Random Thoughts.....What Are You Thinking?

Electrical engineering

Some electronic components develop lower resistances or lower triggering voltages (for nonlinear resistances) as their internal temperature increases. If circuit conditions cause markedly increased current flow in these situations, increased power dissipation may raise the temperature further by Joule heating. A vicious circle or positive feedback effect of thermal runaway can cause failure, sometimes in a spectacular fashion (e.g. electrical explosion or fire). To prevent these hazards, well-designed electronic systems typically incorporate current limiting protection, such as thermal fuses, circuit breakers, or PTC current limiters.

To handle larger currents, circuit designers may connect multiple lower-capacity devices (e.g. transistors, diodes, or MOVs) in parallel. This technique can work well, but is susceptible to a phenomenon called current hogging, in which the current is not shared equally across all devices. Typically, one device may have a slightly lower resistance, and thus draws more current, heating it more than its sibling devices, causing its resistance to drop further. The electrical load ends up funneling into a single device, which then rapidly fails. Thus, an array of devices may end up no more robust than its weakest component.

The current-hogging effect can be reduced by carefully matching the characteristics of each paralleled device, or by using other design techniques to balance the electrical load. However, maintaining load balance under extreme conditions may not be straightforward. Devices with an intrinsic positive temperature coefficient (PTC) of electrical resistance are less prone to current hogging, but thermal runaway can still occur because of poor heat sinking or other problems.

Many electronic circuits contain special provisions to prevent thermal runaway. This is most often seen in transistor biasing arrangements for high-power output stages. However when equipment is used above its designed ambient temperature, thermal runaway can still occur in some cases. This occasionally causes equipment failures in hot environments, or when air cooling vents are blocked.
Semiconductors

Silicon shows a peculiar profile, in that its electrical resistance increases with temperature up to about 160 °C, then starts decreasing, and drops further when the melting point is reached. This can lead to thermal runaway phenomena within internal regions of the semiconductor junction; the resistance decreases in the regions which become heated above this threshold, allowing more current to flow through the overheated regions, in turn causing yet more heating in comparison with the surrounding regions, which leads to further temperature increase and resistance decrease. This leads to the phenomenon of current crowding and formation of current filaments (similar to current hogging, but within a single device), and is one of the underlying causes of many semiconductor junction failures.

In other news, people complaining about how Presequel should just be BL2 DLC because $60 is too expensive for "an expansion" is pretty funny. If all of the content in PS was divvied up and sold as DLC in BL2, you'd be paying a lot more than $60.

In other news, people complaining about how Presequel should just be BL2 DLC because $60 is too expensive for "an expansion" is pretty funny. If all of the content in PS was divvied up and sold as DLC in BL2, you'd be paying a lot more than $60.

Got a stable 4.6GHz now, I'm happy enough with that. Still running hot though, idling at 40C, under high load hits in the 70s. Using a Corsair H80i with a couple of Scythe Sickle Flow fans (~100 cfm each) in a push/pull so don't know why it is so hot.

Thinking maybe too much thermal paste, or it didn't get spread very evenly. Gonna pop it off and redo it this afternoon when I get home from my clinical.

My GPU hovers around 40C, ~60C under load. Have five intake fans (well six technically, I have a push/pull over my HDD bay), H80i as an exhaust, and two 140mm exhausts at the top. Just can't think of anything other than a bad connection between the water block and the CPU.

what's your voltage

Jet, do you play Quake Live?

I miss Quake 3, but I can't play at the level I used to, that's for sure.

Used to add nightmare bots as fodder, now I can barely keep up at medium difficulty...

4.6GHz stable on stock voltage... talk about winning the silicon lottery. How many hours of P95 did it pass? Temps shouldn't be that bad at stock, try reseating the heatsink.

actually if you're at 1.25~1.3 it isn't stock, stock for a 3770k/4770k is 1.13v~

Huh. Bono apologized for giving out free music. What a ***.

I had to look that up... sounds interesting: this delidding.