Some observed progress in Lithium-Ion Batteries.

I have posted before about Lithium-Ion batteries. My relatively new Samsung Galaxy S9 Smart-Phone possesses one, and seems to have better battery performance overall, than my old Galaxy S6 did. Also, both these phones had a sensor chip which measures battery voltage. I use an Android app called GSam Battery Monitor Pro, to get occasional glimpses of what my battery is doing, and without such a hardware chip, the app would not be able to provide meaningful information. On my Galaxy S9 phone, the battery has a voltage of ~4.2V once fully charged, and I’m assuming that to plug the phone in just keeps it connected to a constant voltage source…

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On my previous, Galaxy S6, when fully charged, the battery had a voltage of ‘only’ ~3.7V. And so one strategy which Samsung could be using to increase battery life, would simply be to charge the same battery technology to a higher voltage. However, usually, doing so would only result in the battery catching fire. And so, some improvement in the actual design of the battery had to take place, so that it could be kept charged to 4.2V, and not suffer any immediate damage.

Dirk

 

Dolby Atmos

My new Samsung Galaxy S9 smart-phone exceeds the audio capabilities of the older S-series phones, and the sound-chip of this one has a feature called “Dolby Atmos”. Its main premise is, that a movie may have had audio encoded according to either Dolby Atmos, or according to the older, analog ‘Pro Logic’ system, and that, using headphone spatialization, it can be played back with more or less correct positioning. Further, the playback of mere music can be made more rich.

(Updated 11/25/2018, 13h30 … )

Rather than just to write that this feature exists and works, I’m going to use whatever abilities I have to analyze the subject, and to try to form an explanation of how it works.

In This earlier posting, I effectively wrote the (false) supposition, that sound compression which works in the frequency domain, fails to preserve the phase position of the signal correctly. I explained why I thought so.

But in This earlier posting, I wrote what the industry had done in practice, which can result in the preservation of phase-positions, of frequency components.

The latter of the above two postings is the more-accurate. What follows from that is, that if the resolution of the compressed stream is high, meaning that the quantization step is small, phase position is likely to be preserved well, while if the resolution (of the sound) is poor, meaning that the quantization step is large, and the resulting integers small, poor phase information will also result, that may be so poor as only to observe the ±180⁰ difference that also follows, from recorded, non-zero coefficients being signed values.

‘Dolby Atmos’ is a multi-track movie sound system, that encodes actual speaker positions, but, not based on the outdated Pro Logic boxes, which were based on analog wires coming in. In order to understand what was done with Pro Logic, maybe the reader should also read This earlier posting of mine, which explains some of the general principles. In addition, while Pro Logic 1 and 2 had as outputs, physical speakers, Dolby Atmos on the S9 aims to use headphone spatialization, to achieve a similar effect.

I should also state from the beginning, that the implementation of Dolby Atmos in the Samsung S9 phone, allows the user to select between three modes when active:

  1. Movies,
  2. Music,
  3. Voice.

In addition to the actual surround decoding, the Samsung S9 changes the equalizer settings – yes, it also has a built-in equalizer.

(Updated 11/30/2018, 7h30 … )

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