Recent Posts

1

Power/Renewable Energy/EV's / Wrong crosssection of cables

« Last post by eTobey on Today at 09:53:03 am »

I have ordered cables from 6 different places (Germany). 5 of them had sent me cables that had about 20% less crosssection than advertised. I measured via visual and electrical methods, so there is no doubt about my measurements. One one ocassion, the outer diameter had me feel that it was to little, and sure enough it was...

Have you ever checked on the cross section?

2

Programming / Re: Angle wrapping in code, "easy" problem, need to double check

« Last post by electr_peter on Today at 09:51:21 am »

P.S. any tips on angle-wrap-respecting code to determine if a supplied angle is inbetween (on the short side) another two supplied angles? Imagine "spinning a bottle" and then checking if the resulting angle is within a certain sector, the sectors not all being equally sized or spaced, so it needs to be a genuine check of "is it between these sector limit angles".

This problem is trickier than simple comparison due to wrapping issue, but still easily solvable by splitting circle in two regions.
Lets say full circle has possible angles from \$0..360\$ (360 being same as 0).
Input is angle \$X\$ and sector from angle \$A\$ to angle \$B\$ (\$A>B\$ or \$A<B\$, i.e. \$10..350\$ (340 degree sector) is different from \$350..10\$ (20 degree sector))
Split circle in to two regions - \$0..180\$ and \$180..360\$. Based on \$X\$, select \$0..180\$ or \$180..360\$ region. Recalculate \$A..B\$ sector coverage in this region, to get \$A'..B'\$ sector with condition \$A'<B'\$. Then comparison \$A'<X<B'\$ gives the answer.

3

Repair / Re: Rohde Schwarz CMU200

« Last post by ON4GN on Today at 09:50:11 am »

Hello Harry_22.
Here are the photos from the CMU-B68.

4

General Technical Chat / Re: new propellantless drive company

« Last post by EPAIII on Today at 09:49:39 am »

I didn't see anything in that article that even gave the smallest hint of HOW it is supposed to work.

Like the EM drive,

https://thedebrief.org/nasa-veterans-propellantless-propulsion-drive-that-physics-says-shouldnt-work-just-produced-enough-thrust-to-defeat-earths-gravity/

this one uses a capacitor. Instead of piezo (not that a piezo is not a capacitor) , but it sounds similar. That is that there is some unequal force in a polarizing material which leads to thrust. Not a (weak) photon drive.

5

Projects, Designs, and Technical Stuff / Re: Practically smallest SMD size for assembly run of 1 to 100 pieces by PCBWay etc

« Last post by xvr on Today at 09:48:09 am »

Why not ask PCBWay directly? I guess they know what they do much better than EEVblog community.

6

EEVblog Specific / Re: EEVblog 1612 - Siglent SDS1000X HD 12 bit Oscilloscope Teardown

« Last post by rloc on Today at 09:39:07 am »

Dave, show us the PLL and the crystal oscillator manufacturer in more detail.

7

Projects, Designs, and Technical Stuff / Re: Accurate sine wave in terms of amplitude

« Last post by PCB.Wiz on Today at 09:38:51 am »

 What is the target distortion ?
If you only need a fixed frequency, a filtered square wave will be simplest.

8

Beginners / Re: Quickly Triggering Sensors - need an oscilloscope? what specs? (AU)

« Last post by xvr on Today at 09:29:34 am »

You need Pattern Generator. https://en.wikipedia.org/wiki/Digital_pattern_generator
https://digilent.com/reference/test-and-measurement/guides/waveforms-pattern-generator
Digilent Analog Discovery 3 -  https://digilent.com/reference/test-and-measurement/analog-discovery-3/start

9

Projects, Designs, and Technical Stuff / Re: Corrosion on DIP pins

« Last post by strawberry on Today at 09:25:15 am »

Not surprising, since the capacitor’s leads have to be made of a material compatible with its own electrolyte!

capacitor leads are tin plated iron (rarely copper)
tin solder tarnish at super high humidity level

10

Repair / Re: HP54600B with spike problem with and without signal

« Last post by fmashockie on Today at 09:22:21 am »

It is a private group so you have to request an invite, but you should at least be able to search through chat/forum history before getting approved.  And then you can make posts of your own. https://groups.io/g/HP-Agilent-Keysight-equipment