Deciphering a DC jack schematic

Question

I am trying to include a DC jack on one of my PCBs. I am just setting up the footprints now, and I am not quite sure which pin is which. What do the symbols on the drawing mean?

I have included a snap of the schematic below, it has been taken directly from the datasheet.

Answer 1

Pin 3 is the center pin, pin one connects to the barrel and pin 2 is used to detect if there is a plug inserted. The lower left drawing shows the physical pins looking at the bottom side.

Answer 2

It's a visual representation of how the socket works.

• Pin 3 represents the pin that mates with the center of the plug (typically V+)
• Pin 1 is the sprung contact that connects to the outside of the plug (typically Gnd)
• Pin 2 contacts to Pin 1 (Gnd) but breaks contact when the plug is inserted (as the Pin 1 contact springs away)

Answer 3

While this is resurrected due to Endolith's retagging, I want to clarify the reason that Pin 2 connects to the shield of the jack, but only when there's no plug inserted. You can do one of three things to wire this correctly:

1. Only connect to pin 1.
2. Connect pins 1 and 2 together.
3. Connect pin 1 to your circuit's ground node, and connect pin 2 to another power connector (Black binding post for a banana jack, or battery ground terminal, for example.) Then, you can connect pin 3 to a red binding post or battery positive terminal, and have 2 power supplies without worrying about output contention.

Method 3 is the reason that these plugs are designed the way they are.

Answer 4

I generally connect pins 1 and 2 together.