Recent Posts

Pages: [1] 2 3 ... 10
1
The pulse discharge videos posted in this thread is a part of a series of explosive videos of old phones and electronics. The high voltage pulse capacitor bank, charger and trigger mechanism can be found with pictures, more videos and schematics here: https://kaizerpowerelectronics.dk/pulse-power/4000-joule-capacitor-bank/

A pulse discharge with a peak current of 50,000 Ampere is send through a Nokia 6230 mobile phone. A mobile phone from the era of indestructible handsets, a piece of electronics that would never let you down and yet here it is to die in a fiery explosion of hot-as-the-sun plasma discharge!

2
Sell / Buy / Trade / Re: LCR meter recommendation
« Last post by Mads Barnkob on Today at 08:23:57 PM »
Many years ago I just go by with one of the blue cheap Chinese LCR meters, but after Dave reviewed the DE-5000 LCR meter, I figured it was time for an upgrade. It has served me well ever since.

/>
Hi,

the best one I ever used was a HP4263B at my university.
However they are insanely overpriced even when broken.

I got myself a Deree DE5000 and I'm very happy with it.
It has proper Kelvin connections and a wide range of functionality.
I did some testing / comparing with other meters (including the HP) and was pretty surprised by its accuracy.

I tested the DE-5000 up against my broken and taped together blue Chinese LCR meter and was surprised that the cheap one was quite accurate as well!
3
Sell / Buy / Trade / Re: LCR meter recommendation
« Last post by Max on Today at 02:51:45 PM »
Hi,


I had to take a similar discussion some time ago and went for an HP4274A. It's a big, old unit but very handy to use. Every function has it's own button, no nested menus, well-readable, large 7-segment display, a range (1pF to 1F with 0.1% resolution) that's larger than the range of many more recent units and the speed is fantastic (~10 measurements per second or ~1 per second in HiRes mode). It also supports biasing the part (useful for electrolytic and ceramic capacitors which are voltage dependent). There's an option for integrated biasing but all devices support external biasing up to 200V.

You can get them "broken" for about 300$ (paid 330$ for mine plus shipping). However, many "broken" units aren't broken. The reason is that the unit shows "Error 4" if no cables are attached. Most sellers don't know that; they'll power it on, see Error 4, and sell it as broken. Of course, you can be unlucky and have a unit where Error 4 comes from actual damage. Service manuals with troubleshooting are available.
For 300$ there're not a lot of new LCR meters that are better than this - except for the size. You really need to have a lot of space for this thing.

I was lucky, I got a very clean, though slightly scratched unit and am happy with it. If you do get one, replace the infamous RIFA cap... it WILL exploded eventually.


Kind regards,
Max
4
Sell / Buy / Trade / Re: LCR meter recommendation
« Last post by Da_Stier on Today at 02:01:23 PM »
Hi,

the best one I ever used was a HP4263B at my university.
However they are insanely overpriced even when broken.

I got myself a Deree DE5000 and I'm very happy with it.
It has proper Kelvin connections and a wide range of functionality.
I did some testing / comparing with other meters (including the HP) and was pretty surprised by its accuracy.


Greetings,
Michael
5
Sell / Buy / Trade / LCR meter recommendation
« Last post by the_anomaly on Today at 01:58:48 PM »
Does anyone have a recommendation for an LCR meter?  Bench or handheld but I slightly prefer bench.  Primarily used for measuring inductance in the uH or sub uH range. 
6
I understand it now, it was just the missing link between your experiment being a replica of the subsequent experiment as A.M.Worthington describes as

Quote
"By wetting the surface of a smooth sphere we can always convert a smooth or "sheath" splash into a rough or "basket" splash. Thus when the ivory sphere (which when dry and well-polished gave, with a fall of 60 cm., the splash of Series XI, p. 97), was allowed to fall wet into the liquid, all other circumstances remaining the same, the splash of Series XIII, p. 103, was obtained, which is entirely different from the first. The wetting was effected by dipping the sphere into the bowl of milky water into which it was to fall, and then shaking off as much as possible of the adherent liquid, but in all cases the splash quickly became unsymmetrical, probably through the liquid, during the fall, drifting to one side of the sphere."

Just as Dave, I thought you replicated the hydrophilic/hydrophobic experiment, because from not knowing the papers beforehand, its counterintuitive that a wet sphere is going to act hydrophobic :)
7
That second paper makes sense.  Are you sure the "wet" and "dry" labels in the first video are correct.

The labels are correct. I got the same results as A. M. Worthington. He talks about it here:
https://www.gutenberg.org/files/39831/39831-h/39831-h.htm#Page_73

The paper you reference is talking about chemical processes to make different material spheres more hydrophilic or more hydrophobic, not the difference of a wet and dry sphere. But your experiment is to show that a wet sphere is the same as a chemically treated more hydrophilic sphere?
I was first trying to replicate A. M. Worthington's observation.

To improve your high speed video, you should get some 250W of LED lighting

The camera I'm using only gets 224 x 64 pixels at 1000 frames per second. I don't think more light will help much!  :-\

I could try to replicate your experiment with some more details on all the parts of your experiment. Its a little thin to just drop a video with no explanations...

