7805 Power Draw (using PSOne screen)?

[segasonicfan]

does anyone know how much power the 7805 circuit uses? More specifically, drawing a 500mah load like the two in the PSOne screen. I'm powering my screen off 7.5v and 5v indivually in hopes to extend the battery life but I need to know if it's actually worth the trouble. I'm hoping they use up a acouple watts. There's another 5v regulator in there too (a much smaller one) that I'm taking out as well.

Anyone know?

[usbcd36]

A 7805 uses about 50-100mA (given off as heat), not enough to worry about. Don't bother with them, and put BOTH of them back on the screen. Another option would be to use 2 switching regulators in place of the 7805s, but that is costly and space-consuming. The advantage to this is they are very efficent and don't need heatsinks. Don't bother with the two power sources, one set of batteries will always run out faster than another (unless you get REALLY lucky or are a math genius) and you'll be stuck with something that halfway doesn't work. It will not add much more time than using switching regulators and extra batteries in parallel and is just plain cumbersome.

[segasonicfan]

Thanks for the info I'm not planning on using two batteries at all...I was just thinking of a way to reduce the power consumption on my PSTwo Portable since the PSTwo already has 2 7805s inside it I could take all 4 out and replace it all with once nice high current 7805 reg. It might be worth it if they're using up 100mah...that's nearly 3W of power being wasted. hrmm

-Segasonicfan

[usbcd36]

Except it would generate a tremendous amount of heat because all of the heat released would be in one place.

[segasonicfan]

yes but I've already installed an extra fan and there is a perfect place for the chip next to the vent.

-Segasonicfan