Recent Posts

1

General Technical Chat / Re: A serious (as in not troll) requestfor help w/ultrasonic transducer

« Last post by ebastler on Today at 06:11:44 am »

I don't have a specific product lead, but a recommendation for a company to contact: Sensor Technologies in Canada, a family-owned manufacturer of piezo ceramics and transducers. They were most helpful when I built a homebrew scanning tunneling microscope. (A long time ago, but the company is still run by the same family.)

Making a piezo element with a custom size is entirely possible, but would only make commercial sense if you need quite a few, I assume. But maybe they have leftover stock in a suitable size. The call the "donut" geometry a "washer" (or ring).

https://sensortechcanada.com/piezoelectric-ceramics/

2

Other Equipment & Products / Re: Crimpin’ ain’t easy (or: best hobbyist crimping tool/system?)

« Last post by bluey on Today at 06:09:06 am »

I don’t see anything about 50% off, but they do carry some JST connectors.

At least Misumi singapore has 50% for new users, for about the last year. https://sg.misumi-ec.com/

I used to get lots of stuff from Monotaro.sg, until they pulled the plug. Now only from monotaro in Japan via my Tenso mailbox.

19 JST tools under this listing:
https://sg.misumi-ec.com/vona2/detail/222000499301/

3

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by Performa01 on Today at 06:08:27 am »

One second of no feedback can be pretty long when I'm e.g. trying to adjust something. At 200 ms/div it's two seconds …

Sorry, but I cannot see a valid argument here.

I’ve rarely ever used a DSO to deal with very slow signals, but right now I’ve played a little with a 1 Hz cardiac signal, just to confirm my theory.

You want to adjust something. One would normally use a faster time base for this, so I have to assume that the repetition frequency of the event you want to “adjust” is pretty low – just like my 1 Hz cardiac pulse. Now I’m inclined to say that adjusting a waveform with a slow repetition rate will always be a pain, no matter how the DSO displays it.

If, for instance, I want to adjust the amplitude of the cardiac signal, I only get feedback every second, no matter what. And of course that makes it hard to adjust precisely, but please don’t blame the DSO for that.

I’ve tried both normal acquisition and Roll mode and for my personal taste, 1 second updates in normal mode are still bearable, whereas for 200 ms/div Roll mode might be the better option indeed – as long as you don’t need a stable signal position.

Now what would we gain from Scan mode?

Assuming 100 ms/div time base, we can say:
•   Normal mode provides a consistent snapshot of the signal every second.
•   Roll mode provides a consistent window into the continuously moving signal, without any blind time.
•   Scan mode shows an inconsistent mix of old and new data.

Scan mode certainly cannot speed up the update rate of the signal, and the adjustment process won’t get any easier.

Since display modes have to be implemented in hardware, an additional mode would take additional resources that (if at all available) would be much better spent elsewhere.

4

Test Equipment / Re: SDS800X HD Bug Reports + Firmware

« Last post by eTobey on Today at 06:08:12 am »

This is not a bug. Trigger and measurement are two separate parts.

I have edited the title accordingly. I was pretty sure that it was a bug, because it really "looked" like one. 

5

Other Equipment & Products / Re: Microscope Camera Best Option

« Last post by Vir1dis on Today at 06:07:41 am »

itscoldoutside where did you find info on what sensors are better?
What makes the 334 better than the 337 and 377?

6

General Technical Chat / Re: Do you think an LED is a resistor?

« Last post by BU508A on Today at 06:02:50 am »

A LED is not a resistor.

This is a resistor which can emit light:

7

Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's

« Last post by eTobey on Today at 06:00:37 am »

Imho, this is a feature.

My understanding of a feature in regards to a program, tool or software:
- Something that helps the user, like informations.
- Seome functionality that speeds up things.
- Some function you can do with a device.

Have not seen the use of the word "feature" for something that is bad  on a device.

Resources might be limited, so this i would consider normal behaviour.

8

Beginners / Re: Help identifying these possibly RF/Microwave components?

« Last post by Odd-Job on Today at 05:59:09 am »

Some of them look Russian to my eyes. The TriQuint box says 39 part, probably cut from a wafer, might be  I.C.
See if you can track down data sheets, people on ebay would likely be interested, if not you could try recovering the >>95% gold from them.

9

Networking & Wireless / Re: RESTORING EXTERNAL USB HARD DISC.

« Last post by Uunoctium on Today at 05:57:35 am »

You can try out "GetDataBack". If you can see your directory & data with the free test-version, it's necessary to buy the full version to save them. 79$
https://www.runtime.org/data-recovery-software.htm

10

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

« Last post by Odd-Job on Today at 05:50:49 am »

Hi am 1,
If you are expected to come up with an answer for your employer to fix this little problem, then all that is needed is a redesign of the primary winding's of your I.P transformer and maybe slightly more 'iron' lamination's.  If it is as you say 115 VAC @60hz with 20 A max then we are about 2.3 kVA worst case. 230-240 Vac will halve to 10 Amps so we are still around 2.3kVA. Suggest you get transformer supplier to wind   one with 2X120V windings that can be configured to be in parallel( 120 Volt 20 A) or series (240 Volt 10 Amps) either way about same kVA. Oh and make sure it is wound for 50 Hz so it will not overheat when humming @ 50 cps.
This is all said whilst assuming it is not a SMPSU in said unit. BTW is it a elephant defibrillator your involved in?
As Dr and us wrote;

It seems more logical to re-design the power supply itself instead of adding something to it.

Apparently it's already transformer based, so a different primary winding and a selector switch could be all that is needed.