Author Topic: 555 schematic?  (Read 565 times)

Offline RB

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555 schematic?
« on: May 02, 2017, 12:41:10 PM »
is there a complete schematic available for a 555 cord board?

unbeldi

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Re: 555 schematic?
« Reply #1 on: May 02, 2017, 01:04:26 PM »
Well, "complete" depends on what the installed features are and their dates.
For the basic standard board, the circuit drawings and circuit descriptions are available, yes, I am not sure about every circuit.


Here are some on my disk, that I could quickly find, but I am sure there are more somewhere.

Bell System Practices (BSP) Section 536-550-110 i1 520422 General Description; 555 PBX

GTE/General System Practices (GSP) Section 503-620-400 i1 6512 Description, Circuits; 555 PBX Switchboard

WECo CD 65715-01 Central Office Trunk Circuit
WECo SD 65715-01 Central Office Trunk Circuit
« Last Edit: May 02, 2017, 01:17:29 PM by unbeldi »

Offline RB

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Re: 555 schematic?
« Reply #2 on: May 02, 2017, 01:47:01 PM »
Thank you.
is there a way I can view them?

Victor Laszlo

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Re: 555 schematic?
« Reply #3 on: May 02, 2017, 03:09:34 PM »
Does your board have the circuit labels glued to the inside of the rear cover?

unbeldi

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Re: 555 schematic?
« Reply #4 on: May 02, 2017, 05:58:52 PM »
oh, the OP is our switchboard constructor.  He probably doesn't have a 555 himself.

Here are the practices I mentioned, they contain general information applicable to the generic 555 design.

Does your board have the circuit labels glued to the inside of the rear cover?

Offline RB

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Re: 555 schematic?
« Reply #5 on: May 03, 2017, 04:48:53 PM »
Thank you! much help.

Offline HarrySmith

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Re: 555 schematic?
« Reply #6 on: May 03, 2017, 06:38:52 PM »
I have a ton of 555 switchboard stuff saved on Google. I am not sure if you have to be signed in to see it but here is the link:

https://drive.google.com/drive/folders/0B6eDAxemj1VHZjk2NTgwNWItMGUzNy00YzhhLWI4NGQtNzc3MTU4OGE5MjRh
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Offline RB

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Re: 555 schematic?
« Reply #7 on: May 04, 2017, 01:35:01 PM »
Thank you unbeldi and Harry! lots of good stuff there.
The board is coming along well. Hope to give it the first spark test this weekend!