Recent Posts

1

Other Equipment & Products / Re: What's the highest magnification you use on a microscope and why?

« Last post by jfiresto on Today at 06:44:04 am »

I use an Amscope similar to @Svgeesus, but I went with the 3.5x-90x, which is the same scope plus an additional 2x Barlow lens that I use mostly for non-soldering purposes.  For soldering, I typically have the 0.5x Barlow lens installed, so I'm working in the 3.5x to 22.5x range.  At 22.5x, a 5mm spot fills your field of vision, so you would only use that for the finest pitch components.  At 90x, you can fit about 2 pins of a 0.5mm-pitch chip in your field of vision, so it's maybe helpful for inspection in relatively rare cases.

I'm no microscope connoisseur, but the Amscope feels like it has decent optics.... Maybe this is out of ignorance, but there's no way I'd spend 2x or more on something higher-end since I have no complaints about this one.

It all depends what you will do with the microscope. You can use a routine Greenough microscope, like a range that Amscope sells, for a lot of good things, but for some applications, a higher end model can be anywhere from a blessing to a necessity. A Common Main Objective microscope with a plan objective, for example, is well nigh a requirement for taking accurate measurements, especially at higher magnifications away from the center, where a Greenough model progressively loses focus. (You can address that by tilting the specimen – what my father did with his SMZ-2T – but that can get old if you have to do it much.)

The important thing is a microscope that makes you happy. A good microscope is a godsend as your eyes get older, and will serve you well for years if not decades.

2

Test Equipment / Re: ANENG goes crazy with new meters

« Last post by Phil1977 on Today at 06:42:18 am »

And people rode cars without seat belts, motorcycles without helmets, etc....
Rules and regulations are written in blood and usually have a reason. Meters being sold with lies on them about their safety is a big problem IMHO. People being aware of what is safe, or not, is a good thing. Ignoring rules just because ancient apes didn't have rules is not a good thing.

Definitely no discussion necessary - safety evolution is a great thing and without any of it at least half of this forum would probably be dead.

A problem about having a poorly built meter lying around is that people get lazy and might think "well just this time I will be OK"

Sorry for being polemic here, but MAYBE the future of civilization would be even more granted if people do not absolutely arbitrarily plug in everything everywhere - at least on job sites. THINK before putting something on mains, and if you can't do that, then stay away 1m or more!

Of course, in companies with shared accident responsibility it´s different. There I also always recommend good equipment becuase luckily companies I work at can afford it. But if someone can't really afford it, I´d never complain about a "bad" DMM just laying around.

Or another provocative example: Bad luck can make your "wall wart" SMPS explode like a cheap DMM. Do you also equip *each* low power application with at least a CAT II fuse or charge your smartphone with a flashover suite?

 This thread is a sticky for a reason. It may be out of date for current models but the reasons and information still are valid.
https://www.eevblog.com/forum/testgear/a-list-of-multimeters-that-do-not-appear-to-meet-their-claimed-safety-specs/

This list is great, but because manufacturers are more or less lying about their products. Sometimes they lie so much that it is more than obvious - like a small €6-meter I have on my bench that is labeled as CAT IV 600V. I´m quite sure it´d be quite an incandescent device at the specified high voltage spike.
But others seems more beefy outside and aren't inside. These can really be dangerous e.g. at construction sites and there the list really may save lifes.

3

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by Performa01 on Today at 06:40:04 am »

Wanted:
Displaying the waveform update rate (as seen on the new Magnova scope).
Has already been heard and judged to be a good feature, but has not yet been added to the list.

Added to Wanted Feature No.35. This way, there is no need to connect to Trigout to test the waveform capture rate.

This would be a nice (yet not very important) feature; only question remains: where to put that information?

We already have no space for the really useful information, like the Acquisition mode, which has to be written right into the trace area of the screen.

This is acceptable only because this information is essential - especially in higher class instruments for Average Acquisition, where we want to see the number of averages completed so far, or ERES which helps us estimate the actual bandwidth but also Peak Detect, which destroys the original waveform and helps explain unexpected results in cases where it's used thoughtlessly.

There is absolutely no unused space left, especially on the SDS800X HD, where there is less space available on the screen becaue of the bigger fonts and we already had to sacrifice the Math menu item for that.

Maybe we should request an (optional) Info box in the bottom area, similar to the Timebase info box, where we can have the Acquisition mode together with waveform update rate. In general, info displays in the trace area should be optional and movable at the very least - smilar to the FFT info block.

