Recent Posts

71

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by BTO on Today at 02:15:13 am »

I confirm, rigol_kg2.py script works well.

Hey mate, can you check something for me .
in MEASURE / ANALYZE
at the bottom do you have
Eye Analysis
Jitter
?
I don't have them, just want to know if the result is the same.  I've checked and have discovered that Eye Analysis is an available
option in the MSO5000
I'm also gonna have a look over the script and see if perhaps these options were accidentally missed by DrMefisto when writing the script

72

Beginners / Re: First PCB - how does it look?

« Last post by JustMeHere on Today at 02:13:57 am »

I'd suggest a barrel jack or pin header for your VIn.  And a pinhead for your Vout.  You definitely want at least 2 GND connectors.  One for your power in and one for your power out.  Think: how do I want to connect this?

And for your fuse, consider a PTC.

Since it looks like you got everything on one side, use the botton for your ground plane.  A ground plane should only.have holes through it.  No slots.  If you add it to the top then you will have slots.  Probably not a big deal in this design, but just stay away from a slotted up ground plane.

73

Repair / Re: Desoldering advice

« Last post by antenna on Today at 02:13:21 am »

Using an X-tronic 5040-XTS-XR3.  Have not tried bigger propane soldering iron yet, just got home, will try tomorrow.  I will go out to the shop and get the board and take pics now.  I like the idea of preheating, will try that too.

74

Repair / Rigol DP712 Output Shorted; Fuse? / I Screwed Up

« Last post by zanfar on Today at 02:11:04 am »

If you want the backstory, skip to the end.

----

I have a Rigol DP712 50V/3A power supply, and I think I blew something in the output. With nothing connected, when I turn the output on, it immediately switches to CC mode (setpoint is 5V/500mA). The rear fuse appears okay, and I would expect the unit not to turn on at all if that was the problem.

The short: Is this worth diagnosing and repairing myself?

The long: How do I troubleshoot this? I have not opened the case as that will break the warranty seal. I know those are marginal at best, but I'd rather not until absolutely necessary.

----

Backstory:

I am an idiot. I saw the "#919 - How To Charge Li-Ion/LiPo Batteries With A Power Supply" EEVBlog video and had a battery pack I thought I could save. I verified the terminals and polarity, but when I attached the battery to the power supply, something popped. I detached the pack and turned off the PS immediately. It has been off and unplugged from the wall since. The pack is a 3P2S, as far as I can tell. At the time of the failure, the output was set to 12.6V/500mA, OVP at 13V, and OCP at 700mA.

I'm aware I may have just let the smoke out of $300; you're welcome to roast me, but please do so in parallel with advice. Thanks.

75

Test Equipment / Re: Decent modern Signal/waveform Generator here in early 2024

« Last post by GigaJoe on Today at 02:10:49 am »

FY3224S - I use it for a long time , as some signal source ....  it quite annoying interface where you need to press a single button to switch parameters in a sequence to reach what you need ...  in case - set and forget it acceptable , but when you quite often going to change some output parameters it kind of frustrated ..

so ...   if you need just a signal source ,   to feed something , like trace signal path  that FY32XX acceptable ....  as well you can look at old gens with limit 1-3Mhz local used \ flea market etc. depend on your max MHZ needs...  ;  or if you do TTL for 1-3MHz ...

for a work pattern where you need often change parameters,  jump to there , and there, change this and that .....   unfortunately ,   friendly generators with key pad and dedicated buttons .... only ;   otherwise after some time you will start to kick yourself   




 

76

Programming / Re: Linux Dependency Black Hole

« Last post by ataradov on Today at 01:47:23 am »

I am asking questions about the increasing problem of dependencies.

You have not actually clarified what "problem of dependencies" you have in mind. I've been using Linux since 2002, and as the only OS since 2007, and in that time I only see things improving over time (discounting whatever Canonical is doing).

So, if you can provide specific examples, there may be something to discuss. Otherwise it is just way too abstract.

77

Programming / Re: Is ChatGPT any good at writing code?

« Last post by vk6zgo on Today at 01:46:46 am »

So, no, you won't get redundant. But you're likely to get frustrated as more and more people expect these LLMs to do your job, and then come back to you to help them get out of the mess they have put themselves in. Get prepared to this to get over the frustration (the "I told you" syndrome), and you'll be fine with probably no shortage of work to do for years to come.

That's no different to what I've experienced repeatedly since the 80s: "Your $10,000 quote is too high, we found a student who said he can do it for $500".

Two years pass ...

"Hi, the student's code never worked. Can you fix it?"

ChatGPT coding might save you some typing, but it's really very much like the messages we get here and on Reddit etc all the time about student assignments "My code doesn't work, what's wrong?"  Uhhh .. everything?

It's all about perceptions.
The MBA Boss knows nothing about technology & believes all the fairytales that come out of the media, so they really believe that Chat GPT  & the like can do all these things better than a human.

78

Metrology / Re: 5.5D vintage Systron Donner 7205 DMM with 0.5% FS error

« Last post by trobbins on Today at 01:44:49 am »

I removed VR7 and confirmed no change to 0.5% FS error, so returned it.  I then checked if it was feasible to adjust the +10Vref and -10Vref levels as a way of calibrating the display value to 10V FS, and that seemed to require the internal ref levels to be lowered to circa +/-9.987 (ie. abt. -0.13% of anticipated).  The equipment instruction manual only describes calibration of the various range trims in the first analog section, effectively assuming the +/- 10Vref levels in the following analog integrator are correct.

Adjusting the internal +/-10Vref levels seems to be the simplest path forward, so I will warm everything up and calibrate the meter across the ranges to confirm everything displays as anticipated.

Ciao, Tim

79

Manufacturing & Assembly / Re: LPKF Protomat S42: Machine "shock absorber"/"stroke limiter" tuning

« Last post by rsaxvc on Today at 01:43:54 am »

> It seems that Your tool bit may be the wrong length.

That is such a a better explanation! I think I was thrown off because my machine came with a 2.95mm bit, but perhaps it is not "the" 2.95mm reference bit, which could long enough to drill into the reference strips without undoing the Z stage stroke limiter.

Say, is there any chance you would mind dimensioning an LPKF "special drill for reference drilling" bit if you've got one? I couldn't find it in LPKF's catalog.

> Adjust Your 'Z' depth accordingly in the program.
> This is the link for the software for the machine.

I believe S42 was of the last to be used with the older Boardmaster software I have, and even has manual Z stage adjustment via a large screw that adjusts the bit relative to a plastic foot, and no software Z controls other than down-time.

Thank you for your help with this.

80

Microcontrollers / Re: A couple questions about Milk-V Duo boards

« Last post by SiliconWizard on Today at 01:41:44 am »

Yep. The amount of RAM can be pretty interesting. Using a Cortex-M7, you rarely have access to anything else than PSRAM if you want more than the internal RAM, which is slow and limited to 8MB/chip (at least for the QSPI ones), or maybe SDRAM for some MCUs?

The Duo's with 256MB and over are slightly different beasts as I've seen, they include an ARM core on top of the 2 RISC-V cores. I haven't figured out yet how all 3 can work together.