Recent Posts

1

Beginners / Re: good/cheap headphone aplifier/dac?

« Last post by BeBuLamar on Today at 10:08:19 am »

If you like the Bose QC25 why not just buy another?

2

Repair / Re: Artesyn LPT42 SMPS repair

« Last post by zkrx on Today at 10:06:33 am »

Thank you so much. I still have a few incandescent bulbs lying around.

Any tip for testing IC1 (3842) or should I just blindly swap & test?

3

Projects, Designs, and Technical Stuff / Re: Automotive hardening?

« Last post by coromonadalix on Today at 10:05:08 am »

dont forget humidity and vibrations

4

Beginners / Re: Any help? Raspberry Pi prod counter w/ reflective sensors - output concerns

« Last post by BeBuLamar on Today at 10:05:06 am »

With a PLC it's simple to have the PLC record 2 count values and store it in the PLC however to read these values you need to use the software that you use to program the PLC to read them or you have to use an HMI software or a hardware HMI which is more costly and and involved. However, I think you have all the parts and tools needed to use the PLC for counting I think it's a good idea to just do that first and see if the count values help you then develop something else.

5

Test Equipment / Re: Looking for a replacement general purpose oscilloscope for home use

« Last post by moerm on Today at 09:57:24 am »

But: I would not (yet) consider their 6000 and 7000 series as a serious option.

Friendly regards

Could you elaborate why, if you are willing to?
What is making you say so?

Thanks and best regards,

Siniša

Diverse reasons, the main one being that maturity isn't achieved "overnight". With Siglent scopes, I'm talking about the up to 3000 and 5000 series, maturing could be observed and maturity has been reached. That also means and includes practical experience and many details e.g. in, but not limited to production and firmware. But reaching maturity needs time and the experience coming with it.
Also the 80/20 rule plays a major role and that also again translates to time. To put it simply, pretty much any company, and many chinese companies demonstrate that, can design and produce an "80%" scope but it's the remaining 20% that really need time, experience, and major efforts (and money) and one should note that quite a few companies (Owon comes to mind as one example) seem to not even care and to intentionally address and (largely) build for the "80%" market that is, basically kind of nice instruments but with kinks, weaknesses, no or few and late firmware updates, etc.

It's the remaining 20% that make all the difference. With scopes up to 3000/5000 series Siglent IMO has had the time, has gained the experience, and has demonstrated the will to go "the extra mile", in short, became a mature player.
Scopes in the GHz range though is a different breed of beast (also in terms of $$) and while I have no doubt that Siglent will achieve maturity there too I think that one should not underestimate how much time is needed for that.

Also, of course, for a hobby lab the $1000 to $3000 region probably is within range, at least for many, the $10000+ highly likely is not. Plus, reviews and teardowns play a major role in that market and as of now (credible) reviews and good and full teardowns of the high-end series still are rare. To put it bluntly, before I (or most hobbyists) shell out $10000+ (plus active probes which as of now are as few as teardowns and not exactly cheap either) I, at a very minimum want to see some credible reviews from collegues I can take seriously (i.e. e.g. max 1 'lol' per post) and some teardowns.

As I said, I don't have any doubt that Siglent sooner or later will arrive there, but as of now IMO they are not yet really there.
As a side note, that also shows in their active probes. AFAIK a 1 GHz and a 2.5 GHz active probe is all they offer so far (and with very little info/details).

Friendly regards

P.S. What I just wrote also shows in humans and human thinking (or "thinking"). Just one example: IMO for a mature person thinking not just superficially, active probes and >= 1 GHz scopes go hand in hand. After all, what good is a 3 GHz scope without, preferably good and mature probes? LeCroy, for instance, has quite a few mature, "battle proven" active probes and plenty of info on them.

6

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by AndyC_772 on Today at 09:50:35 am »

Just unboxed my new scope and getting to grips with it - apologies if this is just a setting which can be changed somewhere, but it seems unintuitive and a limitation...

