Help! How do I recognize the pinouts of a jack?

[sabzi]

Hello,
I'm a beginning student and I hope I am posting this in the right forum section. I need to find an audio jack to match the one in a schematic I have.
I have a schematic of a 3.5mm 3-conductor audio jack (shown below) and a photo of a 3.5mm 3-conductor audio jack (also shown below). Problem is I don't know which connection in the schematic corresponds to which connection in the photo. Could someone help me out?
Also, in the schematic, are pins 1 and 2 shorted together? If so, does this mean I could just use a 2-conductor jack?

Thank you,
Sabzi

 

[GSM Man]

The schematic isn't of a 3-conductor jack, but a 2-conductor jack with a switch.
Pin 3 is connected to the case - A
You can't tell from the picture which pins the other 2 are. However, it shouldn't be hard to figure out. When you insert a plug into the jack the 'tip' of the plug will contact pin 1.
Pins 1 and 2 act as a switch - shorted when no plug is inserted, open when a plug is inserted.

 

[sabzi]

Then does this mean that when the plug is inserted, pin 1 is open but pins 2 and 3 are shorted together?

 

[GSM Man]

No - the plug and jack "bodies" will be connected (pin 3). The 'tip" of the plug will be connected to pin 1, and pin 2 will not be connected to anything.