Recent Posts

1

Beginners / Re: Calibration - How to Mathematically

« Last post by MrAl on Today at 01:39:08 pm »

Hello again,

Just to note, there are more numerical interpolation methods than there are stars in the sky 

2

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

« Last post by iMo on Today at 01:34:35 pm »

@NNNI: I've been interested in a deeper understanding of pros and cons of the rundown+auxADC alchemy as well, therefore my playing with the code and tables..

Your hw is ready for the experiment with that combo, so you may try. I think the key message here is the auxADC is of less "quality" than the rundown process, therefore anything which would "de-load" the auxADC helps.

My main concern are the various coefficients you have to get somehow and apply "accordingly" to all those elements such you get a result..

3

General Technical Chat / Re: Why Circuit Breakers DON'T Protect People (electric shocks)

« Last post by tom66 on Today at 01:34:03 pm »

RCDs also prevent fires.  One of the original justifications for RCDs was detecting rodent damage to tasty cables.  A rodent could chew through a cable and create a path from live to earth which might be insufficient to trigger an MCB but the imbalance would quickly trip an RCD.

This is a particular issue in lofts.

https://www.electrical-installation.org/enwiki/Protection_against_fire_due_to_earth_faults

4

Security / Re: Microsoft repackages apps with a telemetry .NET wrapper

« Last post by RoGeorge on Today at 01:32:10 pm »

This is not a surprise from them, remember the keylogger from Microsoft, in Windows 10?
https://www.pcworld.com/article/423165/how-to-turn-off-windows-10s-keylogger-yes-it-still-has-one.html

It was all official, a keylogger and more (speech input spyware) inside Windows, for telemetry and such, and you were agreeing with that in the EULA.  With reassurements that the collected data is anonymous and for your own good, of course.  So, not for spying, only to give you a "better experience" in the future. 

5

Repair / Re: Nichicon Electrolytic Capacitors leaking - common problem? ( Rifa X and Y also)

« Last post by Zenith on Today at 01:28:03 pm »

Im in the middle of recapping the P/S on an HP 8080A. Found all the rifas but still something wrong... test pins at the p/s are all reading correctly (A = 11.8v,  B = 5v ~ 1.8v saw, etc.) but nothing at the multicon. Hoping someone has a schematic or a link.
THx!

Almost all HP manuals are easily available on the WWW. I'd be surprised if this wasn't.

If you are very unlucky it will be a PSU HP bought in from another company, and the schematic isn't available.

6

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

« Last post by eTobey on Today at 01:19:26 pm »

New issue:
Wrong measurement:
X2 of the measurement should be, where the arrow points to (last rising edge). When i move gate "B" just a tiny bit to the left, then the measurement is rendered invalid. The measurement is also rendered invalid, if i put the upper level of C3 above high level of C4 (slightly under it).

To me it looks like a bug.

7

Projects, Designs, and Technical Stuff / Re: Vacuum Fluorescent Display Driver

« Last post by bostonman on Today at 01:17:15 pm »

I'll check with a scope.

I read that thread. personally I'd like the path of bench testing the VFD solo as a second step rather than risk damaging it (assuming it's not the culprit).

Since the fourth and fifth digit work sporadically, my assumption is: this isn't a short in the VFD. Before it seemed the fourth and fifth digit was failing around >15MHz, but then it began working correctly. Sometimes the display would show the frequency in ten or maybe eleven digits, other times the full twelve; but it was always the correct frequency (ignoring the in correct decimal and comma locations - at least I remember/believe they were wrong).

The only consistent error is the 12th digit segment C (?) remaining illuminated. Maybe periods/commas, but I believe those shift too.

8

Test Equipment / Re: Micsig Current Probe CP2100A/B Tests and Comparing

« Last post by ceut on Today at 01:16:26 pm »

I have made a little battery module for it, with a very lowcost powerbank module MH-CD42 and a switch+capacitor at the output: it works great 

Also, some last tests I have made with my Keysight DMM  (U1233A)

As the Keysight DMM have many hidden settings, I have activated the "Scale" mode with x10 attenuator=>so it shows the good reading with the Micsig on the input 
(The bargraph shows the real input voltage, and the "Scale" mode convert it on the main display, with the scale we choose in the settings)
No need to think at all

All with my RD600P PSU short cutted, and "0" done before the first mesurement.
I have to say that this Micsig is really super accurate 

9

General Technical Chat / Re: Is LinkedIn worth keeping?

« Last post by hans on Today at 01:15:44 pm »

Okay then, so probably my best bet is to ignore the feed, InMail spam (you can turn that off), don't add recruiters as contacts, and only log on when I need something done.

I've now hibernated my account to see if I will use it in the future. I'm actually going to jobhunt within now and a year probably, so lets see if I can do it without.. That would be final nail for me, as my gut feeling is still to get rid of it but only if that's to no (real) disadvantage

10

Projects, Designs, and Technical Stuff / Re: more modern version of tl494?

« Last post by coromonadalix on Today at 01:12:07 pm »

even at 1kw   ...  lots of things are involved    input stages,  PFC  if there is,  main power section ...

not a project for beginner