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Power/Renewable Energy/EV's / Re: How to test an IR2104/2111?

« Last post by Andy Chee on Today at 06:35:52 am »

What are you observing on the HO and LO pins?

No signal,  just DC.
For IR2111 I've got:
 LO 11V.
 HO 2V

I'm still confused.  Your first post you attached a scope photo.  I thought that photo was from your real scope?  If so, your chip appears to be working perfectly.

5

General Technical Chat / Re: Cheapest way to get date/time from GPS

« Last post by dietert1 on Today at 06:24:54 am »

In Germany we also have DCF77. The advantage with GPS is availability of cheap and easy to use receivers. To make a good DCF77 receiver with similar accuracy one probably needs a rubidium local oscillator, so it can't be competitive.

I don't have that USB confusion in my results on the STM32L476 LSE crystal oscillator. It's a free running crystal oscillator and it serves as a clock. Typical accuracy i see using the "smooth calibration" RTC feature is 0.1 sec per day and this may still improve after implementing aging and ambient temperature correction.
Depending on required accuracy one could turn on GPS maybe once per week or once per month.

Regards, Dieter

6

Test Equipment / Re: SDS800X HD Bug Reports + Firmware

« Last post by ebastler on Today at 06:23:59 am »

Just replying to "subscribe" to this thread.

Could you update your signature to point here and to the newly renamed "Features" thread? That might help others to get their bearings. It currently still points to your original bug/features summary post, in the thread which is now focused on feature suggestions.

7

Other Equipment & Products / Re: barely used Quickoo T12-945 died during heavy soldering

« Last post by Phil1977 on Today at 06:19:58 am »

Most of these low-price solder stations do not really have a good solder quality inside themselves and inside their plugs.

After exchanging the tip with the heater inside, I´d check out all stranded wire connectors, e.g. the metall plug of the iron itself. Just check with a multimeter (no CAT rating needed  ) the heater resistance. It should be somewhere between 6-10 Ohm, if it´s much higher it´s broken.

If you open up the handle of the iron you often find an illegal mercury tilt switch. Just FYI.

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

« Last post by MichiganMark on Today at 06:13:34 am »

You clearly have significant expertise in acoustics, and I very much appreciate your help.  I just put up a general response to everyone, and am hoping you can provide me with more technical information about using white versus pink versus brown noise to mask bathroom sounds.  As I see hear it, there are two nuisance sounds to mask:  urine hitting water or the toilet bowl, and flatulence.  Do you have any information about the frequencies of these two sounds, and thoughts about whether pink noise would mask both.

I enjoy getting both the fun and serious responses I'm getting to my post, but this really is a problem I need to solve.  I'm currently using a small portable white noise generator in my bathroom. Kt's ok, but requires me to turn it on manually each time I use the bathroom.

My wife wants to also have noise generators in two other bathrooms that guests use to ensure they aren't embarrassed if they generate nuisance bathroom sounds.  We don't want to give our guests instruction on how to use little bathroom noise generators, thus a noise generator that comes on automatically would be the best solution.  I'm very good with electrical circuitry, and want to put a noise generator in the ceiling controlled by a motion detector set to run for 10 to 15 minutes.
,
Also, based on what you know, how much better sound absorption is there with a solid-core door versus a hollow door?

I've found several schematics on the Internet for building low-voltage white noise generators, but they don't provide me with much information about the frequency or decibels of the sound they create.  There are also hobby kits available on the Internet for low cost, but again they don't identify the sound generated.

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Other Equipment & Products / Re: What's the highest magnification you use on a microscope and why?

« Last post by Phil1977 on Today at 06:12:06 am »

  Maybe this is out of ignorance, but there's no way I'd spend 2x or more on something higher-end since I have no complaints about this one.

No, that does not sound like ignorance at all, for me it sounds like perfect reasonability...

Thanks for the feedback, if I ever soo an Amscope on a workplace or tradefair I´ll check it out. If eyes get worse with age I may even get a personal one as a kind of anti-aging-measure for the eyes 🙃

10

Thermal Imaging / Re: what surface do you use for evaluating lights?

« Last post by _Wim_ on Today at 06:07:27 am »

...look at integrating spheres - not cheap, but basically a matte reflective material all over a spherical interior surface with some mechanism to hold/power a device in the middle.

Quite possible to DIY also for not that high of a cost, see

Styrofoam hollow spheres that can be bought at a crafts store also work as quite an acceptable sphere. What kind of spectrometer you want to use it with?