Recent Posts

91

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by core on Today at 09:57:50 am »

But what kind of review do you expect Dave to do? In preparing a video, he cannot spend days and weeks to really dig into the subtleties of a device as powerful and complex as the 3000X HD. And his video format does not allow for the level of detail which Performa01 presented in his 800X HD thread -- nowhere near, in fact.

In this particular case I would like to know which FPGA has the SDS800 vs SDS1000 vs SDS3000 because they are all part of the same family, so as software they are similar, but as processing power I have no idea how different they are.

If the SDS1000 is just an SDS800 with a bigger screen, the price difference is not justified for many of us. About the SDS1000 we know what hardware it includes (user skander posted photos), but we don't know what FPGA and ADC converters the SDS800 has.

Same with the SDS3000. Unless it's significantly more powerful, faster than the SDS2000X HD, I have the same problem.

Also, it looks like the new SDS2000X HD, black, is coming.

Siglent is aiming higher than Rigol, and it would be nice to have more inside info (hardware) on these products. A review by Dave might help here.

Let's face it: The EEVblog videos are about entertainment, not about the in-depth assessment one would want to do before spending 5000€ and more. For professional customers, getting a demo unit would probably be the way to go. And for serious amateurs, at least in Europe, you can always buy a unit, test it for 2-4 weeks, and return it in case of major disappointments.

I'm not so sure about that.
Even though Dave doesn't always go into as much detail as we'd like, the work he does is VERY time consuming and the equipment he has access to for reviews is not available to all of us.

And the style he has covers a wide range of users. From beginners to advanced anyone can find useful and very useful information.

Unfortunately we can't find all the information in one place, we have to gather from several sources.

I don't like to order and then return the equipment. I prefer to have as much information as possible from the start.

And I wouldn't like to receive equipment already used as new.
If I don't like it, I'll sell it as second hand afterwards.

92

General Technical Chat / Re: Is VAT number needed when ordering from Arrow USA?

« Last post by EPAIII on Today at 09:52:58 am »

So, is it legal to sell to the public without paying the VAT? Or just harder to get caught without the VAT number?

Pardon my ignorance, I have never been to the UK. As I said, I am curious.

93

Beginners / Re: Convert US standard 115V to International 230V

« Last post by radiolistener on Today at 09:52:25 am »

Note that the op’s application involves equipment rated for operation at either 50 or 60 Hz, and the frequency conversion is not required.

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%.

If it really supports all frequency range which include both standard, then he can use 1:2 voltage transformer. But it requires that device needs to be carefully checked and tested in order to comply with both frequency standards.

94

Manufacturing & Assembly / Re: Vacuum Pick-Up Tool for Rework (Includes video of my own design)

« Last post by lamikr on Today at 09:50:43 am »

I added a foot switch-operated solenoid valve to an Aoyue 932, and am pretty happy with the result.

The valve and its power supply fit neatly inside the original enclosure. I added a barrel jack at the back of the unit for the foot switch. The hole in the handpiece is permanently sealed with a bit of tape.

I have the same Aoyue 932 and would like to do the same modification as the finger move to drop the piece makes the device for me less accurate compared to reverse
action tweezers. (https://www.amazon.com/gp/product/B07V8SLF2T/ref=ppx_yo_dt_b_asin_title_o07_s01?ie=UTF8&psc=1) I believe that with the foot control, the pump would however be handy for dropping components to pcb.

I have tried to search the internet but just found videos how to use the modded aoyue-932, but not any video or web page showing the modded device itself and exact parts needed for the modification. I do not know anything about solenoid valve pumps, never used one. I assume that it would need to be something called "2 way 3 position valve"? But even from those there are multiple control voltage options, sizes and whether to have normally open or normally closed one. So some help and pictures would really be appreciated :-)

95

Test Equipment / Re: SDS800X HD - Issue disscusions - is it me, or the scope?

« Last post by eTobey on Today at 09:50:40 am »

How about keeping the noise down, and trying to be professional? 
I dont see anything to discuss here at the moment. Except if you have found an issue that i have missed...

96

Power/Renewable Energy/EV's / Output Capacitor Selection for Buck Converter

« Last post by white_devil_123 on Today at 09:50:25 am »

Hey, I am trying to design a 24V/8V 8A Switching Power Supply at a 1MHz Switching Frequency with LM61480 Switching Regulator.

Here is the Datasheet to the regulator: https://www.ti.com/lit/ds/symlink/lm61480-q1.pdf

I have a doubt about the output capacitor selection. Can I use the usual formula, which is, "Cout = (peak-to-peak output current ripple)*(switching period)/(maximum allowable voltage output ripple)" for this switching regulator, too?

I did go through the datasheet but still confused.

97

General Technical Chat / Re: Russia and China to Build a Nuclear Plant on the Moon.

« Last post by strawberry on Today at 09:45:27 am »

one nuclear reactor is leaving solar system
high power reactor cooling in space will be biggest challenge because there is no way to dissipate excess heat
ISS use ammonia evaporator with ~70kW cooling capacity(i think)
most feasible colony options Total Recall 

98

Repair / Re: Agilent Infiniium DCA 86100C HDD image request

« Last post by ARF on Today at 09:37:45 am »

I'm still looking...

99

PCB/EDA/CAD / Re: High current traces meeting small component legs

« Last post by T3sl4co1l on Today at 09:32:27 am »

Ampacity only applies when the trace/wire is long enough that heat flow is entirely lateral, through insulation, into convection, etc.

For short wires and traces, heat flows along the length, and the bits at either end serve as heatsinking.

SMT packaging isn't especially conductive, but it's better than air, so heat spreads out within the package, and moreso where metal parts are present: leadframe, heatsink, etc.  Indeed, the wirebonds within the package are even tinier, and they handle amperes just fine. (Well, maybe not amperes each, but they might use a few in parallel, or thicker ones too.)

If you don't mind the voltage drop, and the heat can be dissipated effectively, there's essentially no limit to the current density you can put through a metal.  Signal size PCB traces can handle dozens of amperes for a brief time, hundreds even, before physical effects start to take over (at short enough time scales, skin effect takes over and cross-section can reduce significantly, and dI/dt * stray inductance can dominate to the point it arcs over instead; whatever the mechanism, see "exploding bridgewire").

As for pours, and especially when width exceeds length, ampacity rules completely go out the window.  Current itself isn't even spreading out evenly through such a conductor, and current density is concentrated near the pins, and in the region between them.  You could trim away all the material outside that current-carrying region, and get about the same total resistance, but ampacity would go down because the excess is still providing heat dissipation.

Better still: butt the components right next to each other, minimizing path length through PCB foil.  The best watt saved is the watt never dissipated.  If you can't arrange everything quite this close, consider adding current/heat spreaders to the design -- you can SMT chips of copper or brass, for example,

Tim

100

Beginners / Re: Looking for a SMD version of a U2008B

« Last post by pienari on Today at 09:32:12 am »

No luck with Rxelectronics.
Thanks for your kind inquiry.
It is regret to inform you that U2008B-MFPY is no stock and the product status is obsolete.

Im still waiting to Veswin reply.