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Test Equipment / Re: frequency displayed in Hz
« Last post by DavidAlfa on Today at 09:03:07 pm »His experiments killed the apparatus.Maybe you wanted to mean YOUR experiments and lack of reading killed the apparatus?
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Projects, Designs, and Technical Stuff / Re: PC74hct4046ap Replacement
« Last post by dj_holmes on Today at 09:01:12 pm »I hate maths 
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Projects, Designs, and Technical Stuff / Re: digital RGB LED question
« Last post by tooki on Today at 09:00:30 pm »Right, that’s how I understood it.
So why would your triangle waves be worse for EMI than the clean square waves described in the now-deleted post you replied to?
So why would your triangle waves be worse for EMI than the clean square waves described in the now-deleted post you replied to?
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Repair / Re: Rigol DP712 Output Shorted; Fuse? / I Screwed Up
« Last post by Harry_22 on Today at 09:00:11 pm »please specify the name of this part
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Other Equipment & Products / Re: Filter advice please on home made fume extractor
« Last post by tooki on Today at 08:57:19 pm »Is he using any HEPA filtration at all? Didn't see it.I second this suggestion: you want a commercial pleated filter with a quite dense, deep pleating. Rosin clogs up filters (and can be sticky, trapping other dust), so a flat filter would probably clog very quickly. Look for “deep pleat HEPA filters”.
I would be tempted to use an off the shelf hepa filter and not some sheet because they are pleated which will increase the surface area. But if you have a really large surface you can drape it across maybe it would be fine.
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General Technical Chat / Re: Cable Management
« Last post by MarkF on Today at 08:56:57 pm »My workbench is in a small bedroom and all my parts and cables are kept in the closet.
The clothes shelf in the closet is a wire mesh and I 3D printed a cable hanger to clip
onto the outer edge.
The clothes shelf in the closet is a wire mesh and I 3D printed a cable hanger to clip
onto the outer edge.
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Projects, Designs, and Technical Stuff / Re: digital RGB LED question
« Last post by glenenglish on Today at 08:56:47 pm »well, they were not really triangles, they have rounded tops.
Square waves have a rich odd harmonic spectrum, so they are more likely to produce EMI issues at higher frequencies
In addition, the high frequency harmonic content can excite parasitic reactances in the wiring (stray C, L) which generates rings and spectral components up into VHF and UHF. (maybe 1000 times to square wave fundamental frequency)..
Start with a sine wave wave, and progressively add odd harmonics and you'll end up with a square wave.
Square waves have a rich odd harmonic spectrum, so they are more likely to produce EMI issues at higher frequencies
In addition, the high frequency harmonic content can excite parasitic reactances in the wiring (stray C, L) which generates rings and spectral components up into VHF and UHF. (maybe 1000 times to square wave fundamental frequency)..
Start with a sine wave wave, and progressively add odd harmonics and you'll end up with a square wave.
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Beginners / Re: Convert US standard 115V to International 230V
« Last post by Zero999 on Today at 08:54:03 pm »My favourite one was when it took several pages to explain why a capacitor connected to a generator doesn't increase the power consumption, ignoring the tiny extra I2R losses.In order to support both 50 Hz and 60 Hz standards, the device needs to be rated to work at least within frequency range from 48.5 Hz to 61.8 Hz. This is because it needs to support allowed mains frequency variation ±3%.Once again, did you read the thread? It was figured out already that the device is using switching power supplies which support both AC voltage and frequency variants on the input.
…Radiolistener, can you delete your posts?Unfortunately, that would mean him admitting he's mistaken and going by his posting history, is something he appears to be unable to do.
I find it quite remarkable how someone whose username is “radiolistener” can be so very bad at listening!
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Projects, Designs, and Technical Stuff / Re: PC74hct4046ap Replacement
« Last post by Benta on Today at 08:53:18 pm »active loop controller- the heck is that
Well, R303, R304 and C302 comprise the "loop filter" or "loop controller" setting the dynamic behaviour of your PLL as well as suppressing ripple from your "custom IC".
Very primitive, but in many cases enough for a "charge-pump-PFD", which your "custom IC" might be.
It may be improved a bit, but a major leap would be replacing it with an active filter.
PLLs are math heavy in design.
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Programming / Re: Linux Dependency Black Hole
« Last post by mag_therm on Today at 08:49:40 pm »battleship to go after a trawlerIt is 28 of .c and .h files. I wanted to put breakpoints to trace through the math which is meandering over at least 3 of the .c
And the headers are all mixed up hard for me to follow I think due to multiple versions over 10 years.
Can all that be done in eclipse and gdb?
And Thanks for your time on this.