CITYSAX 160Ah LiFeYPO4 battery discharge and teardown (WHL #51)

Speaking of electric cars: A colleague recently bought a used electric car and (obviously!) contacted me in order to diagnose/troubleshoot it. Sadly he was able to sell it for a profit before we got it fully fixed, so no live data recordings, no power/torque graphs, no nothing to show here. But he left me a dead cell for which he got a replacement from the seller right away, as the traction battery had voltage dips under load that indicated (at least) one damaged cell.

If servicing individual battery cells sounds a bit strange for a modern electric car, that’s because we’re talking about a CITYSAX from a company that is conveniently named the same. […]


Driving a Tesla Model S and visiting tech museums in Sinsheim and Speyer (#E11)

This week I was on vacation, actually one of the first days of annual leave in 2019. Technically it was only four out of the five days and I visited the company once (for personal gain of myself and others), but I finally got away for significant amount of time. And to make it a fun experience, in additional to figuring out which car to buy, I rented a Tesla Model S 85, 12/2014, equipped with AP1 and Tech Package only. Booked via Turo for an amazing 58€ per day (three days minimum).

Enjoy an incoherent assortment of photos from those three days, in which I visited Technikmuseum Sinsheim and Technikmuseum Speyer (same association, pretty close to each other – 6h+ required each), did some 200km/h on the Autobahn to and from those locations, and generally had a good time. […]


HP 6644A refurbishment – front panel, back protector (#P14F)

Time to finish the HP 6644A revamp!

tl;dr for the last post: Here’s where I stopped refurbishment after cleaning and replacing caps and fan:

First off, those leads stick out quite a bit at the back as well. I can’t really say which diameter I used, judging from the yellow cable lugs these were 4mm² for the power lines and 1.5mm² (red lugs) for the sense lines. Apart from not fitting the old protector, that one already has seen some damage. Probably because it is so tiny…

So: Redesign. Twice, as the first version that closely resembled the original design had really flimsy legs that suffered the very same fate. […]


AliExpress order list aggregator script and more (#R8)

Things you might already know: AliExpress is a shitty website.

Don’t get me wrong, I shop a lot at AE. But the page is extremely slow due to massive amounts of JavaScript bloat, and aside from JS, it’s hacked together like I would do for a quick proof of concept. That shit would never fly with me, but for AE, it just does the job. When adding bling and JS spinners has priority over code quality…

It also annoys the fuck out of me for resetting to German translation pretty frequently. I. DO. NOT. WANT. YOUR. FUCKING. TRANSLATION. DC-DC buck modules are not money modules. […]


Hiland M644 Multifunctional Transistor Tester LCR Resistance Inductance Diode Capacitance ESR Frequency Meter PWM Signal Generator (WHL #50)

Another component for one of the upcoming projects – a refreshed transistor tester.

I’ve been using these for ages now, I actually built two of them before they got popular (what a hipster thing to say?) and every Chinese seller decided to roll his own. The original thread on mikrocontroller.net dates back to early 2012 and the SVN repository even contains a few fixes of mine to the manual, as I was proofreading this thing at the time.

Times have changed, and the ready made versions are so cheap nowadays that homebrew really doesn’t make any sense any more. […]


Failed Philips 46PFL8008S/12 display repair (#P15)

And now for the thing that didn’t make it #100 ;)

A while back, I was donated my second “defective” TV, a 46″ Philips 46PFL8008S/12 with the large ambilight (left/2x top/right with 9 LEDs each). Unlike my first donor which pretty much suffered a direct lightning strike (as described in rant #R2), this one turned on just fine. What’s wrong with it, why would you give away a former 1500€+ device?

(bonus brownie points if you can name the show currently displayed here!)

Well, story is this poor fella cracked a glass table. […]


Useful Arduino libraries (#E10)

Here’s a random thing: I’m currently tidying up work projects and I decided to stick all Arduino (and later: Kicad) libraries into one company git repository to not only back up local progress, but also to make it easier to sync a few lesser used machines with my main one. And as I often ping back and forth with my home gear (yes, idiots like me like to tinker at home as well), I always run into troubles manually syncing those.

git submodule add does a great job here – no need to upload all stuff to the main git, it’ll record independent submodules and clone them as required. […]


Post #100 HP 6644A refurbishment (#P14)

Not that anybody cares, but this is actually post number 100 already. I prepared something else that failed (to be reported!), so this one has to do instead ;)

My “lab” power supply situation is ageing and often no longer up to the task, think of LEDs north of 35V or anything that takes more than one amp at voltages that cannot be provided with common computer supplies (3.3V, 5V, 12V, 19/20V) easily. So this is part one of the refresh.

I bought a HP 6644A power supply around six weeks ago off eBay, at 245€ including shipping and rack mounts via best offer. […]


DIY USB and SATA panel mount connectors (#P13)

Next batch of connectors incoming! (yes, I’m onto something)

I bet most of you are familiar with USB panel mount connectors, which (I guess) are a by-product of the slot mounted USB ports of PC mainboards in the late 1990s, early 2000s. Back then, boards had none or few USB ports on their back I/O panel, but often one or two available via pin header. So people obviously needed some slot adapter for them, something like this:

If you slap on a different connector on the other end and omit the metal bracket, this is basically what you get these days when buying USB panel mount connectors. […]


DIY Phoenix VS-PSC style connector (#P12)

Okay okay, “project” is a big word for this. It’s a teeny tiny DIY thing, sparked from MOQ/packaging size worries of a rather unique connector.

In preparation of other things, I wanted access to the data lines of an USB port that is panel mounted. Just tinkerer stuff, you know, seeing if there’s any communication effort happening at all, being able to set current (allowance) sense resistors, you name it. I could have looped all wires to a second/third USB port and made an adapter for it, but that would be a lame one. Instead, I googled for IDC connectors, ideally female to allow easy resistor insertion, which can be panel mounted. […]