I thought I explained my setup pretty well, what part don't you understand?
8
I am not quite following your experiment here.

The paper you reference is talking about chemical processes to make different material spheres more hydrophilic or more hydrophobic, not the difference of a wet and dry sphere. But your experiment is to show that a wet sphere is the same as a chemically treated more hydrophilic sphere?

To improve your high speed video, you should get some 250W of LED lighting, I build one myself from 5x 50W LED COBs ( https://kaizerpowerelectronics.dk/general-electronics/250w-led-flood-light/ ), that I use for high speed video recording :) I could try to replicate your experiment with some more details on all the parts of your experiment. Its a little thin to just drop a video with no explanations...
9
That second paper makes sense.  Are you sure the "wet" and "dry" labels in the first video are correct.  I'd expect the opposite.  I'd expect a wet sphere to behave more hydrophilic and the dry sphere more hydrophobic.
10
As a follow up, here is a link to a great little paper on the current theory about the sphere splashes:
https://www.nature.com/articles/nphys545.pdf
Pages: [1] 2 3 ... 10

* Recent Topics and Posts

post Exploding phones and electronics, a mini-series of 50kA discharges!
[Capacitor Banks]
Mads Barnkob
Today at 08:27:10 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Mads Barnkob
Today at 08:23:57 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Max
Today at 02:51:45 PM
post Re: LCR meter recommendation
[Sell / Buy / Trade]
Da_Stier
Today at 02:01:23 PM
post LCR meter recommendation
[Sell / Buy / Trade]
the_anomaly
Today at 01:58:48 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
Mads Barnkob
Today at 12:42:03 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
Today at 02:49:00 AM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
Mads Barnkob
June 16, 2021, 08:54:32 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
davekni
June 16, 2021, 08:00:50 PM
post Re: The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
June 16, 2021, 05:40:40 PM
post Demo Coil Protection
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
June 16, 2021, 05:39:14 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Twospoons
June 16, 2021, 10:20:30 AM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Patrick
June 16, 2021, 07:33:15 AM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
June 15, 2021, 01:21:38 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 15, 2021, 12:02:58 PM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 15, 2021, 06:52:56 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
thedoc298
June 15, 2021, 05:43:07 AM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
June 15, 2021, 05:26:34 AM
post The dramatic difference between wet and dry sphere splashes
[Science, Research and News In Other Fields Than Electronics]
haversin
June 15, 2021, 02:27:03 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 01:06:02 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 14, 2021, 12:44:31 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 12:41:33 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 14, 2021, 12:11:13 AM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 11:52:11 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 11:38:44 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 10:26:51 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 09:57:56 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 09:29:08 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 08:53:25 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 07:22:05 PM
post Re: First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 13, 2021, 07:02:28 PM
post Re: HFSSTC with fixed crystal-controlled frequency
[Solid State Tesla Coils (SSTC)]
Steve Ward
June 13, 2021, 06:25:20 PM
post First middle sized DRSSTC - Phase lead tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rapy2
June 13, 2021, 02:48:59 PM
post OpenTheremin v3 loosing calibration after minutes
[Electronic Circuits]
gianpaolo
June 13, 2021, 12:00:09 PM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Mads Barnkob
June 12, 2021, 07:28:03 PM
post Re: Rocket engine questions
[General Chat]
klugesmith
June 12, 2021, 07:23:12 PM
post Re: Rocket engine questions
[General Chat]
rikkitikkitavi
June 12, 2021, 12:24:06 PM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
Da_Stier
June 12, 2021, 10:06:18 AM
post Re: Rocket engine questions
[General Chat]
plasma
June 12, 2021, 10:01:29 AM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
Twospoons
June 12, 2021, 08:47:08 AM
post Re: What is the guidence on SpaceX rockets based on ? PID's?
[General Chat]
Patrick
June 12, 2021, 07:03:10 AM
post Re: Complications in the design of the first DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
PEDRO HENRIQUE
June 12, 2021, 06:42:56 AM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
davekni
June 12, 2021, 04:20:53 AM
post Re: SKM100 Mini DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Willsmith001
June 11, 2021, 11:08:24 PM
post Re: How much propagation delay is too much propagation delay
[General Chat]
Willsmith001
June 11, 2021, 11:07:00 PM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
Da_Stier
June 11, 2021, 12:33:55 PM
post Re: Nice PC Board Tesla
[Solid State Tesla Coils (SSTC)]
futurist
June 11, 2021, 12:03:24 PM
post Re: How much propagation delay is too much propagation delay
[General Chat]
davekni
June 11, 2021, 06:47:52 AM
post Re: How much propagation delay is too much propagation delay
[General Chat]
Power-Max
June 11, 2021, 06:32:02 AM
post Re: How much propagation delay is too much propagation delay
[General Chat]
davekni
June 11, 2021, 05:16:03 AM

SimplePortal 2.3.6 © 2008-2014, SimplePortal