Comment by rpaddock | Hacker News Reader

Comment by rpaddock | Hacker News Reader

Parent Full thread

" doesn’t damp and further load the system it’s being taken from."

Don't all of these Harvesting systems load a system? For example one of the transmitters somewhere. Yes it is microwatts and no transmitter will notice a single unit. However if we start to talk large quantity of sensors, who is really paying the price? Otherwise we are admitting that Free Energy is a real thing.

You and others may find the recently released Nexperia NBM5100 and NBM7100 of interest. While aimed at batteries it functionally translates high impedance power sources to lower impedance to charge up caps for IoT usage.

https://www.nexperia.com/products/analog-logic-ics/power-ics...

https://www.nexperia.com/products/analog-logic-ics/power-ics...

I mean yeah obviously thermodynamics aren't being violated, I think the base idea is that the background noise you're harvesting from was going to be lost as inverse square law losses anyway. Large amounts of sensors would ultimately be as a whole coupled to antennae broadcasting on those frequencies, damping them, and causing the gain circuits to automatically increase output power.

Oh for sure, it’s relative to the system being harvested from and the amount of energy being extracted though.

If it’s a train cart/carriage then not really a problem as there is so much mass and vibration to go around, if it’s the surface of a small industrial machine that needs to be reasonably balanced only producing a few hundred milli g then more of a concern.

It would need a lot of these devices for the odd mW to really make a difference. It adds up, but it's in the ballpark of a router's status LEDs. These costs are already accounted for as part of the device's operation. Critical systems might start to better direct their transmissions and to reduce side bands instead of saturating the area with energy.

Well it may push for better EMI compliance.

That’s what I was thinking.

Wouldn’t harvesting the stray noise lower the impedance of the thing being noisy, making it use more power to compensate?

Reply on news.ycombinator.com