RCA plug detect

[pree]

Hi,
I have an application, where the device has a RCA IN and RCA out jack. In the HW I have RCA signal detection implementation.
However, I would like to add RCA plug detection.
Is there any way apart from special RCA jack which has the pin to detect the RCA Plug in or plug out detection.

[Terry Bites]

Extend the plunger or add a rod to the arm of a microswitch?
The things they use on mobile phones maybe
 eg Hd-11 turtle switch 4 * 5.6 silent turtle reset switch

[CatalinaWOW]

Hi,
I have an application, where the device has a RCA IN and RCA out jack. In the HW I have RCA signal detection implementation.
However, I would like to add RCA plug detection.
Is there any way apart from special RCA jack which has the pin to detect the RCA Plug in or plug out detection.

I am not sure I understand the question.  Are you asking if there is a way to determine if the plug is installed in the jack, or if there is a way to determine whether the plugs are installed in the correct jacks?  In either case sensing the impedance would probably work, with slightly different implementations depending on which question you are asking.   Perhaps you could do both.

[pree]

I want to know, if the plug is installed in the jack. I do not want, if the plug is installed correctly or not. I want to know how can i determine that the plug is installed or not.

[CatalinaWOW]

So two cases:

1.  A plug is in one of your jacks and the other end of the cable is in some other piece of gear.  You know the resistance to ground of your equipment (often in audio gear inputs it is 47k ohms).  You can make that one leg of a voltage divider and look for a voltage change from the resistance to ground of the connected device.  The reference is the voltage when no plug is in the jack.

2. A plug is in one of your jacks and the other end of the cable is not connected.  This is harder but not impossible.  Assume that the cable is of some non negligible length and measure the capacitance of the cable added to the existing capacitance parallel to your devices plug.  The larger your devices capacitance the more difficult this will be. 

There are many variations on these themes.

[pree]

thanks,
the equipment in my case is a hub and other end of the RCA cable is in the speaker. So, you mean the resistance to ground of my hub?
Do you have some diagram to explain the connection.

[CatalinaWOW]

Rather than draw a circuit I will describe an extreme case.  Once you understand the concept you can easily come up with easier, more appropriate implementations.  In your hub put a normally closed relay in series with the output.  On the output side of the relay put a moderately high value resistor connected to your positive supply.  The resistor will have negligible impact when the relay is in its normally closed position.  When you want to check connection, say as part of the powering up sequence, you briefly open the relay.  With the relay open, if the speaker is connected the less than twenty ohm resistance of the speaker will pull the voltage near ground.  If not it will be at the supply voltage.