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Leich PBX L55 - will not ring out to a phone with a real bell.

Started by swreed68@gmail.com, October 15, 2021, 04:32:32 PM

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swreed68@gmail.com

Hello,

I am new to the group and would like to ask for some help on an issue I am having.

I have an Leich L55 10 cord board and I am running a Western Electric power unit SD-81824-01

I noticed that if I try to ring an extension where there is a telephone with an electronic ringer it will ring, but trying to ring a set with a real bell it will not.

I then checked at the jack with nothing plugged in and I have 120 VAC, but if a phone is plugged in it drops to about 25 VAC and doesn't ring the bell.  I have tried various sets with a real bell and they all behave the same.

The same behaviour is present on all ten cord sets.

If I measure ringing voltage at terminal 14 (which is the common ring feed to all cord sets) it does not drop off when ringing a phone with a real bell.  It looks identically solid at 120 VAC when ringing either an electronic ringer or a real bell.

Any ideals?  I have no other issues with the PBX but this.


Thanks in advance!


Sean Reed

RB

Hi Sean.
Welcome.
I do not know much about your board, but would like to ask a couple questions, and maybe suggest something.
First, does your board have a hand ringer?
It comes AFTER the bulb.
Have you tried ringing a bell that way?
What happened?
Next, there really isn't a lot to that circuit.
I suspect someone has possibly installed a lite bulb in the gen circuit that is incorrect for that board.
You mentioned, ringing an electronic bell works?
That will not require as much current as a coil bell.
You also mentioned, that measuring the voltage BEFORE the circuit, produces proper output from power supply,
And measuring AFTER the bulb, power drops drastically?
That also could happen, if a too large bulb was installed.
Maybe try bypassing the bulb for a quick test?
The last think I can think of, is possibly burned or very dirty contacts on the RING button???
Try cleaning the contacts, that may help???

5415551212

Sounds like a interesting setup.
Post some photos if you can.

swreed68@gmail.com

Quote from: RB on October 16, 2021, 03:27:09 AM
Hi Sean.
Welcome.
I do not know much about your board, but would like to ask a couple questions, and maybe suggest something.
First, does your board have a hand ringer?
It comes AFTER the bulb.
Have you tried ringing a bell that way?
What happened?
Next, there really isn't a lot to that circuit.
I suspect someone has possibly installed a lite bulb in the gen circuit that is incorrect for that board.
You mentioned, ringing an electronic bell works?
That will not require as much current as a coil bell.
You also mentioned, that measuring the voltage BEFORE the circuit, produces proper output from power supply,
And measuring AFTER the bulb, power drops drastically?
That also could happen, if a too large bulb was installed.
Maybe try bypassing the bulb for a quick test?
The last think I can think of, is possibly burned or very dirty contacts on the RING button???
Try cleaning the contacts, that may help???


Thanks for the reply.  It doesn't have a hand crank gen.

Voltage stays the same both sides of the bulb, and bypassing the bulb still gives no ring.

The drop is on cord - and all ten cord sets behave the same.

RB

I guess I am confused about this statement...

"I then checked at the jack with nothing plugged in and I have 120 VAC, but if a phone is plugged in it drops to about 25 VAC and doesn't ring the bell.  I have tried various sets with a real bell and they all behave the same."

What exactly are you referring to as the "jack"???
There should not be more than the TALK voltage on the jack, 24 or 48 volts, "with the phone on the hook". until a cord is plugged into the jack for that extension, and the RING button is pressed.
Could you post a couple pics of your board, and your procedure?
Regards

FABphones

A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
***********
Vintage Phones - 10% man made, 90% Tribble
*************

swreed68@gmail.com

I was using an improper term - meaning where a telephone set was plugged into.


< edit 10-20-21 : image removed, rotated, reinserted >

swreed68@gmail.com

The overall unit.


< edit 10-20-21 : image removed, rotated, reinserted >

RB

OK, that is a Leich board. not sure of the actual model, there are several.
I assume that jack is connected to one of the terminal strips on the back??? as an extension.
I still do not believe there should be 120 volts present until the ring signal is sent. however.
do you have the actual model number of your board?
I would like to know and see the schematic for that one.
That would tell more about it's purpose.
And could you post a pic of the terminal strips on the back showing the power connections as well as the extension connections.
That may help in understanding the situation.
Regards

rdelius

The Leich L55 is an almost exact copy of a  WE 555 board. schematics mite interchange. I have wired both .Have you tried another power supply or connected the ringer directly across the output of the power supply? .

5415551212

Quote from: rdelius on October 20, 2021, 08:55:01 AM
Have you tried another power supply or connected the ringer directly across the output of the power supply? .
This ^^^^
Defiantly connect a phone directly to the ringing power supply.
I think the resistance lamp should drop the voltage 15 volts or so, perhaps the schematics you have specify an ohm value for that lamp?

swreed68@gmail.com

Sorry it's been a couple of days since I had time to work on it.  I tried the phone directly across the ring terminals of the power supply and it rang as expected.

swreed68@gmail.com

Quote from: RB on October 19, 2021, 10:48:47 PM
OK, that is a Leich board. not sure of the actual model, there are several.
I assume that jack is connected to one of the terminal strips on the back??? as an extension.
I still do not believe there should be 120 volts present until the ring signal is sent. however.
do you have the actual model number of your board?
I would like to know and see the schematic for that one.
That would tell more about it's purpose.
And could you post a pic of the terminal strips on the back showing the power connections as well as the extension connections.
That may help in understanding the situation.
Regards



Yes, the jack where the phone plugs in is connected to a terminal on the back as an extension and works well for talking etc.

Let me get a pic of my connections

swreed68@gmail.com

Here are some shots of the terminal board