During the rebuild of the wheelchair motors for the support trolley, I found myself needing an accurate milliohm meter to test the armature windings with. Commercial instruments like these are expensive, but some Google searching found a milliohm meter project based around the Arduino from Circuit Cellar. Here’s the original
Here’s the solar charge controller to go with the MT50 from the last post. This is the 40A version of the EpEver Tracer A series, the 4210A. This unit is large, and very heavy. Most of this weight comes from the enormous heatsink which doubles as the mounting plate for
Continue readingEpEver Tracer 4210A MPPT Solar Charge Controller Teardown
I was recently given a pretty nice LED backlit 1080p LG monitor, with the instruction that it wouldn’t power on correctly. The monitor would power on as far as the standby light, but when fully powered on, would flash the backlight momentarily then shut down. A power supply issue was
Here’s another Sony Flat CRT TV, the FD0280. This one was apparently the last to use CRT technology, later devices were LCD based. This one certainly doesn’t feel as well made as the last one, with no metal parts at all in the frame, just moulded plastic. Being a later
The Dyson DC16 is one of the older handheld vacuums, before the introduction of the “Digital Motor”. (Marketing obviously didn’t think “Switched Reluctance Motor” sounded quite as good). These vacuums have a very large DC brush motor driving the suction turbine instead, the same as would be found in a
I did a little more digging into the PSU circuitry of the small coin counting machine, and it’s even more strange than I thought! The part I originally thought was a transformer on the PSU board is in fact a DC-DC converter module! Here’s the device after desoldering it from
Continue readingDe La Rue Coin Counting Machine Followup – PSU Oddness
A lot of the electronics I use & projects I construct use batteries, mainly of the lithium variety. As charging this chemistry can be a little explosive if not done correctly, I decided a proper charger was required. This charger is capable of handling packs up to 6 cells for
On the quest to get things on board replaced that are heavy users of power, the monitor in the main cabin was next. The original CCFL-backlit monitor was very heavy on 12v power, at 5A. This meant falling asleep watching TV would result in severely flattened batteries. Replacement with a
Continue readingViewSonic VA2232W-LED Monitor 12v Conversion
All of the parts I required to complete the supply arrived this morning. After several hours of building, here’s what I came up with: I’ve mounted everything on a piece of FR4 PCB, with it’s copper plane grounded to the case. This backing board is the same size as the
Continue readingRigol DS1054Z 12v Power Supply Project – Completion
In my shack, 99% of my gear is all 12v powered, which is good for a few reasons: Single Power Supply – This increases efficiency, as I’m only getting the losses of a single supply. Safety – Mains voltages are dangerous, I’m not fond of working on such equipment. Portability
Here’s a sneak preview of my next upcoming project. The target is building a monster DC-DC converter, capable of 70A continuous output, 100A surge. Here’s the 10 modules, each rated at up to 7A continuous & 10A surge. I ordered so many that they turned up still panelised! 00
After watching a video over at Scullcom Hobby Electronics on YouTube, I figured I’d build one of these precision references to calibrate my multimeters. It’s based around a REF102P 10v precision reference & an INA105P precision unity gain differential amplifier. For full information, check out the video, I won’t go
Here is the setup used to create the previous videos, the PiCE from Elson Designs makes the Pi water resistant, the only slight modification being to install a 2.5mm DC Barrel Jack into one of the grommet holes in the rear coupled with a custom DC-DC converter to power the
The original LM2577 based regulators I designed into my mobile battery pack turned out to be insufficient for requirements, therefore they have been replaced with higher capacity regulators. The 12v regulator (left) is a muRata UQQ-12/8-Q12P-C SEPIC converter, providing a max of 8A at 12.1v DC. The 12v rail is
Just a quickie to note down the current progress of another project – Ultracapacitors. Pictured right is a bank of 6 2.5v 2600F Maxwell Boostcaps, for a total of 15v at 433.333F. A total energy storage of 48.7kJ. Coming soon will be the inclusion of charge balancing, using Zener diodes &