I'm probing a CAN signal - actually one of the training outputs from my MSOX3104A - and before I can decode it, I need to know the bit rate.

I couldn't find an automated measurement that gives this quickly and easily. IIRC it was added in firmware after release on the Agilent, and it's handy. I think it just measures the minimum observed pulse width (either positive or negative) within the captured data.

Feature request 1: bit rate measurement, please!

In the absence of an automatic measurement, I figured I'd just do it the old-fashioned way. Capture a packet, find the narrowest pulse and assume it's 1 bit wide. Then, put the cursors on the edges as accurately as possible, and measure their separation.

The odd behaviour is that the delta-X measurement on screen doesn't show the distance between the cursors if one of them is off screen; instead, it 'clips' to the edge of the screen, and if both are off screen then it just reports the width of the screen, or zero if both cursors are off to the same side.

That's really misleading. It clearly remembers the correct cursor positions if they're pushed off screen, because they come back to the right place if I adjust the time base to bring them back.

If I were feeling unkind, I'd call this a bug, though it's clearly intentional behaviour. I just can't think of any circumstances when I'd want to measure between a cursor and the edge of the display, as opposed to between the two cursors.

Feature request 2: delta-X time measurement actually measures the time between X1 and X2 even if one or both of them is off screen - not between a visible cursor and the edge of the screen.

(Example photos: both cursors on screen, showing delta-X = 8.01us, and the effect of just speeding up the time base 1 click; this pushes X1 off the left side of the screen, and the delta-X readout becomes 6.77us which is effectively meaningless).

7

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by seppeltronics on Today at 09:44:31 am »

Hello Reztek,

could you please share more details, how exactly did you do it?

- OS and version
- Type of network card
- IP adresses
- Call of the Script
- Log/Output of the script
-...

Thank you very much.

Best Regards, Seppeltronics

8

Beginners / Re: How to model piezo buzzer using LTspice

« Last post by jj5 on Today at 09:43:42 am »

If I know the frequency (3k, as above) can I calculate a series/parallel inductance?

Apparently the series inductance (L) is given with: L = 1/((2πf)^2 x C); where f = 3,000 Hz and C = 0.000000025 F; so L = 112.58 mH. Does that sound right to you?

9

Projects, Designs, and Technical Stuff / Re: (Yet Another) DIY Multislope ADC

« Last post by iMo on Today at 09:37:04 am »

..One can be more effective (faster and less need for integrator headroom) by also looking at the comparator for the initial up part:  go up for some 2 cylces past the comparator saying that the sign is right. One may need some minimum for the step to have more time for settling.  There are than mainly 2 cases, that can still be handled the same way:
a) a short up phase of the minimum length and than a possibly longer down phase for the end
b) a longer up phase and than only a short (e.g. 3 or 4 cycles) down phase, just to get the zero crossing from the same direction as in the case before..

So the key message here is to approach the "end zero crossing" always from the same side (for example from "positive side") in order to eliminate the "comparator hysteresis" errors.

The steps, for example, when talking PIO in this case, we want approach comparator always from the "positive" side:

0. runup ended, switch both Vref switches off
1. look at the comparator (2 SM clocks)
2. if comparator shows positive side - set Vref switches such the integrator's voltage goes down (1 clock)
3. count the SM clocks till comparator changes while crossing the zero (2 clocks per count)
4. send the count to MCU (1 clock)
..
2. if comparator shows negative side - set Vref switches such the integrator's voltage goes up (32 clocks)
3. switch Vref switches such the integrator's voltage goes down (1 clock)
4. count the SM clocks till comparator changes while crossing the zero (2 clocks per count)
5. send the count to MCU (1 clock)

Is that ok?

This has to fit inside the 9 instructions left..

10

General Technical Chat / Re: Boston Dynamics new Atlas Robot.

« Last post by BrianHG on Today at 09:35:33 am »

Looking at it, I would have to bet that the torso must be something like 75%-85% battery if they want to get some serious hours of work per charge...