I would also add that the 1kV/mm rule for pointy electrodes work only until a certain voltage (45kV for needle in the chart), as it becomes non-linear after

I stumbled across this chart :
where 80kV gives 11cm striking distance for needles electrodes 

Hi everyone 

I found some cheap AC flybacks on aliexpress : https://m.aliexpress.com/item/4001091321165.html
they were featured in a video ( )
they must be used in oil / wax to avoid corona discharge

I would rather put this choke to earth, and the discharge tower directly to the bottom of the multiplier, or else the choke will arc over due to voltage peak

I did that, and it works great 

Edit : I left the secondary open circuit

Hi everyone,   
I'm concerned about the use of beryllium oxide in the white thermal paste commonly used for MOSFET, voltage regulator and power electronics
the question is, does it contains Beryllium oxide ?

edit : I always wash my hands after dealing with electronics

thanks for the replies, and good Xmas and New year

my bad, I completely forgot the resonant characteristics of these half bridge, where leakage inductance is welcome, focalizing on hard switched half bridge inverters 

sorry if my previous message causes misunderstanding

Hi everyone 

I recently made this tiny "high" (medium) voltage transformer, which outputs 690V rms at couples of mA, to feed small gas tubes and small multipliers

The transformer consumes 13mA when the secondary is open circuit, and 8mA when the secondary is shorted, with 0.1uF ballast capacitor in series with primary and isolated 230V in the primary.
When run for several minutes, the primary gets a very little warmer.



(the TO-247 mosfet is for size comparison, the core measures 5 cm height, and 3,5cm width)

the main  question is : Did you ever see an even smaller iron core (50-60Hz)  HV transformer, or did I make one of the smallest ? 

Hi

this cracking sound may be produced by film capacitor being  abused  by the high resonant voltage in this high current test

I would suggest you to measure capacitance before and after a run, to confirm or not if the cracking noise is coming from caps.
Indeed, when a capacitor is cracking, it loses capacitance a little bit, as the metal film is vaporized.

Have a great time 

Hi 

there is also a fifth type of core, although it's less common in appliances.

Indeed, I found some Metglas core in some appliances, like this core :
https://zupimages.net/up/20/12/xhah.jpeg

There is an overview of Metglas properties here : https://metglas.com/magnetic-materials/
Does anyone have tried this material for GDT, and is Metglas suitable for GDT construction?

Thanks 

Here in France, all schools, universities are closed, meetings of > 100 people are forbidden, some museums are closed.
Teleworking is encouraged, and at this time, there are 79 deaths and 3600 people are contaminated 

Hello 

I bought a similar flyback, it won't work for plasma ball as  it outputs DC voltage, and plasma balls requires (high frequency) AC to work.
Edit : I found on eBay an AC flyback : https://www.ebay.fr/itm/283635925903