Author Topic: Panasonic PBX Power Supply Modification  (Read 5122 times)

Offline trainman

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Panasonic PBX Power Supply Modification
« on: March 27, 2011, 01:04:56 PM »
Hi All, I  wanted to use the Pnsonic PBX simply to connect two phones together in-house, but not to an outside line.

I don't want the pbx powered up 24 hrs. I was rhinking of some kind of relay to turn the unit on when you pick up one phones receiver. So, I was wondering, if there was  contact on the hookswitch that could make when picked up to power a rely coil, to turn on the unit.

I don't know if it would work, because first, I hve no idea what voltages and currents the phones work from. THen finding a proper coil. THen, there is power requirement of the relay coil, and there simply may not be enough of it on  long run of wire to operate the relay coil.


Any thoughts? Godd idea or bad?

Offline Owain

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Re: Panasonic PBX Power Supply Modification
« Reply #1 on: March 27, 2011, 01:39:21 PM »
You could do this, but you would have to modify the telephones (I presume you're using standard phones) to bring out hookswitch contacts, use either a mains power supply or a battery as power supply to a relay to switch the mains.

Then you'd have to wait for the Panny to go through intialisation and set-up every time.

If you just want a ring-down circuit for an intercom then use that.

Offline gpo706

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Re: Panasonic PBX Power Supply Modification
« Reply #2 on: March 27, 2011, 02:10:59 PM »
Just leave the Pana on, its by far the easiest solution.
"now this should take five minutes, where's me screwdriver went now..?"

Offline trainman

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Re: Panasonic PBX Power Supply Modification
« Reply #3 on: March 27, 2011, 02:12:59 PM »
I forgot about power to the rely coil. Then I thought bout mounting a small microswitch or simmilar to act when the hookswitch is raised or lowered. But I would to find a smll current draw relay coil because dry-cell power supply would be easist.

I didn't want to lweave it on all times because it would see little use, and i figure it would extend the life of the unit.

Offline Owain

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Re: Panasonic PBX Power Supply Modification
« Reply #4 on: March 27, 2011, 03:59:19 PM »


I didn't want to lweave it on all times because it would see little use, and i figure it would extend the life of the unit.

Voltage surges at switch-on are more likely to shorten the life of the unit.

Offline Phonesrfun

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Re: Panasonic PBX Power Supply Modification
« Reply #5 on: March 27, 2011, 06:54:28 PM »
Owain has a definite point about the power surges.  He also has a point about it not being instantaneous in coming on.  It probably goes through about a 15-second boot-up sequence.  Best to just leave it on.  It sure does not take any appreciable power.  Mine is on 24/7 and I must say that I surely cannot see a difference in my power bill.

-Bill G

Offline bingster

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Re: Panasonic PBX Power Supply Modification
« Reply #6 on: March 27, 2011, 11:55:32 PM »
Try keeping an eye out for one of these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180641585154

That particular one is outrageously priced, but I got mine for around $25.  It's perfect for quick and easy point to point calling using any two standard telephones, and is also very handy for testing purposes.
= DARRIN =



Offline Brinybay

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Re: Panasonic PBX Power Supply Modification
« Reply #7 on: March 28, 2011, 01:17:45 AM »
Not sure I'm getting this.  Why don't you want to leave the power on?  I have a Panasonic 308.  To reach another extension, I just dial the extension.  That will work with or w/o a line going in.  But the power does have to be on.
The idea that a four-year degree is the only path to worthwhile knowledge is insane.
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e

Offline trainman

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Re: Panasonic PBX Power Supply Modification
« Reply #8 on: March 28, 2011, 01:42:51 AM »
i didn't want the power on all times because unit would be used infrequently, and I thought it would prolong the life of the unit by not keeping it powered up at all times.

I don't think it would be used enough to justifiy it being on at all times.

It's only a novel way to call my downstairs  flat neighbor(cousin), and be able to dial the rotary phones,  but we're only home at the same time on weekends, hence the infrequent use.

Offline Owain

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Re: Panasonic PBX Power Supply Modification
« Reply #9 on: March 28, 2011, 07:21:53 AM »

It's only a novel way to call my downstairs  flat neighbor(cousin), and be able to dial the rotary phones,  but we're only home at the same time on weekends, hence the infrequent use.

If you really want to, use a 7-day timer on the mains supply and set it for weekends only.

Offline GG

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Re: Panasonic PBX Power Supply Modification
« Reply #10 on: March 28, 2011, 08:22:08 AM »


Power consumption on these is relatively low and would only be a serious concern if you're on off-grid power (solar).  I tested all of them with a Kill-A-Watt meter a while back and found that the lowest power consumption of any of them was the KX-TD 308, a relatively obscure model that didn't sell a whole lot and came equipped for 4 extensions expandable to 8.  I have one and I'm not planning to sell it, as I might be off grid at some point. 

However, for sheer energy efficiency and minimum eco impacts, for an intercom system among two to five stations, nothing beats a good ol' magneto phone system.  Use coded ringing for any more than two stations.  Power the phones' transmitters with two D batteries in series.  Use rechargeable batteries, keep some charged ones on hand for replacing discharged ones when needed.  Get a solar charger if you want to go that far, but otherwise, a conventional charger for those will still use relatively minimal power.   (This is better than powering the transmitters with AC adaptors, which will always be drawing some mains power even when the phones are not in use.) 

Used as an intercom system that way, with more than two stations, you'll need to have the number labels printed with the ringing codes, e.g. "Answer 1 long ringn + 1 short ring" and "Answer 2 short rings," etc.  Just as it was back in the day of heavily loaded rural party lines. 

Offline gpo706

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Re: Panasonic PBX Power Supply Modification
« Reply #11 on: March 28, 2011, 08:29:23 AM »
Try keeping an eye out for one of these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180641585154

That particular one is outrageously priced, but I got mine for around $25.  It's perfect for quick and easy point to point calling using any two standard telephones, and is also very handy for testing purposes.

Thats a neat gadget, but not nearly as fun as Panasonic!  :)
"now this should take five minutes, where's me screwdriver went now..?"

Offline Wallphone

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Re: Panasonic PBX Power Supply Modification
« Reply #12 on: March 28, 2011, 09:17:54 AM »
The Micro Seven is a product similar to what Bingster posted, > http://bit.ly/idIsEv < and comes in 2 and 4 line models. Be patient and you can get one for around $30, and there is a manual for it Online.
Doug Pav

Offline trainman

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Re: Panasonic PBX Power Supply Modification
« Reply #13 on: March 28, 2011, 11:48:05 AM »
I don't have any magneto phones. THose would be more fun, I suppose.

Can one wire 500 type phones to work from battery?  WHat's the lowest voltage they will will recevie/talk on?

Offline Owain

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Re: Panasonic PBX Power Supply Modification
« Reply #14 on: March 28, 2011, 12:14:27 PM »
I don't have any magneto phones. THose would be more fun, I suppose.

Can one wire 500 type phones to work from battery?  WHat's the lowest voltage they will will recevie/talk on?

circuit here