using iPhone/iPod touch audio jack as power output

hi guy:
I am working on a project that requires using softmodem to communicate with iPhone through audio jack. The way we deal with it is using Softmodem Terminal which is made by ARM22 on iPhone to see if the result is correct.

When I use external power as power supply, everything goes well. However I need to use the audio jack as power output to make sure there is no external power require. I have tried using schottky bridge rectifier with 10uF capacitor to optimise the output. I wonder if there is any other way I can get the power through phone jack with SoftModemTerminal?

softmodem Terminal
Softmodem Terminal

The audio jack does not output power as far as I know. If it was outputting a signal you may be able to use parasitic power but I doubt that as input, there would be power available.