Recent Posts

1

General Technical Chat / Re: Powering an LED from international line voltage

« Last post by kenyonshutt on Today at 07:06:33 am »

Capacitive Dropper may suit.

Looking into this more. So one drawback with this is that caps act linearly (obviously) so just a cap, series resistor, and LED would cause the LED brightness to vary depending on AC voltage.

I wonder if there's a way to set up a circuit like this...
line voltage - C1 in series - R1 in series - D1 in series - ZD1 to ground - C2 to ground - R2 in series - LED
with the intention that the C1 and R1 drop the voltage down to some 5 to 20 volts depending on applied AC voltage. then, through D1, that voltage charges up C2, limited by the zener voltage of ZD1, and then current from that is then trickled through R2 into the LED.

I do not know how to solve this kind of circuit on paper, so I might just grab some values and try it (keeping safety in mind).

Is this more complicated or costly than finding some dedicated HV linear current driver? *shrug*

2

Microcontrollers / Re: RIP Z80

« Last post by RoGeorge on Today at 07:06:25 am »

Found this, pointed by Hackaday, an open source Z80 in hardware:
https://github.com/rejunity/z80-open-silicon
https://hackaday.com/2024/04/28/the-z80-is-dead-long-live-the-free-z80/

3

General Technical Chat / Re: Powering an LED from international line voltage

« Last post by kenyonshutt on Today at 06:55:36 am »

How about use multiple smaller LEDs in series? Then you'll need less current for the same brightness, possibly to the point where a series resistor would become practical.

That's possible, but to keep costs low, I'd like to stick to only one LED. Thanks for the idea though

4

Test Equipment / Re: Hacking the Rigol MSO5000 series oscilloscopes

« Last post by BTO on Today at 06:54:28 am »

Okay, let's go over the moment of correctly installing Python and its modules; if at least one of the modules is not installed,
the script will not be executed at all, but we see that it is launched.

Here is the sequence I followed (according to your instructions):
1) installed firmware version 1.3.2.2
2) python rigol_kg2.py –i  xx.xx.xx.xx
3) python rigol_kg2.py –r xx.xx.xx.xx (we get an error, but the key file is being created)
4) python rigol_kg2.py     xx.xx.xx.xx
5) flash again firmware version 1.3.2.2
6) python rigol_kg2.py –i xx.xx.xx.xx
7) python rigol_kg2.py     xx.xx.xx.xx

Is everything right?

Not exactly, and as i suspected,  YOU'RE SKIPPING STEPS,
You've basically taken what i instructed and SUMMARIZED IT.   don't do that.
i we are going to help you, you have to follow the steps EXPLICITLY !!   You already have a problem  , skipping introduces more problems.

RE This

let's go over the moment of correctly installing Python and its modules; if at least one of the modules is not installed,
the script will not be executed at all, but we see that it is launched.

and.. No mention of what options you selected upon install python, You just SKIPPED to the part of installing the modules

Also, you didn't answer my question about zoom (i will therefore no longer ask, it will be upon you to ask if you want it now)

Now you stated 7 steps,  Mate in the PDF there are like 22 steps i think

but let's jump to step 3 in your list

3) python rigol_kg2.py –r xx.xx.xx.xx (we get an error, but the key file is being created)

OK, so if you got an error while creating the priv.pem  why did you proceed ?

but also, we didnt' get a screenshot to show any of this
Now re this

4) python rigol_kg2.py     xx.xx.xx.xx

You said that you ran  -r
then you ran  the script

HOWEVER IN YOUR SCREENSHOT IT IS CLEARLY SEEN THAT YOU RAN 
-r  then
-r
then the error happened

so like i said.... Start it all over again, Follow those instructions that i gave you.
Give us the screenshots, Each and everyone in a separate comment.  I know it's a pain, but it will help immensely and will get your scope
licensed correctly,   ARE YOU ABLE TO DO THAT ?

I want to help you, but at times you're being vague and not precise.
so far i've activated 7 people, its unlikely that your scope is different to their one
and another 3 or 4 people have just done it on their own without a problem, we only had 1 complaint , and that was valid
and that was that i forgot to include the step with the modules in the pdf,  i've corrected this

so..
we know the script works
we know the PDF works
we know our scopes are the same

the only 2 things that are variables are..
You... and Your computer

Are you able to try the process on another computer by any chance ?


Also... You know how you suggested there is a problem with the script and we should get DrMefist0 involved.
here is my opinion of what is happening with him
1. i reckon he's busy
2. i reckon he's see the post and isn't bothering because he knows there isn't a problem with the script.
Guys like DrMefist0 don't just jump in for any reason, but i reckon if there was a valid problem with the script, he would jump in and rectify it.

i reckon he's just waiting for all of us to troubleshoot through it, Exercise some common sense and work through the problem without him
getting invovled as there is no need to.
Again, Many others are doing it without problem.   this problem is isolated to you and we need to weed out what's going on.

