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I need to change a DC jack to a different one (with long bushing).

I'm not to sure which terminal connector is what from the manufacturer's diagram.

The DC jack is a L712A from Switchcraft (Manufacturer Ref)

And this is the diagram they provide: http://www.switchcraft.com/Drawings/L712A_cd.pdf

How do I tell which one is which?

Edit: Here's a photo of the jack if that's any help:

Edit 2: Photo of the other side

Ben
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2 Answers2

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enter image description here

The sleeve shunt will disconnect from the sleeve when you insert a connector. At the bottom of the drawing they make contact. When you insert a connector that will connect to the lower contact. If you follow that to the right and up you see that it has its soldering tab at the top.

Typical use of the sleeve shunt is to connect it via a pull-up connector to V+. If the plug isn't inserted the voltage level at the sleeve shunt will be ground, with the plug inserted it will be V+.

edit
You can also test it by inserting a connector carrying a voltage. You'll measure the voltage between the central pin and the sleeve tab, but nothing between center pin and sleeve shunt.

stevenvh
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  • How do you tell it's connected to the top tab? – Ben May 06 '12 at 10:53
  • Is the shunt the longer bit at the bottom (with the hook) or the smaller bit above it that touches it? – Ben May 06 '12 at 10:54
  • Experience with reading mechanical drawings helps. When you follow the shunt (the longer bit with the hook, the hook will make the contact with the connector's sleeve) to the right it bends to follow the housing, and at the top it reappears at exactly the same horizontal position. – stevenvh May 06 '12 at 10:57
  • right, makes sense, so in relation to the *2nd photo*, the shunt connector is the one in back (with the bit following the housing visible at the front), right? – Ben May 06 '12 at 10:59
  • "Experience with reading mechanical drawings helps." Wise words :) – Ben May 06 '12 at 11:00
  • Yes, on the second photo you can see the hook at the bottom left. That hook is the contact for your connector's sleeve. – stevenvh May 06 '12 at 11:01
  • You're entirely welcome! :-) Glad to be of help. – stevenvh May 06 '12 at 11:08
  • II would call the red terminal in your drawing the sleeve contact. The sleeve shunt or switch contact would be the smaller part touching the sleeve contact near the hook, but I can't tell from the photos which terminal that part connects to - I'd use an ohmmeter to verify which terminal is which function. – Peter Bennett Feb 10 '21 at 21:59
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What is written above is confusing dialog. "The hook is the contact for your connector's sleeve." This is the last statement from stevenvh. This is correct.

But, stevenvh also says "When you follow the shunt (the longer bit with the hook, the hook will make the contact with the connector's sleeve) to the right it bends to follow the housing, and at the top it reappears at exactly the same horizontal position. The shunt is NOT the longer bit with the hook!

In the drawing shown the sleeve contact is at the top. The sleeve is the receptacle connector part with the hook with the sleeve of an inserted power cable end connector making contact at the hook. The connector part with the hook then continues to the right and bends up to follow the connector housing.

The shunt contact is shown at the front of the drawing, with the center pin contact is shown at the back.

The shunt breaks connection with the sleeve when a mating connector is inserted. This happens because the sleeve on the inserted cable end connector contacts and compresses the hook, pushing it away from and disconnecting it from the small shunt part inside the receptacle connector.

SKB
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