that should work too, however I think that kerosene has shorter chains than mineal oil, so it's more likkely to burn than minearl oil
kerosene does burn, yeah
How do you measure HV?
it's one of the more commonly used EDM dialectrics though, so it's not instant death or anything
@guido.giunchi I do an indirect measurement:
trying to remember why I wanted to use it instead of mineral oil (which is also used)
I know what I have at primary because I can measure it with the oscilloscope
(I have 138V) and I know then exactly the voltage on secondary because I know the turn ratio
btw that's the transformer the machine uses
around 5kV on secondary
What about DC? You can use a huge resisitive divider, but that scares me if the ground disconnects or opens
@guido.giunchi i don't trust resistive dividers when I have to measure 70 000V xD
Yeah, I was referring to that!
I use the oscilloscope to measure the low voltage part of the circuit and do some maths
Also, simulations are helpful
I used OrCAD to simulate all the circuit
what about to measure lenght of the gab which the spark can jump? XD
@vincent stuchly you mean like this? :
Go and approach a ruler to it, if you dare
(I took that picture with the marx generator)
If I'm asking too much questions I'll stop, but I'm a curious electronics engineering student..
Why does the oil jump under HV?
(also it's my profile picture :D)
I know :D it wasnt meant serious I am sorry
@guido.giunchi the oil gets ionized, not by the multipler, but by the air
I mean, that does not happen in the sealed box
Doesn't it move inside the box?
Yes, it moves a bit
but there is no air (almost) in there
Looks like our time is almost up, but everyone is free to continue chatting as long as Fran wants to hang around, of course. I want to thank Fran for his time today and a really informative Hack Chat, and thanks to everyone for the great questions.
I also want to let everyone know that next week we'll be talking to Simon Jansen about "All Things Engima" - https://hackaday.io/event/163974-all-things-engima-hack-chat. Be sure to stop by.
so nothing happens
Can we hear about the CT scanner before we finish!!
I will stay :P
Yes, I prepared some things to show
This is part of the live fluoroscopy before I did the scanner
I wanted to know if the camera could record it
The white dots are just high energy photons hitting the cmos sensor?
I then took a motor:
@guido.giunchi yes, it's noise by the x-rays
The camera does record a bit of noise
It even records sound noise lol
I like that charger video!
This is the last video I prepared for this hackchat
A view inside the machine
This is how I do CT scans, to a lighter this time
btw, if you are looking to get some HV things to start doing experiments, here you have some things:
12v-36V ZVS Tesla coil flyback driver/Marx generator/Jacob' ladder+ignition coil 190268474092 | eBay
ZVS Tesla coil flyback driver generator/Jacob's ladder Inductive Heater ignitioN. 1 x ZVS Tesla coil flyback driver generator/Jacob's ladder Inductive Heater ignitioN. Excessive heat generated at magnetic coil. | eBay!
It's cheap and ready to use
On eBay you will also find HV diodes and capacitors like the ones I used for the machine
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=20kv+10nf+capacitor&_sacat=0 and https://www.aliexpress.com/store/product/High-voltage-diode-2CL2FM-100MA-20KV/931572_32768102085.html?spm=a219c.12010108.1000001.8.766770d6MVP1E6&ws_ab_test=searchweb0_0%2Csearchweb201602_1_10065_10068_319_10892_317_10696_10084_453_454_10083_10618_10304_10307_10820_10821_537_10302_536_10902_10843_10059_10884_10887_321_322_10103%2Csearchweb201603_59%2CppcSwitch_0&algo_pvid=9cf00a05-b59c-447b-83cf-bb12e925f0df&algo_expid=9cf00a05-b59c-447b-83cf-bb12e925f0df-7they are also very cheap:
sorry fot the long links
Also guys, any question you have about HV or x-rays, you can ask me anytime via DM
I'l probably reach out when I have a little bit more free time
Also one last thing, don't be afraid of failing
I did 3 transformers for the machine:
The first one died in 2 seconds, the second worked pretty bad, and finally the third was good enough
@Fran Piernas thanks for all the vids!
Keep in mind that there only one thing worse than seeing your device burning
And that's seeing that it does NOTHING XD
@Nevermore78 you're welcome :)
Ahahahahah happened too many times
Yeah, It also happened with the ZVS
I did two
this one never worked
very dissapointing, I was expecting at least that it exploded or someting
but nothing happened
Any last minute question guys? xD
what's your next project?
@Nevermore78 I'm buying the parts for a peltier based cloud chamber, I have the x.ray source, now it's time to build something to detect it
Woah, that's gonna be nice!
Yes, it should be much easier to do than the x-ray machine
well I'm leaving now guys, thank you very much for the chat!