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.
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
Anul asta nu am reușit sa ajung prea des la munte, asa ca duminica s-a ivit ocazia de a ieși la o plimbare
Vremea a fost specifica anotimpului, stabila, cald în pădure și pe unde bătea soarele, dar cu semnele iernii vizibile peste tot: gheata și zăpadă pana în pădure, în zonele ferite.
Era un strat fin de nori, dar nu suficienți cat sa oprească soarele
This is a quick post about fixing a TV that had the HDMI connector melted off the main board.
Got the TV as junk – so there was no pressure to fix it.
The TV’s id numbers are ( stickers on the main board / firmware, etc):
C/N: PC07035
P/N: CV028E_V5E0_01238
D/N: 20070322X00005
M/O:J03A117
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While working on RF stuff I got to the point where I had to tune filters and measure frequency response of amplifiers and other tuned circuits.
This implies having access to a VNA.
As something like that is out of reach, and buying an existing one is out of my budget I started out designing one from scratch.
For that I’ve used the N2PK VNA as a starting point with some small changes that I though will be useful.
The entire system will have:
Each board has a 12V input and local LDO’s for all needed voltages.
12V was chosen because the value of the MMIC’s bias network was high enough to require just a generic inductor.
I’ve used 5V for all internal supplies as all chips used that voltage.
Also, I’ve used a common PCB template – so the boards can be stacked with M3 spacers.
That will also simplify making some shielded cases, if needed – just one case template.
The overall system architecture looks like this:
Just got a new toy, to start working on some interesting projects: an HP3466A almost my age, but still kicking
Here are some pictures:
[nggallery id=7]
Hello
This is a quick teardown and fix of a Chinese variable power supply.
While trying to measure a negative power supply I’ve discovered that the negative terminal was shorted to main’s earth and case
Hello.
In this post i’ll show a quick walk-trough on how I managed to re-use an old Asus A6RP that had a sad ending.
In a few words, the entire case got smashed to plastic splinters. Luckily the internal components survived.
The case was rebuilt around two 4mm transparent acrylic sheets and 2.5mm pcb stand-offs, 10 and 15mm tall.
[singlepic id=16 w=320 h=240 float=none]
