Teardown: Pixel Stand offers faster-than-Qi wireless charging for (some) Google fans

文章：Brian Dipert

在我的里面2019年3月下旬的无线充电状态更新文章，这是在单线圈Q1充电器拆卸and ahead of thesubsequent dissection of a dual-coil unit， 我写：

Google添加了本地人（与笨拙accessory-supplemented）无线充电于2018年底向Pixel 3智能手机家族充电。最后一个是“ Gotcha”预选赛的来源…unlicensed third-party chargers are restricted to 5W capabilities. Even now,六个月后, your only option for 10W charging on Pixel 3s is Google’s own $79 Pixel Stand (due to concerns about compatibility? Profitability? Both? You decide.).

从那以后，我一直在渴望进入一个人，并试图弄清楚它如何进行差异化技巧。回想起来，我唯一的陈述不是exactly准确，尽管实际上我仍然是现场。作为9 to 5 Google写上去I’d linked to earlier noted, Belkin had also announced bothpadand站立“ Boost Up”充电器的变体，它为像素手机提供了10W充电功能（以及对标准电话的5W支持）：

它们不再可用（我在这里链接到亚马逊产品页面，因为贝尔金（Belkin）网站上的相应页面不再存在），我的感觉是他们从未发货。具有讽刺意味的是product page for the first-generation Pixel StandalsoGoogle网站不再存在；它可以自动到该页面的新发布（但在我写这篇文章时尚未运送）第二代像素架，为最高23W的充电功能提供给latest Pixel 6 series phones,阿龙g with up-to-15W support for other EPP-capable phones:

Here’s the亚马逊页面第一代像素站as an alternative info source.

Speaking of compatibility, what’s with the “(some)” qualifier in this write-up’s title? The first-generation Pixel Stand was introduced alongside the像素3and larger像素3 XL，第一个包括无线充电支持的Google手机（链接与这两款手机的Ifixit拆卸有关，因此您可以看到充电器的电路有效地搭配）。也就是说，它还以高于5W的充电速度支持继任像素4和像素5。确实如此not, however, support the “A” Pixel variants, which tend to be the primary phones I use, and which (among other things) omit wireless charging support as a cost-savings move.

Enough overview; let’s get to tearing down! I’ll as-usual begin with some overview shots (I bought this particular unit off eBay; the stand itself is unused but the original owner retained the 1.5m USB-C cable and 18W USB PD power adapter for wired-charging use with a phone):

Behold our patient:

请注意（在使用之前）在电荷板上（删除）保护性塑料膜。下面是架子的独立镜头（除去塑料膜），同时是0.75英寸（19.1毫米）直径的美国便士，用于尺寸比较（根据亚马逊产品页面，像素架，尺寸为4.1 x x3.6 x 4.1英寸，重5.6盎司）：

And now with one of my Pixel 3a phones (which again don’t support wireless charging…think概念here, folks) mounted on it:

卸下手机，翻转像素倒置，然后……更具保护性塑料！

Removing it gives a clear view of the USB-C port:

顺便说一句，还在底部盖章（除其他外）是FCC ID：2APYSG019C. For what it’s worth, the certification documentation identifies the unit as a “Lanto Electronic Ltd Wireless Charger.”

Time to dive inside, beginning with the bottom, which ended up being easier to remove than I’d feared. Unlike这个尼安德特人, I chose a civilized small flat-head screwdriver, not a hunting knife:

拆除几个标签，拉开一些胶水，然后：

Not much to see yet, though those two Faraday cages (or heat sinks? Or both?) are intriguing:

在这一点上，我将注意力转移到了充电垫上，它再次很容易地分开……至少到了：

It stubbornly refused to completely detach from the base; that is until I revisited the base, removed two screws from the center and snipped some wires:

That’s better!

前盖的内部（底部）没什么可写的，但是后半部分（顶部）更有趣。从概念上讲，它让人想起塞内奥单元的两层布局EDN2019年12月出版，配有“肖像”（顶部）和“景观”（底部）线圈取向（将两种可能的设备取向优化时，都放置在支架上；顺便说一句，您是否还注意到充电器内置的漂亮脊，以保持从滑倒的设备？）。但是它在每个线圈的中间添加了一个方形的传感器（或某些东西）：

我猜它们是用于温度监测的目的，以防止过热。读者？

The back of the metal (versus flimsy plastic with the Seneo) plate that holds the two-coil assembly together is stubbornly sticky-taped to the plastic half-chassis behind it:

And with that, let’s return our attention to the PCB in the base. Initial disassembly steps were straightforward, once I removed four more screws and peeled the metal plate away from the plastic top chassis piece:

在这一点上，我最初很难过。两个金属“裂片”（由于缺乏更好的单词）被牢固地固定在PCB上，并抵制了用平坦的头螺丝刀将它们撬开的所有初始尝试。因此，我暂时将注意力转向了PCB和其后面的金属板之间的连接，这对我的哄骗更适合：

Here’s a close-up of the translucent lens that focuses and redirects to the outside world the output of the PCB-located LED:

说到……回到PCB前侧。您是否已经注意到这七个洞：一个“叶”中的四个，“另一个”中三个？

Well, I tried jamming one tip of a precision tweezer set in one of them and using it to lift the “lobe” off, which only resulted in me bending the tweezer tip. A heat gun didn’t do the trick, either, although via its application I learned that the PCB backside included several pieces of adhesive protective tape:

However, I’m happy to report that one final application of the flat head screwdriver, with a bit more muscle (and colorful accompanying language) and also leveraging the USB-C connector as a fulcrum, was ultimately successful:

瞧。首先注意上述LED在PCB底部。

Let’s peer closer:

In the bottom left quadrant of the photo are two landscape-dominant ICs: anIDT (now Renesas) P9242-Rwireless power transmitter “for 15W applications” (I’m quoting the datasheet) and aWinbond 25X40CLNIG4 MBIT串行闪存。右上象限中有两个标记的设备：

6996
Ga8x2d

This teardowninformed me that they areAOS AON6996dual N-channel MOSFET devices. There are two more of them on the other side of the PCB:

Along with them is a mysterious (at least to me) STMicroelectronics STM32 microcontroller (you may recall that I was unable to definitively identify the STMicro µC in the Seneo teardown, either). Again…readers?

I admittedly exit this project still a bit frustrated, because I wasn’t able to sort out exactly how the Pixel Stand knows that it’s got a Pixel phone sitting on it (versus a conventional Qi-supportive device) and accordingly boosts its charging power. Withinthis Reddit mini-teardown and discussion thread是一篇帖子，该帖子假定“绘制10W的能力是由嵌入QI传输中的数据流触发的。”

I’m not aware of any specific over-the-air handshake like this that occurs between the wireless transmitter and receiver, but then again I’m admittedly not intimately familiar with the Qi specifications, either. All I’ve been able to ascertain from theQi entry in Wikipedia这是：

Regulation of the output voltage is provided by a digital control loop where the power receiver communicates with the power transmitter and requests more or less power. Communication is unidirectional from the power receiver to the power transmitter via backscatter modulation. In backscatter modulation, the power-receiver coil is loaded, changing the current draw at the power transmitter. These current changes are monitored and demodulated into the information required for the two devices to work together.

在知识渊博的读者对此或我介绍的任何其他内容（或Overlook）的评论中的反馈都受到了欢迎！

This article was originally published onEDN.

Brian Dipert是Edge AI和Vision Alliance的总编辑，也是BDTI的高级分析师，并且是公司的在线新闻通讯Insiderssp的总编辑.