thanks for the input.
Thanks all, I was hoping to get feedback.
EDIT: ok the first part has some erors but I thought it might be usefull to people in seeing where I was going wrong, if not let me know and I'll delete it.
I understand that changing the resistance(pencil mod) increases the voltage being produced by the votage regulator. My understanding is that by shading the resistor current is being added, a path is being created around the resistor (which restricts current) to allow more current to reach the voltage regulator thus increasing the output voltage of the regulator. I also understand that the versions of the particular card I want to apply this too has some diifferneces from it's big brother (mine 8600GT => big bro 8600gts). The 8600gts has faster clock speeds and an added 6 pin pci-e power connector. So that tells me that if my 8600gt will reach 8600gts speeds it will most likely require 8600gts power levels aswell. I realize people are making this mod work by taking the excess power the card requires from the motherboard(pci-e motherboard slot), done by shading the resistor, using conductive ink/paint and adding resistors or trim pots.
Some people are able to add the 6 pin connector to the card (some pcb's have the 6 pins configured so a connector just needs to be added),and just plug it in for the power(so I've read). If adding the 6 pin connector eliminates the need for the other types of volt mods, but isn't an option with a particular card, wouldn't a cross between the mods work aswell. As long as the power I add is complimentary to the power already flowing through the circuit, why would it matter where it comes from as long as the card gets the power it requires. I'm talking about making the same adjustments that everyone else is doing, just looking for another way to do it. Taking the power from the motherboard can be done, it has been done, but I understand it's not the greatest thing to do. I'm just considering options. Yes the circuit I'm talking about is more complex, but it's the end results I'm interested in, the functionality. Do I need it, no. I could go buy another graphics card, that would be the simplist. From what I've read, changing the voltage while the card is in operation hasn't been done yet or is constantly advised against(I'm sure it's been played with though).
Seems like a nice option for someone who wants to oc with voltage increases but doesn't want a perminantly active mod. Trim pots work great for adjusting resistance, and stepless adjustments have their benefits. However, in this situation I think stepped adjusments would work a little better for reducing adverse effects of voltage increase. It seems to me that the smaller the increment the less chance of adverse effects. I know 5 min turning a dial or 5 min pushing a button 100 times... I like buttons better than dials
I need to understand how the voltage regulator works, I think thats where this idea is going wrong. (virgin remember) The feed back pin is where I went wrong. It dosn't feed the volt reg it's power, it sets the level of output. (thanks Frank & Largon)
So adding power isn't wrong, I was just thinking the wrong spot.
Can no one see the benifits of a circuit like this?
How the resistance is adjusted isn't the important part( the tac and ic is just my twist and finding the safe stable method is a given), the main focus would be giving the card the optional extra power from a safe source with the ability to make adjustments (or disable the mod) while the computer is running. Obviously the voltage display is fluff, but hey, it can't hurt right