Some time ago I got an old QNAP NAS that uses two ACE-R150 power supplies in a redundant connection.
They where noisy from the start and they got worse as they drew in extra dust from the CNC machine, to the point where I could no longer work with the NAS powered on.
This is a quick build around an AL8843 step-down led driver from Diodes inc
It uses the reverse buck topology, where the switching mosfet is referenced to ground, and the output is referenced to Vcc. This works well for loads that don’t need a ground connection – LED’s for example.
It also simplifies the chip internals because there’s no need for a floating gate driver and a charge pump to power it.
Lately I’ve been building some custom battery packs and I’ve been unlucky with the cheap BMS boards.
That’s why I’ve decided to build my own – something that could work stand alone and provide basic protection.
For that I chose the BQ77904 and BQ77905 from TI.
They have all the functionality that I need and they can be chained to create up to 20S packs.
Hello,
This post is about a new project that i’m using as a start-point for a bigger one.
The final target will be a BMS system for a 10S or 15S battery, like the one that’s used in electric bikes / push-bikes
After checking the datasheets and the available parts, I’ve decided to use the following system setup:
I’ve decided to start with a 5S chip for 2 reasons: I had a 4S pack available to play with (a pack used for a modified car vacuum cleaner) and because I wanted to limit the amount of available energy and potential damage if something went wrong.
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I was bored while waiting for some other things to finish and I remembered I had some high voltage transformers pulled from some scrapped laser printers.
They have two coils, one at around 100uH, the other at over 40H. I’ve always wanted to try the MOSFET based push-pull resonant converters and they where the ideal candidates
Some time ago i got an ADSM302 digital microscope to replace the aging metallurgical microscope I’ve been using for the last 10 years.
Here are some links about it, and some short clips of my own:
This post discusses about the basic software architecture as it at the publish date. I’ll update it as things change over time.
I’ve decided to use the Arduino environment for it’s existing libraries.
Some time ago I got my hands on some IV22 VFD tubes.
They’re quite large 7 segment displays with the specific greenish-blue color
Several days ago a friend gave me 3 defective displays that were in the dumpster at his office. They where complaining that the image was unstable, they where shutting off, etc.
That made me curios if the CCFL’s where dying or they had some power supply problems, as all 3 are very old monitors with a lot of run hours
Disassembling them revealed that at least the power supply had better days. Most of the low voltage capacitors where faulty.
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After disassembling my Inokim Light for a spring-clean-up I’ve found out that it has severe water damage inside, after running on wet roads all autumn, and getting submerged once in a deep puddle.
It looks like, because of the shape of the frame, front lid placement and the synthetic sponge used to secure the battery, water pooled on the bottom of the unit and remained there for a long time.
Also, no care was given for connector protection.
