QI Wireless Charger Charging Pad for Samsung Galaxy S7 S6 edge Note 5 Nokia HTC 8X Google Nexus 5 6 7 Micro USB QI Phone Charger (WHL #32)

Here’s a random thing – a wireless Qi standard charger for phones!

I don’t even have a phone that is Qi compatible, but at work we’re looking into wireless power distribution AND data transfer at the same time. So I figured I can afford 1,74€ at AliExpress (mid-October) and get such an unit for myself. You know, dissect it, learn how it works, modify it to change characteristics. I previously had a look into the Royer converter or Royer oscillator for an entirely different thing – and here’s where ends meet. […]


Chart of Electromagnetic Radiations – vectorized (#P5F1)

News from the insane vectorizing bloke – the next part of the HUGE poster (see #P5 if you have no clue what I’m talking about) is sort-of ready. It’s the block on the lower left corner, describing reflection, refraction, diffraction, interference, polarization and Doppler’s principle.

Demo PNG is below (click for 8.2 MP rendering), SVG download link at the end of the page.

Lessons learned:

  • I’m at 21% of the image area now (wohoo!), but that was probably the easiest 21%. Yet, with the steep learning curve, it’ll stay at roughly 1-2 hours of clickedidoo per percent of area.
[…]

Hacker Eco-X TopFuel 5000mAh 6S 111Wh 20C LiPo battery pack (WHL #31)

Hey! What’s the thing that this blog needs the most?

Yep! Another battery post! :mrgreen:

So, last one of the big lithium batteries today. We have a Hacker (nice brand name!) “TopFuel LiPo 20C-ECO-X 5000mAh 6S” unit. I think this could be the first item to carry an EAN number (4250320228615) on the label – and it very well might be the first one where the manufacturer that directly sells these puppies (for 93€ a piece) does not appear on the first 100 Google results on exactly this number. That’s a pretty shitty rank for a manufacturer AND a web shop, I have to say…

I’m also not sure about the technical details on the shop page. […]


Kokam Lithium Polymer 5S 4000mAh 30C battery (WHL #30)

Yawn. Another battery pack. But also new hardware for the electronic load, so testing conditions have improved :)

Today’s item is a Kokam SLPB 400030-0501K(9543140H5) battery pack. Kokam is one of the big players in lithium polymer batteries, and given the battery was purchased at the same time as the last item, I guess this one wasn’t a cheapie as well. No Wan Hung Lo this time, but after all, it’s not an item that I bought… ;)

It is clearly aimed at RC stuff, having 4000mAh at 30C discharge rate, 18.5V nominal / 21.0V max voltage, 8000mA charging current. […]


modellbaufuchs 26650 6S2P 4.6Ah LiFePO4 battery pack with balancer port (WHL #29)

And another one. I’ll churn these battery reviews out once per week now, even though I said I would rather go biweekly. It’s not much extra effort – charging, discharging and then plotting the data has to be done anyway, taking some extra photos and waffling on about it on my blog is a plus.

So this week’s item is a 6S2P battery pack, LiFePO4, rated at 4.6Ah. It’s from modellbaufuchs, which I just visited in preparation for this post. Not sure if they are still in business, as their latest news item on the page dates back to early 2015. […]


Chart of Electromagnetic Radiations – vectorized (#P5)

Hey – I never met you and this is crazy…but here’s my first piece, so help me maybe? (umm, I had to look this up, for sure)

When watching good ol’ Dave’s mailbags, number 940 to be precise (starting at the 9 minute mark), I was instantly hooked when he showed the gorgeous physics poster. Being a qualified physics nerd myself and obviously having too much free time, I had the idea of…vectorizing it. For the greater good, in that case, nerdgasms in posters beyond A0 size. (is there a format beyond ANSI F for you weird yankee letter format guys?)

First things first: The poster was originally made by the W.M. […]


O’CELL 26650 LiFePO4 8S 3.3Ah battery pack with BMS (WHL #28)

Same thing again – but different manufacturer. That’s what you get when you clean up your new lab… ;)

I know, might be boring to see another battery pack with almost identical specs (3.3Ah instead of 3.2Ah), but trust me, this is like night and day – or like quality China and Wan Hung Lo.

Of course these two batteries were purchased at the same time for the same thing, and they cost around the same as well. But (spoiler!): These two units work fine.

Top view:

Nice shrink wrap, proper label (shout out to O’CELL and their caring but not nagging sales people). […]


CY UC-022-0.9M USB 3.1 Type-C Female to USB 2.0 A Male Cable (90cm) (Rant #R1)

Oooh, look at that precious hellspawn!

“USB-C to USB 2.0 Data Cable for Macbook Tablet, Mobile Phone – Black” – capturing everything that is wrong with USB-C!

Sure, carrying over the perfectly fine USB 3.0 spec into USB 3.1 and calling it “Gen 1” (in contrast to “USB 3.1 Gen 2” that is double the speed) is a huge fuckup on its own. There’s no better way to screw up a customer by allowing manufacturers to call something USB 3.1 compliant (new! shiny!) when it’s just 3.0 with a new badge. […]


26650 LiFePO4 8S battery pack with BMS (WHL #27)

This weeks article is another by-product of the ADC testing (WHL #26) from last week. Could’ve packed in there, but I wanted to share some remarks on Chinese battery technology…

So first of all, this isn’t a piece of kit that I bought myself. After testing two 12V/2.2Ah lead batteries from work that were sitting unused on a shelf for five years, I needed another victim. Those quality Panasonic cells were flat as Kansas – the LC-R122R2PG datasheets recommends 8.6V cutoff voltage at 3C = 6.6A or 9.7V at 1C. Fully charged, they delivered 1C at 7V or 1.5C at 2.5V at full charge – slow 10.5V discharging to 0.1C cutoff and recharging didn’t help much. […]


16 Bit I2C ADS1115 Module ADC 4 channel with Pro Gain Amplifier RPi (WHL #26)

Meep. We finally have a new product review, after all that editorial, recap and electronic load rubbish ;)

Today’s item in the mail is an I²C ADC on a small PCB, running four channels (or two differential ones) with 16 bit precision. Sounds nice? Well, if it holds the claimed specs, it IS a nice product! I bought it in mid-June on AliExpress for 2.06 USD. Adafruit, by the way, charges 15 bucks for the exact same thing. Do I smell profit margin?

Here’s how it looks straight out of the ESD bag:

Backside is a tad boring (keep the VDD in mind):

(there’s a floating island on the GND plane, boo!)

So, what does the friendly Asian seller claim? […]