555 won't ring stations

[BruceP]

Hi all,

New to the group after buying a WeCo 555 last weekend.
I have a power supply with 24 VDC and 20 HZ A/C ring output.
From this forum, I found where to attach them.

I can get everything to work, except ringing a station from the board.
I plug in, press the button, and the phone does not ring.
(Tried with 3 phones on 2 different lines)
I can dial out & take incoming calls (from my Vonage box).
I can patch them through to stations & talk & hear.
If I set up an unattended connection between my trunk & a station & call it, the phone rings.
But it won't ring when I try from the board.
I measured the AC supply and it shows 20 Hz and ~ 105 volts.

Any suggestions?

[K1WI]

Hi, This might be a real long shot , but I remember vaguely    that some versions had a pair of resistance lamps in series with BOTH sides of ringing voltage. They look lime a cross between a light bulb and a vacuum tube , usually with just two leads.   .........BUT it has been a long long time since I've even seen a 555.
    Good luck ,
                                  Andy F   (K1WI/HI)

[DavePEI]

Hi, This might be a real long shot , but I remember vaguely    that some versions had a pair of resistance lamps in series with BOTH sides of ringing voltage. They look lime a cross between a light bulb and a vacuum tube , usually with just two leads.   .........BUT it has been a long long time since I've even seen a 555.
   Good luck ,
                                 Andy F   (K1WI/HI)

Not two, but one, Andy. It has a screw base, and is located on the left hand back side of the board. If it is bad, you can replace it temporarily with a low wattage refrigerator bulb. Make sure your BATT switch is turned on.

Dave

[BruceP]

I do see one vaccuum tube looking thing near the bottom of the chassis. And the schematic shows a "12L" lamp on the +/- lead. So if this is blown the current won't run. Thanks!
Any idea where to get a replacement?

[DavePEI]

I do see one vaccuum tube looking thing near the bottom of the chassis. And the schematic shows a "12L" lamp on the +/- lead. So if this is blown the current won't run. Thanks!
Any idea where to get a replacement?

As I mentioned above, you can temporarily use a low wattage refrigerator bulb. Replacements are available from other collectors but are getting scarce.

Dave

[BruceP]

The bulb filaments look good, about 46 ohms. Tried a 40W fridge bulb, about 26 ohms, same results.
With the power on, and the bulb removed, I get 111.8 V 29.98 Hz at supply to board, and 66.6 V 29.98 Hz at bulb (?) With the bulb in, I get 0 V.

I do get power at the buzzer, which I can adjust with the front dial.

Trying to figure out the schematic, and those 348A plugs...

[BruceP]

I just noticed this power supply only puts out 0.05 Ringing amps.It is a "Key System Power Supply".
How much do the correct ones put out?

[DavePEI]

I just noticed this power supply only puts out 0.05 Ringing amps.It is a "Key System Power Supply".
How much do the correct ones put out?

My QGG1A which provides ring voltage to my 555 also outputs .05 amps - no problem ringing phones. Sounds like you might have a short circuit in the ringing circuit somewhere on  the far side of the resistance bulb.

Dave

[poplar1]

Many people use key system power supplies such as the WE 101G with a 555 PBX. Do you have the PBX grounded?

[BruceP]

Yes its grounded. When I first took the bulb out, there was some old tissue stuffed in there which I pulled out. Maybe it was a fix for the short

[G-Man]

Since you indicate the ballast lamp is in good order I would immediately put it back into service since there seems to another problem elsewhere.

Using a refrigerator or other household lamp does not provide any protection and your ringing supply could end up damaged beyond repair if you accidently short it out while troubleshooting the symptoms.

[DavePEI]

Since you indicate the ballast lamp is in good order I would immediately put it back into service since there seems to another problem elsewhere.

Using a refrigerator or other household lamp does not provide any protection and your ringing supply could end up damaged beyond repair if you accidently short it out while troubleshooting the symptoms.

I did say "Temporary". As he found the tissue in there, it is highly doubtful that the resistance bulb was making contact with the socket, so until he discovered the tissue and removed it, the resistance bulb was basically out of circuit.

Dave

[G-Man]

If there is a short or heavy ringing load the ballast lamp will glow with the brightness varying, depending on how much current is passing through it, so if ringing is not being applied you will not see a glow.

Often ringing one or two stations may not cause it to be visible either.

Since you stated that the night alarm buzzer is working that would indicate ringing voltage is being applied internally since the buzzer uses standard 302 type ringer coils working off of the ringing supply.

Are the sets that you using wired for bridged ringing?

[G-Man]

It's doubtful that the tissue prevented the ballast lamp from making contact since the attendant's night alarm was sounding.

Also bypassing the ballast lamp without removing a short or providing alternative protection is risky since with most key system ringing supplies you will hear a "Pop" and perhaps smell a bit of smoke, indicating the coil has "blown."

[DavePEI]

It's doubtful that the tissue prevented the ballast lamp from making contact since the attendant's night alarm was sounding.

Also bypassing the ballast lamp without removing a short or providing alternative protection is risky since with most key system ringing supplies you will hear a "Pop" and perhaps smell a bit of smoke, indicating the coil has "blown."

Guess that's why Northern Electric Service bulletin T162TB suggests using a low wattage fridge bulb for temporary replacement if you don't have the correct resistance bulb. They are fine for temporary testing.

Must also explain the reason most ringing supplies are FUSED on the output!

I do agree that it appears there is a good possibility the phones he tried aren't set up for private line (bridged ringing).

Dave