Member postings for Jouke van der Veen

Why a FEM calculation?

I think magnetic permeability is an isotropic property. But I may be wrong, for “anisotropic” materials.

I think You made a FEM calculation to model your application but you used an isotropic value for magnetic permeability, just from literature. Perhaps we are chimpanzees, but not stupid. 😉

Interesting topic!

I would like to see a reference to software used to compare relative permeabilities of the different materials and as a result a list of these values. I assume it must have been rather a search on the Internet than a theoretical calculation.

Nice to read about a book of Frans de Waal about chimpanzee politics in this topic. Remember he is a Dutchman from origin! 😉

This is about aluminium, not brass. Keeping it in 100% oxygen will not do much. Air is already 20% oxygen.

You could also put the aluminium in boiling water which will make a dull surface. But clean it first thoroughly and do not touch it afterwards, otherwise you will get a “nice” stained surface from fingerprints etc. Try a test sample first.

Why destroying an alu surface by pickling?

I woud give it a (dull) anodising coating.

Or start with a light pickle and give it a anodising finish.

Joe,

I somewhere read in your topic that you found that the ball is oscillating in a more or less spherical motion. You already used a laser interferometer for that. So forget about my Michelson interferometer.

But I have a question. Could it be that stopping the ball from its “random” spherical oscillation needs more displacement (harder contact) than to start the ball oscillate again in a different mode when loosing contact? But then contact position should change by repeating touches, or not?

Jouke

Without deep thinking:

Submicron displacements to be measured by means of Michelson interferometry?

And that with monochromatic light (laser)?

Is this a variant of or improvement of the Foucault measurement mentioned earlier?

Jouke

Edited By Jouke van der Veen on 02/04/2022 10:58:26

Hallo Huub,

I watched your video.

I think it is very instructive and so complete. I have to watch it again to understand all the details.

One thing is quite clear to me. I will nether reach the level you present in your video although I understand your way of working.

In Duch we would say: “Dit gaat boven mijn pet”. But that is not the proper expression. It is above my level because of lack of practical capabilities and missing precise machinery.

I will watch your video again. Thank you very much.

Regards,

Jouke

Huub,

Thank you! I will have a look.

As I said before: when days get longer and temerature higher I spend more time outside, meaning that progress on gear cutters significantly slows down.
But now we get some winter weather.

On top of that I just recovered from covid-19, also not helping to make much progress on projects.

Regards,

Jouke

It’s all in the game.

I did some editing on the above text but it appeared not to come through.
It should be: Blaser is a well known Swiss company. And Blasomill.

Blaser is a wel known known company supplying all kinds of cutting (Blasocut) and milling (Blsomill) oils and emulsions worldwide. I remember the Blasocuts from my work. What type of Blaser oil should be used for tapping by hand.

Above I read about the “Dutch tallow”. I know, not much is blamed to the Dutch on this forum but this needed some research from my side. What I understand now is that it should be called “ditch tallow”. No blame for this mistake because the letters i and u are neighbours (at least on my keyboard). 😉

I have the strong feeling that the 25,000 hours “garantee” is only valid for the led itself and not for the electronics “in front of it” and necessary to let it emit light. 😉

Dave, thank You.

This was ignorance from my side how to do that, and not “rather lazy then tired”. 😉

Jouke

That is exactly what happened. The connector was bonded to the PCB already.

First thing I did, when I noticed that it partially detached, was re-bonding it with super glue and pressing the connector firmly down. Hoping that it would make electrical contact again. That did not work.

Then I undercut the connector with a thin wire saw, only half and there where no contact was. Then I could open the gap and melt a bit of solder on the metal parts. Pressing it together while the solder solidified. That worked. Finally I put some super glue around the connector foot. But I have only hope that this will lat long.

Thats why I try to find a replacement connector identical to the original and not to modify the housing of the dustbuster. They must be on the market, somewhere. If this is not a solution at the end then I will make alternatve connections.

Waiting for somebody who recognizes these soldered connectors with 2 parallel pins.

I think the black connector is a standard component. I thought I can find this on the Internet, but no.

Last year I have done all the nice catalogs with electrical and electronic components away because Internet is there. Somebody (SWHO) was complaining about books taking space on my(!) shelf. Thats why.

It is the DV215EL H1 7.2V.

in principle I do not need the complete PCB but just the black connector on it. Soldering it on the PCB is no issue.

I can find all kinds of power connectors for PCB’s but not this particular one with parallel pins perpendicular to the PCB.

Therefore I am asking for a name or code so that I can do a better search.

Regards,

Jouke

What is the official name/code of such a 2pin PCB power connector?

Somebody knows?

Our Black & Decker Dustbuster had difficulties with charging. It appeared that one of the two connections between connector and PCB was broken. I was able to repair it by some re-soldering between connector bottom and PCB and then quiclkly pressing down the connector before the solder solidified. It worked but for how long?

I was looking on the Internet for a replacement connector but I can not find it. I found the connector for the co-axial plug but not the connector with the two parallel pins (please, look in my album)
Is it typical B&D that uses the power adapter with the two parallel connections?

Regards,

Jouke

In Dutch we say: “liever lui dan moe” or in Engish: rather lazy than tired”. 😉

LED’s in the ring must be connected in series, therefore required voltage is higher than, let’s say, 3.3 Volts.

You read 12V on the output of the “power supply”.

Be careful and stay save. I would place the tiny white box with that tiny PCB and CE-mark on it in an earthed box and still then you can not be sure that 230V will never escape from that. Primary and secondary tracks on that tiny PCB are not far away from each other I expect.