Recent Posts

1

Beginners / Re: Understanding High Voltage and Creepage Clearances

« Last post by LoveLaika on Today at 01:47:10 am »

Thanks. Thats reassuring, but if I may...why do we assume ground has high impedance?  The creepage calculator is for voltage between traces, but do we not treat the ground plane as a trace due to its high impedance? Shouldn't we still treat it as a trace?

So, normally, I make boards with a ground plane on both sides of the board and use vias to connect them together. But, with high voltage, if we treat ground as a trace, then the high voltage nodes needs clearance away from the ground plane. If we use that conservative value of 8 mm, that's a lot of clearance, especially with other parts. It will definitely get in the way of everything else.

One option would be to limit the ground plane to just one side of the board, say the side that's opposite of your components if possible. That would leave the other side. We could always have no copper pour there, or we could not connect the copper pour to any net and leave it floating. Would a floating plane cause instability with high voltage even if it's all covered with soldermask?

2

Beginners / Re: audio amp study

« Last post by Herschel on Today at 01:43:02 am »

Sorry for my incorrect information. I glanced at the circuit and thought "Yes, that looks like a comp-sym circuit with a bias adjustment" and you folks are correct, it isn't. I looked at the website, many useful circuits and some that are really crude and half baked. The text is nearly incomprehensible.

i looked through the whole circuits in that page and this was the only circuit i found convincing. other circuits also maybe correct but they are too large for my project. i was sure that website, maybe that page was made by a person who don't know english fluently. its 100% google translated

3

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by BTO on Today at 01:30:54 am »

Zauberpilz and me had a call, as I understood it, he did not use the "01.03.03.00". Maybe that causes it?

What I also notices in the script, line 405, whatever that means?

Code: [Select]

'version': '1.0'
And I also wondered if it works for models like my MSO5104?

Interesting....

4

FPGA / Re: Lattice has silently removed free iCEcube2 license and now charging $471

« Last post by cfbsoftware on Today at 01:28:38 am »

... or at least make an free license option available for students ...

Academic License Program
We offer a 1-year Lattice Design tools license free for colleges and universities who meet our academic license program requirements. If you are a professor, and you’re interested in applying, please login to your Lattice account and fill out the application form here. If you are a student, please coordinate with your professor to join this program.

https://www.latticesemi.com/Support/Licensing

5

General Technical Chat / Re: ultra sonic transducers

« Last post by coppercone2 on Today at 01:19:53 am »

you should try civil discourse instead of trying to make nutty contraptions

6

General Technical Chat / Re: ultra sonic transducers

« Last post by pete g on Today at 01:09:26 am »

still too vague?

7

Projects, Designs, and Technical Stuff / Re: Design of white noise generator for bathroom??

« Last post by MichiganMark on Today at 01:08:15 am »

You still get a printed newspaper?!

8

Repair / Re: unknown DC-DC chip of SI-9110 differential probe

« Last post by teatime on Today at 01:08:06 am »

After remove the chip, then I draw this schematic, it's right.
The chip MAX743 is the chip I needed.

9

Repair / Re: unknown DC-DC chip of SI-9110 differential probe

« Last post by teatime on Today at 01:05:16 am »

After compare with the datesheet, MAX743 is the right chip.
Thanks alot for your great help!
 

10

Metrology / Re: reading Keysight 3458A serial number

« Last post by analogRF on Today at 12:55:03 am »

Still I would like to do the short term A3 drift test (as per service note 18A) using the CAL? 72 but I cannot keep the unit running 24/7 for 7-10 days.
I can run it for like 5-6 hours per day.

Is it ok to run it say 6 hours a day and get the temp and cal?72 after an ACAL at the end of each day and then turn it off and repeat the next day to
gather enough data?
or is it mandatory to run the unit 24/7?