Recent Posts

1

Beginners / Re: Checking an IC to be sure it's genuine and a not a fake/counterfit

« Last post by magic on Today at 05:29:45 am »

Yeah, that's what it looks like.

It is also common that there are many diodes from V- to various I/O pins and from I/O pins to V+ (in this polarity). If the other chips has power supplies on different pins (likely), none of that will match either.

2

Power/Renewable Energy/EV's / Hobby BLDC ESC snsor connections

« Last post by Circlotron on Today at 05:28:13 am »

Looking on ebay for a small electronic speed control for a PMSM with sensors. The motor I want to use it on has 3 sensors, so a ground wire and three others. Many of the sensor ESCs I have looked at seem to only have 3 sensor wires, red, black, white. Is this for a potentiometer connection instead? So how would connect three sensors? Example ESC ->  https://www.ebay.com.au/itm/315093498324?itmmeta=01HVQT2F6ED5QHD9GKQXH79FK0&hash=item495d0939d4:g:bv4AAOSwkz1lojwl&itmprp=enc%3AAQAJAAAA8MSg8sdXiwgJOAvXwOYbBAWlrRL93sAXiw3NYa4fA5r5cQ9Uki4fI6PpcXgkGaTaXxZwj5uWTMyT4YG4L%2BIXsKIFBWkthLR3G2NgAFypSxUn5TL8%2FUWSyV2%2BgSPQ7NWiNrzUvmrIRO5ACU%2ByJZCR9azgFr2GhZAABKm8JAFOXSr%2BHgU95sn5ZL9sHkd2Kpy8e2AwVwa3so5NRX7o8Wtuji21tr7d07GlY9xWfqOHxROQ%2Fp3NhKQr%2BnJQdSthmh94%2B5S6cymCXpwJ65JWNtuyrJJM5f0EwB3Kz9L%2FG0w153NoM5dw7TztgAAYL1xICRo5aA%3D%3D|tkp%3ABk9SR7DzifrdYw

3

Test Equipment / Re: Racal Dana 1998 blown fuse in BNC connector

« Last post by AVGresponding on Today at 05:26:25 am »

Mouser:  https://www.mouser.co.uk/ProductDetail/Littelfuse/0277.125NRT1?qs=Vv6sT79n3zTBYH3P4On6rw%3D%3D

4

Test Equipment / Re: Oscilloscope Music on DSOs- Post your Results

« Last post by Anthocyanina on Today at 05:24:41 am »

I recorded my demo by playing the youtube video into my 'scope.

I don't know if youtube audio compression would have any effect.


If anybody has an mp3...

Yeah, you need better quality. You can download wav files here: https://drive.google.com/drive/folders/1UHvGC6-TDywFri7am8YJl5G6svK33qhC

PC sound card to scope good enough?  Wouldn't think with audio, we need much?   Seems I tried it before with miserable results.   PC scope software out performed it by a mile.

i used my pc's built-in audio output for all the recordings, it's not bad as long as you don't use an equalizer or other DSP for your audio out

5

Other Equipment & Products / Re: Dymo 550 Thermal Printer DRM Hacking

« Last post by RethoricalCheese on Today at 05:20:36 am »

Ofcourse, happy to test.

6

General Technical Chat / Re: Migrating as a PHD student to US

« Last post by thermistor-guy on Today at 05:20:29 am »

...
$2000 per week/month/year?
And also where you live can make a huge difference in expenses.
Immigration issues aside, baseline problem is can you live on that money in that location?
...

A PhD in a STEM field, doing real research and advancing the state of the art, is stressful and time-consuming. It is a difficult challenge, intellectually and emotionally.

I suspect the OP will have neither the time nor the energy to work on anything else; side gigs for extra money will be out of the question.

7

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by Mechatrommer on Today at 05:19:39 am »

Adc is interleaved 0.8ns apart (1.25GSps) so it seems dso doesnt do built in deskew. Best to verify in 1X match length 50ohm environment, otherwise just deskew in setting whatever probes you have from same source.. older ds1054z you have to do mental deskew imagination in brain if it matters. Ymmv.

8

Buy/Sell/Wanted / SMIQ-06B front hardline

« Last post by drhex on Today at 05:16:42 am »

Hi,
Want to change my SMIQ-06B to front connection and the rear hardline can’t be just turned around - does anybody have a parts unit and can sell me the hardline only?
Thanks,
Florian

9

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by ebastler on Today at 05:16:16 am »

if you turn on three or four channels at the same time, the phase shift becomes about 20 degrees.

Why this happens is unclear.

There's only one ADC in the 'scope, shared between all channels.

When you turn on more than one channel you can see the sample rate drop.

Yes, it will probably have to to with the discretisation due to the limited sampling rate. The sampling interval is 1.6 ns or 3.2 ns (625 or 312 MHz sampling rate), larger than the observed skew of 0.75 ns.

Still, the scope should know if the samples are not acquired at exactly the same time, and correct for any offsets. And it is strange that CH1 is different from the others. Smells like a firmware glitch... Do other DHO800s show the same effect?

10

Beginners / How to model piezo buzzer using LTspice

« Last post by jj5 on Today at 05:14:41 am »

Hi there. I'm just getting started with LTspice and I want to model a circuit which contains a piezo buzzer. My FNIRSI DSO-TC3 component tester tells me that my piezo buzzer is a 21.6nF capacitor, so could I just model the piezo buzzer as a capacitor? I did try to search for information about how to do this on the web, but I couldn't find anything which I could understand.