I think that a pc's RS232 could be used as power source, since we have 3-15V high output and same as negative, across a pc constant power could be supplied to a load over RS232

further information about this text doesn't exist right now, if there is any barrier just tell me, otherwise i will try to do it in few months.

 

Only constraint is that you will not be able to drive large loads. You can drive LEDs or solid state relays also, but not many. What are results of your trial?

Regards,

C. Potdar