24V to 12V 5A 10A 120W DC DC Converter Step Down Daygreen 1A 2A 3A 6A 8A Voltage Regulator Newest Type CE, 10,000pcs in Stock (WHL #44)

[Just updated to WordPress 5.0 – slight errors in the Matrix might occur]

Overengineered parts from China aren’t really my cup of tea, but this is for an upcoming project with power-hungry, rotating AND rusty plates, so I figured I would use something up for the task…

…and I don’t think I paid that much of a premium for it. So today’s item is a step-down converter model “D121” rated 10 amps at 12V, with 15-32V input voltage. Price was 2.86€ at the time; contrary to the usual item on this site, this was without shipping cost. […]


PWM Pulse Frequency Duty Cycle Adjustable Square Wave Signal Generator Module (WHL #43)

Haven’t reviewed a lot of China gadgets lately, have I? Well, what about a tiny PWM generator…

I remember having the need for some good old TTL PWM signal and being too lazy to program an Arduino for it. I mean it is dead simple and there are examples included, but hooking up some knobs for live modification of the duty cycle and possibly the frequency as well, nah. There has to be a Wan Hung Lo solution to this, and indeed, there is.

This unit was actually purchased via eBay, as Ali wanted significantly more money for it. I’ve checked and now the eBay is the more expensive dealer, as it basically always is these days. […]


Fujitsu P20-2 CCFL to LED conversion (#P9)

Okay, so here’s something that I wanted to do for a long time, but it makes no sense in terms of time and money. But hey, I finally did it and it was fun!

I’ve shown my old Fujitsu P20-2 monitor previously as a comparison to the current 3440×1440 setup. It’s an old prosumer-grade 1600×1200 display, 20″, 60 Hz S-PVA panel with VGA and DVI inputs. Really good stuff. I got two of them after they failed by the dozen at university, where the tech guys even did a capacitor swap (these were in the upper three-digit Euro range when new, their replacements are totally overpriced 2560×1440 displays for 700€ a pop). […]


BenQ EX3501R frame skipping with AMD and Nvidia GPUs (WHL #33F6)

Another quick follow-up on the BenQ EX3501R (yawn).
“sss” noted that there’s an issue with their Nvidia GPU and regular 100 Hz operation, FreeSync most likely isn’t the issue here (greedy bastards). (S)He’s having missing frames leading to e.g. jerky mouse movements, which can also be detected by running the UFO test and taking a picture.

Well, so I did.
Radeon 380, 100 Hz, FreeSync enabled but not active in plain Windows mode. Test needed Chrome browser for a) performance (FF you laggy bitch) and b) V-Sync reasons, as FF cannot get its shit together, especially in full screen mode. […]


ESP8266-DHT22-SR501 kitchen lights thingamabob PCB (#P7F1)

Alright, software aside, back to hardware…

The ESP module shown in #P7 slowly gathers dust in my kitchen, which is tolerable for a few weeks, but that’s not the solution I want long-term. Also, it’s on a separate power brick, meaning there are two microcontrollers running in my kitchen for doing fancy light switches and some air quality logging for twice the standby current. Nope, has to go, needs to be consolidated into one unit.

So a while back I designed this PCB and ordered it (once again) at OSH Park, together with some teeny-tiny DIP adapters that cost next to nothing. […]


Theme Font & Size Changer for Thunderbird 64.6 fixes (#E6F4)

Yeah, f*ck me, why am I doing this.

Okay, so after a few requests and complaints about issues with TB 60.2.1 and 63b1, I spent the last hours digging deeper. That’s a mess, and not only on the code side of this addon, but also in terms of Mozilla. Well, who would have thought.

64.6 was just uploaded to the TB repository, could take a week to get that approved. Took care of zoom field and fonts list, also updated some more stuff that got disabled already or will get disabled in the near future.

Zoom. Not as in the Mazda cars, but as in layout.css.devPixelsPerPx. That actually was set to an oncommand on the text box itself, which, after I finally got it to break in 60.2.1, never again worked in previous versions. […]


Static over DisplayPort (WHL #33F5)

Okay, I admit – this is a lazy one. But I’m busy playing Path of Exile :mrgreen:

Before removing the faulty Ednet DisplayPort cable from my desk, I gave it another shot and tried capturing the artefacts on camera. A tad difficult as I noticed that the most prominent stuff is only visible on a pure black (#000) background and is very much gone on colorful backgrounds or even patterned images. Which makes it quite hard to capture without the noise from the now pretty underexposed camera sensor. And the autofocus has nothing to focus on, because if there is, the fault goes away. […]


BenQ EX3501R, AOC U3477PQU and a faulty DisplayPort cable (WHL #33F4)

Well, who would have thought that the BenQ needed another blog post…

Last week, the line flicker described in got significantly worse. I switched graphics cards the week before (Radeon 260X out, 380 in), which resulted in a driver reset and one Windows boot for the short sighted, but it also caused a bit of movement on the cables, as my computer is rack-mounted. Flicker stuff was the same for a few days.

Then it got so bad that it not only had those intermittent lines, but there were entire blocks of lines just black, audio stuttered, and the entire screen went dark for a second every so often. […]


Bloody chip markings (#R6)

Geez. Just wasted half an hour finding a part number with the actual part in my hands. Maybe I’m getting old. Maybe I should have slept more or less (noon isn’t too bad on a Sunday, is it?). Maybe chip markings are getting dumber with every nonsense package invented. Maybe I should purchase components on my own so that there’s some mail history about it. Who knows.

Care to find that on your own? Now’s the time.

Hints: That’s not TO-220, obviously. It’s also not D2PAK/TO-262 (available in DPAK, though)

It’s a N-channel MOSFET with LV-TTL compatible gate threshold voltage. […]


FlowerPower LED GrowLight POWERLIGHT 400W Repair (#P8)

Yeah, sorry for not delaying this until I could declare project #P420, but sometimes I’m a little impatient to get content online. After all, I’m not as enthusiastic about this silly number as some folks apparently are. Which also means I’m getting paid in hard cash and not in kind…

So for today’s repair project I have a quad-100W growlight unit on my desk that was in mortal agony when it arrived. The thing does not have a power-on indicator (usually you do know when it’s on…), all it did was some dim, erratic flickering of the LEDs. […]