now this is not needed on that KSU.

How about in a box external to the KSU?

-Hal