Now, he wrote the script, Fair enough,  I know enough python to see what's in the script, but clearly he is more fluent at python that i am.
Not to say that i don't understand it though. but it's a pretty straight forward script to understand what's going on

ON ANOTHER QUICK NOTE and i don't know if this may benefit you, You can go ahead and try it as well.

as per the PDF, we are
Downgrading from 1.3.3.0  to 1.3.2.2
then we are applying the -r     then running the script
then we run 1.3.2.2  again
then we run the script again
and that activates it.

A USER BROUGHT UP... Why don't we just activate it from 1.3.3.0
Now.. there are downsides to this
THE MAIN BEING... when you do the full activation you end up on 1.3.2.2 and then you UPGRADE to 1.3.3.0 and you can see confirmation
that options survived activation.

I have not actually tried to run the script from 1.3.3.0  , MAYBE YOU WANT TO GIVE IT A GO, it can't hurt, Worse case,  it doesn't license it.
you've lost nothing
I'm going to try and give it a go in the near future, just to see what happens

so... I REALLY REALLY BELIEVE if you put in the effort to give us all those step by step screenshots

1. we can get to the root of the problem
2. it was ABSOLUTELY help others if they have the same problem

what are your thoughts

5

General Technical Chat / Re: Powering an LED from international line voltage

« Last post by kenyonshutt on Today at 06:49:05 am »

Single diode for half wave rectification, optionally a small capacitor to reduce flicker, a zener diode to cut off the voltage if it goes above around 200v DC or less (up to you where you want heat to be produced) , a HV linear current driver  like CL220 (5v - 220v DC, 20mA out) : https://www.digikey.com/en/products/detail/microchip-technology/CL220K4-G/4902728

Hey that thing is really cool- very much along the lines of what I'm looking for. thanks for the idea!

6

EEVblog Specific / EEVbog 1613 -Audiophile REPAIR: Chord Hugo DAC

« Last post by EEVblog on Today at 06:48:56 am »

Simple repair on the neighbours $4500 Audiophile Chord Hugo DAC.
Replacing the rechargeable lithium ion batteries wasn't quite as simple as expected though...
And is this thing worth $4500?

7

EEVblog Specific / Re: What's the keywords for finding a yellow spudger like Dave has?

« Last post by Brumby on Today at 06:45:35 am »

But if you take the picture and put a yellow and an orange line next to them you can clearly see that these are not yellow.

You could be making a fundamental mistake here.

Firstly, a lot of eBay photos are not properly illuminated, let alone correctly white balanced.  Yellow things looking orange is an easy thing to do.  Have a look at the last photo of the set and you will clearly see a yellow colour.  It does have an orange fringe, but that is what happens with poorly lit yellow items.

I have found that accurate colour on eBay is the exception, not the rule.  See here for more info on photography:
Re: How-to make decent photographs for forum posts/articles/publications?

8

Beginners / Re: AC brushed motor, caps & inductors

« Last post by NeilP on Today at 06:43:54 am »

Thanks
Yes, I took the brushes out, a very simple procedure on these motors, and did check/clean scrape between them.  All good there. 

This machine is 1940, one owner and I am thinking very little used

I’d suspect these are the original brushes too

I now have found a few diagrams of inductors and caps on motors, so does look a simple job. 
Just to settle on the values.

9

Altium Designer / Re: How do I edit lines in mechanical layer 1?

« Last post by Konsolkongen on Today at 06:41:43 am »

I see, that was actually pretty obvious

But there is no way to shrink or expand a shape on the mechanical layer then? As you can see in my image the board shape (the black area) has been slimmed a bit and made a bit taller too. I would like the mechanical layer to match. Am I correct that the best way to do this is to change the X/Y coordinates of the lines so they match?

I'm guessing I am so used to Illustrator that the handles and anchorpoints that appear when I select a line is throwing me off. I'm used to just be able to pull on these to modify the shapes

Another question. Do the Mechanical layer 1 represent everything that is being cut? I ask because I created a logo, also in DXF that I wanted to show up in copper on the top layer. In the gerber viewer this does look correct but the outline is present on both the Mechanical 1 and the top solder mask layer, and the engineer at JLCPCB was unsure if I wanted the logo cut out.

If I delete the outline from Mechanical 1 the logo still shows fine in the gerber viewer, so am I correct that I should just do that?

10

Other Equipment & Products / Re: QUICK 861PRO 1300W - Voice commands

« Last post by jwehle on Today at 06:29:35 am »

I'm also interested in this product and hoping someone can share their experiences.

Some random questions are:

  1) How useful is furnace mode?

  2) When cooling is activated does the unit actively ramp down the temperature so to minimize
      thermal stress (i.e. something like 4 degrees C per second) or does it just completely turn
     off the heater and depend on the thermal mass of the heater to provide a "ramp")?

  3) Do nearby lights flicker or does the unit have a sufficient filter?

PS: No interest in voice recognition ... turning it off will probably be the first setting I change.