Power on when headphones are plugged in?

[SharpyWarpy]

Hi, all. Can anyone explain or point me to a tutorial that shows a circuit that will power on a cmoy headphone amp when the headphones are plugged in? Thanks ahead of time.

 

[SharpyWarpy]

some headphone sockets have build in switches
regards

Hmm, I've seen illustrations of phone jacks in the Mouser catalog with provision for disconnecting speakers when headphones are connected but none for power on/off.

 

[Juergen Knoop]

yes, my post was a little bit overhasty.
regards

 

[SharpyWarpy]

bump

 

[poynton]

Usually, the ground (sleeve) of the connector is used to switch either side of the battery depending on how the phones are conected)

Finding a switched 2.5 or 3.5mm socket may be the problem rather than how to connect it.

Andy

 

[SharpyWarpy]

Usually, the ground (sleeve) of the connector is used to switch either side of the battery depending on how the phones are conected)

Finding a switched 2.5 or 3.5mm socket may be the problem rather than how to connect it.

Andy

Thank you, poynton, for your reply.
The cmoy uses a virrual ground for the headphone return so using the jack sleeve isn't an option. The switched phone jacks available at Mouser, DigiKey, etc are designed to interrupt the output to speakers. I thought I could design a circuit to use that but, alas, all my attempts have been in vain. I tried a jfet/bipolar transistor combination with appropriate resistors but that didn't work. Promising, but didn't work, it just screwed up the sound. There was no DC offset, it just made it sound bad, which means I didn't get something right. So instead of pursuing that further I thought I'd see if anyone else had any ideas.

 

[Dan2]

what about a relay?

use a switched socket to drive the relay coil. (it will mean that u need voltage on all the time though)

but if u are close enough to plug the headphone in, surely it's nott too hard to flick a switch while you're there