4 ms·

I think some people are interpreting that as a joke. I'm not talking about a net gain of energy or any crazy perpetual motion machine. Think of something like a

I think some people are interpreting that as a joke. I'm not talking about a net gain of energy or any crazy perpetual motion machine. Think of something like a "heat brake". Differential heat energy can be converted to mechanical work. Some of that can be used to cool the system elsewhere, creating a negative feedback loop. Another way to think of such a system is like the "reluctance" of an inductor. With present thermoelectric effects, using a Seebeck junction to generate current for a fan is hopelessly ineffective. But is that necessarily the case for all designs which could help to hold a system under a critical temperature when heat spikes.

acomjean 4y ago
do you mean something like a solar chimney, where heat is used to draw air through the rest of the building? https://en.wikipedia.org/wiki/Solar_chimney https://en.wikipedia.org/wiki/Solar_chimney
- nonrandomstring 4y ago
  That's an example of a similar system, but probably impractical for use in an electronics context. I have in my imagination a fantasy "smart" material that in the limit can transfer 0.5 * k^m joules of heat per square meter per second from one side to the other (where m is somewhere between 1 and 2). Such a material would always feel slightly warmer on one side and cooler on the other, and this effect would actually increase in the presence of ambient heat, hence it could act as a thermal "brake" or active heat pipe/diode. I beleieve such a device is "allowable" within the laws of physics.
dtgriscom 4y ago
The goal is to quickly and efficiently conduct heat from the DRAM (A) to the outside world (B). You could generate a little power from the temperature difference between A and B, but that would greatly reduce the effectiveness of the heat transfer. Perhaps that generated power could cool something else, but you'd waste power (and generate heat) in the process. Net loss.

acomjean 4y ago

do you mean something like a solar chimney, where heat is used to draw air through the rest of the building? https://en.wikipedia.org/wiki/Solar_chimney https://en.wikipedia.org/wiki/Solar_chimney

nonrandomstring 4y ago
That's an example of a similar system, but probably impractical for use in an electronics context. I have in my imagination a fantasy "smart" material that in the limit can transfer 0.5 * k^m joules of heat per square meter per second from one side to the other (where m is somewhere between 1 and 2). Such a material would always feel slightly warmer on one side and cooler on the other, and this effect would actually increase in the presence of ambient heat, hence it could act as a thermal "brake" or active heat pipe/diode. I beleieve such a device is "allowable" within the laws of physics.

dtgriscom 4y ago

The goal is to quickly and efficiently conduct heat from the DRAM (A) to the outside world (B). You could generate a little power from the temperature difference between A and B, but that would greatly reduce the effectiveness of the heat transfer. Perhaps that generated power could cool something else, but you'd waste power (and generate heat) in the process. Net loss.