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Samsung RF energy harvesting

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dunkemhigh:
You may be thinking of a wanker torch. Got one, don't think I've ever managed to shake it enough for it to be useful. Still, the technology does work and a few shakes could do the biz.

However, a better solution, if we're going that way, is the switch that harvests power from being pressed. Got one of those too on a doorbell - no battery, solar whatever, nothing. The act of pressing it generates enough to power an RF transmitter to get a signal to a typical wireless chime. Works very well, but the button has a little more travel than expected and feels slightly mushy. Probably not suitable for a 20-button remote.

nali:
It's far more likely to harvest RF energy from the mobile phone sat next to it on the arm of the sofa, although that's probably less marketing-friendly.

Marco:

--- Quote from: SiliconWizard on January 07, 2022, 08:05:02 pm ---- Let's assume the remote is reasonably efficient, and requires 15 mW

--- End quote ---
Ultra narrow band RF transceivers can communicate over kilometers with that power. A narrow pulse IR transmitter with far simpler electronics operating over less than 10 meter should be able to get a couple orders of magnitude below that.

tszaboo:

--- Quote from: Marco on January 08, 2022, 02:22:39 pm ---
--- Quote from: SiliconWizard on January 07, 2022, 08:05:02 pm ---- Let's assume the remote is reasonably efficient, and requires 15 mW

--- End quote ---
Ultra narrow band RF transceivers can communicate over kilometers with that power. A narrow pulse IR transmitter with far simpler electronics operating over less than 10 meter should be able to get a couple orders of magnitude below that.

--- End quote ---
This is going to use BLE for the radio, the 5mA@3.3V is in line with the cutting edge BLE microcontrollers. You need approximately the same energy for receiving. The IR LEDs are blasted with with a lot of energy in a IR remote, because they expect to be able to receive even if you point your remote backwards, and you only get reflections from the wall.

--- Quote from: SiliconWizard on January 07, 2022, 08:05:02 pm ---- Let's assume it draws about 1 µW when in standby. Optimistic here too IMO. Would require a very careful design.

--- End quote ---
These smart remotes have a lot of functionality on them. Microphone, accelerometer to start with. These will consume power even if they are sleeping. Also, I'm fairly sure the remote will have a continuous BLE connection to the TV, so a button press can happen any time, and the pairing is avoided. In my experience this paging requires anywhere 5-10 uA of current, as there is a "hello" message every 2-8 seconds.

SiliconWizard:

--- Quote from: tszaboo on January 10, 2022, 10:02:54 am ---
--- Quote from: Marco on January 08, 2022, 02:22:39 pm ---
--- Quote from: SiliconWizard on January 07, 2022, 08:05:02 pm ---- Let's assume the remote is reasonably efficient, and requires 15 mW

--- End quote ---
Ultra narrow band RF transceivers can communicate over kilometers with that power. A narrow pulse IR transmitter with far simpler electronics operating over less than 10 meter should be able to get a couple orders of magnitude below that.

--- End quote ---
This is going to use BLE for the radio, the 5mA@3.3V is in line with the cutting edge BLE microcontrollers. You need approximately the same energy for receiving. The IR LEDs are blasted with with a lot of energy in a IR remote, because they expect to be able to receive even if you point your remote backwards, and you only get reflections from the wall.

--- Quote from: SiliconWizard on January 07, 2022, 08:05:02 pm ---- Let's assume it draws about 1 µW when in standby. Optimistic here too IMO. Would require a very careful design.

--- End quote ---
These smart remotes have a lot of functionality on them. Microphone, accelerometer to start with. These will consume power even if they are sleeping. Also, I'm fairly sure the remote will have a continuous BLE connection to the TV, so a button press can happen any time, and the pairing is avoided. In my experience this paging requires anywhere 5-10 uA of current, as there is a "hello" message every 2-8 seconds.

--- End quote ---

Yes absolutely to your points. I was being overly optimistic - as I said - on purpose. Because even in that case, the RF energy harvesting would prove completely useless.

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