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My weekend endeavor

Started by RB, October 24, 2017, 08:56:48 AM

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RB

#15
I think you are right. it must be designed "short free".
I just can't see how it was done. The jacks appear to be almost the same, " the t and r contacts".
So when the plug is inserted, the tip=negative, contacts the ring=positive, and SHORT.
I need to think it through, and redesign my station jacks so they don't cause a short. I can do that :D
Since I started with nothing, I can do what ever I want...
I looked at my jack setup last nite.
What I found, is the station jacks, are designed just like the 1/4" parts I am using,
The difference...is in the length of the "tip" on the plug.
In Both styles, the tip of the plug, will momentarily bridge the Tip to the Ring of the jack when plugged in.
The pbx plug, has a shorter Tip portion than the 1/4" plug, and does not bridge the T and R of the jack.
Thats how they did it. Now, I have to redesign my jacks to circumvent this issue.
I think I just got another wrinkle in my brain! lol

Greg G.

And when you get that puppy up and running, if/when I get a switchboard, I'll be picking your brains!
The idea that a four-year degree is the only path to worthwhile knowledge is insane.
- Mike Row
e

RB

That may be a short trip Brinybay, lol, but happy to share  :)
I have spent a great deal of time reverse engineering circuits because I did not have much/any information, just the item.
And then building mock ups to be able to test them.
That is where my strength is.
I always got the thing to work on thrown in my lap...but not the info.
Come in to work in the morning to find something new on my desk...what is it???  it is yours, ...make it work.  ???

RB

#18
Yes, the Tip is shorter and cannot contact the T and R contacts at the same time.
Not like the 1/4" jacks, that short both momentarily.
I have reconstructed my station jack, see pic.
I now leave the jack dormant, until the relay locks on "manually", and switches power to the cord set.
It works slicker than puppy puick! no loud clicks, no shorts.!!! "short pause for a happy dance".
Gonna rewire the first two jacks this weekend to match the latest one, and that shud do it for this part of the project!
Last part will be the signal to the board for a requested call.