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Samsung RF energy harvesting

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BrokenYugo:
It's a nifty concept but I'm also not sure it's all that environmentally friendly. I doubt I've ever burned through more than 2-3 sets of AAAs in a regular IR remote that was functioning correctly. I just changed out the original set in a 2013 Samsung remote, and that one has a backlit keypad.

It's the RF based remotes like you find on the higher end Rokus (and probably other streaming sticks) that really tear through batteries to a point a rechargeable solution of some sort probably makes ecological and economic sense.

thm_w:

--- Quote from: f4eru on January 05, 2022, 05:31:29 pm ---Who said that there are batteries inside ?
It may as well be a supercap.

--- End quote ---

They call it a rechargeable battery on their website. Either way, supercap or li-ion are fairly similarly priced. Li-ion can be recycled, supercap unsure of that, it can be re-used but thats assuming it goes into the proper e-waste channel.

So question is if 10 alkalines is equal to the environmental cost of a small li-ion pouch cell. I've probably gone through 10 AAA's on my TV remote by this point, its about 3-4 years old.

jts:
I'm not sure if I'm doing it right (probably not), but using the formula from EEVblog #55 [1], assuming the dimensions are the same as the previous model (6.46 * 2.01 inches) [2] and a 40 meter range [3] I'm getting an output of 0.04178 μW.

Could that tiny amount of power be enough to do anything useful at all?

[1]
[2] https://www.amazon.com/BN59-013-Replacement-Control-Compatible-BN59-01357F/dp/B09BKCWMSZ?th=1
[3] https://www.makeuseof.com/samsung-tv-remote-power-over-wifi/#:~:text=According%20to%20Samsung%2C%20its%20Eco,by%20pretty%20much%20every%20router.

SiliconWizard:

--- Quote from: jts on January 07, 2022, 06:19:20 pm ---I'm not sure if I'm doing it right (probably not), but using the formula from EEVblog #55 [1], assuming the dimensions are the same as the previous model (6.46 * 2.01 inches) [2] and a 40 meter range [3] I'm getting an output of 0.04178 μW.

Could that tiny amount of power be enough to do anything useful at all?

--- End quote ---

Nope. But just do the math. =)

Here is my (quick) take:

- Let's assume the remote is reasonably efficient, and requires 15 mW of power while transmitting (about 4.5 mA @ 3.3 V, to get an idea. Not that much for a remote using IR, or even Bluetooth, so it's very likely optimistic here.)
- Let's assume it draws about 1 µW when in standby. Optimistic here too IMO. Would require a very careful design.
- And let's assume the total time spent transmitting in 24 h is 30 s. Depends on your use, but at least for IR, it's probably even pretty optimistic.

Assuming I didn't mess up the calculation, that would be an average of 6.2 µW. And again, probably very optimistic already.

Assuming you can harvest an average of 0.04178 µW, that would be 0.67% of the remote's consumption. Let's assume a 90% efficiency for charging the "battery" - probably optimistic too here - we're down to 0.54 %. Even if one managed to harvest 10 times the power you estimated, that would still be only about 5% of the remote's consumption. And again that's with pretty optimistic consumption figures IMO.

But as thm_w said, it still has a solar cell, and unless you stick the remote in a drawer when you're not using it, this is where it will get most of its power from. The RF thing is marketing wank.

To get an idea of a typical remote's consumption - but maybe here Samsung managed to design an ultra efficient remote: they often use 2 to 4 AAA batteries these days. Let's take the 2-battery option, with alkaline batteries, typical capacity of 1000 mAh, so about 3 Wh. If the batteries last for 2 years, that's an average consumption of about 171 µW.

So, yeah. ;D

NiHaoMike:
Perhaps the best option would be a magnet in a tube that has a coil around it charging up a capacitor? Just shake it to charge it.

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