Is it possible to draw power from spare PCI-E slot ?

I've done some searching and come up with nothing which makes me think it's not possible. But, there are some very sharp members on this forum that may know different.

I know bits, nibbles & bytes better than volts, watts & amps.

Question: If I have a spare (empty) PCI-E slot on my MP is there any type of adapter card I could pop in the slot that would give me another 6-pin 75 watt PCI-E power connection?

Thanks.....