Electronics > Projects, Designs, and Technical Stuff

Open HV Probe 40kV

<< < (10/26) > >>

mnementh:

--- Quote from: beanflying on April 22, 2019, 12:48:57 am ---And NO or BAD Knowledge is WORSE and even MORE DANGEROUS ;)
--- End quote ---

I'm not saying don't discuss... that's what we're doing here. What I'm saying is keep your dangerous prototype blueprints to yourself; an hour after you post them here, one of those crazy Russian house-burning nutbags will be printing one to hook up to a microwave oven transformer.

For sure, anything in this vein you devise that can be printed via FDM is just plain dangerous, for a dozen reasons we've described very clearly.  :-+

Cheers,

mnem
TEA time!

beanflying:
Breathing is dangerous in particular if done in the path of an oncoming Red Bus on Sundays  ::)

We will have to agree to disagree about releasing STL files as it offers a major safety improvement over what is generally available to individuals. How they get released should be in this thread stream (Not in the opening post) and with the express understanding that people have read the discussion to that point.

The enclosure is not dangerous but how it is used that presents issues. Letting the Gene pool only be exposed to bad solutions or really sub standard ones raises the risk of Electrocution. The King of Random's MOT infotainment  :bullshit: videos for example have multi million views  :palm:

mnementh:
Yeah, but you're talking about adding to the pool of BAD information out there.

What you propose is to release plans for a protective testing device that is inherently not fit for its intended purpose. To an uneducated public who has no idea how or why it's inherently not fit.  :palm:

Even if you make it and test it successfully, your test sample is far too small to reasonably declare it safe, for the same exact reasons as that fuckwit with his heat-shrinked resistors on a HFT Meter.

All for the sake of avoiding paying for a tool that is readily available on eBay for $30.

Please don't.

mnem
*Lit*

beanflying:

--- Quote from: joeqsmith on April 21, 2019, 08:29:01 pm ---A fun project to work on, especially if you want any sort bandwidth out of it.   

I made a few attempts at making my own KV+ low energy probes.  The last someone dubbed the burrito probe for some reason or another.    This repair video shows what it looks like today and I talk about some of what I would change if I make another.  Not sure it will be much help.    Good luck.     

https://youtu.be/kWOe803atvg

--- End quote ---

Really interesting series of videos and a lot of work  :-+ I will go back over them when I get around to the higher bandwidth option.

Did you completely stop using the Super Corona Dope and if so any reason? I see it is made up in part with xylene and a few other ene's but how does it stand up to repeated cleaning with IPA? I have found a localish source for not to many peso's for it so I can give it a test for adhesion on PLA.

Link to Super Corona Dope Datasheet
Australian Source

joeqsmith:

--- Quote from: beanflying on April 22, 2019, 02:56:14 am ---Really interesting series of videos and a lot of work  :-+ I will go back over them when I get around to the higher bandwidth option.

Did you completely stop using the Super Corona Dope and if so any reason? I see it is made up in part with xylene and a few other ene's but how does it stand up to repeated cleaning with IPA? I have found a localish source for not to many peso's for it so I can give it a test for adhesion on PLA.

--- End quote ---

I'm glad you are enjoying them.  The dope will come off with IPA and other solvents.  It can be easily damaged with a finger nail.  I clean the parts, then apply the dope.  I'm not aware of a better product for this sort of application and will continue to keep it in my bag of tricks.     


--- Quote from: beanflying on April 21, 2019, 10:06:37 pm ---One of the reasons to roll this probe was even a simple Calibration point of a 20MHz Scope last week was out of the range of gear I own. Having some bandwidth over a simple resistive divider would see it getting more use.

--- End quote ---

The response on my 40KV probe isn't very good.  It took some effort to tame it as well as I did.  Having the GDTs built in and using the two 40KV resistors (to handle a single point failure),  I have no concern about using it with any of my scopes.     

Of less interest, I did demonstrate a few simple low end, low voltage, low energy differential probes.  I don't think these were part of my HV probe playlist.  The last one I made on some perf board from scrap parts I had.   It's pretty funny to look at.   It does have some decent BW for being such a mess.         
https://youtu.be/0thOfk4I3qs

If you can keep your single ended probe within a dB from DC to 20MHz, I would say you have done a VERY good job!   

Beyond the obvious advice, like keeping parts CLEAN and keeping your source to a safe level a few things to consider.   While experimenting,  I suggest making some sort of protection circuits for when things go wrong.  No point in blowing a scope channel or your spectrum analyzer's front end.  Even some Citel GDTs and attenuators may save you a big repair bill.     Keep in mind what you want to measure in the future and minimize the loading effects.   While toilet paper rolls,  aluminum foil and other things laying around the house can look stupid, they can provide a lot of insight into how things will behave with little time invested. 

I followed this guy's channel until he stopped posting.  He did a series on AC high voltage probes as well that you may find of interest.   He was after a differential setup.   Here you can see them in operation.  The probes are the soup cans: 
https://youtu.be/cogG29Z7wrc?list=PLmj4qMKo6w6etRqmdffwfg9JqIeAR0tzL

Dave's friend also walked through an AC probe.  I attempted something similar to this but my skills were too lacking to get it to work as good as my toilet (shitter) paper roll and some aluminum foil.  :-DD         

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod