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Registered Member #62265
Joined: Sat Apr 28 2018, 11:26AM
Location:
Posts: 24
@Plasma @ritaismyconscience
I've employed TVS protection (15V) from gate to source on the MOSFET and also at the battery, and I've increased the capacitive reactance at the voltage multiplier by replacing the 10nF capacitors with 1nF capacitors. I'm now getting 60mm sparks and the setup seems quite stable. Thanks guys. Short vid:
Registered Member #195
Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111
you should use a ZVS driver. you can get them on ebay or amazon. just google "ZVS driver" after you build one of these for your marx you will not go back. you can also go dual flyback and set your cocroft to be negative and positive and have them apose. I just made mine and added tranzorbs to the gate and Gate Emiter
Registered Member #62265
Joined: Sat Apr 28 2018, 11:26AM
Location:
Posts: 24
teravolt wrote ...
you should use a ZVS driver. you can get them on ebay or amazon. just google "ZVS driver" after you build one of these for your marx you will not go back. you can also go dual flyback and set your cocroft to be negative and positive and have them apose. I just made mine and added tranzorbs to the gate and Gate Emiter
Yes I'm moving that way... just having fun along the way. I have a couple of ZVS drivers, and I've been playing with TVS protection on the gate of the cheapo driver before I move on to the ZVS+LOPT. I've also been playing with opposing Marx generators to get half the PD to earth and so reduce corona losses. I suspect my capacitors may not be up to the job though... the Chinese advertise them as 1nF 20kV ceramics, but it's evident from one or two of them that they've been re-dipped, and that makes me wonder if they're not quite as advertised. I've already blown a few of these and that's before I go down the LOPT route. I suspect I may have to make up high voltage capacitors from series strings of polypropylene capacitors. Thanks for the feedback.
Registered Member #62265
Joined: Sat Apr 28 2018, 11:26AM
Location:
Posts: 24
teravolt wrote ...
you should use a ZVS driver. you can get them on ebay or amazon. just google "ZVS driver" after you build one of these for your marx you will not go back. you can also go dual flyback and set your cocroft to be negative and positive and have them apose. I just made mine and added tranzorbs to the gate and Gate Emiter
Yes I'm moving that way... just having fun along the way. I have a couple of ZVS drivers, and I've been playing with TVS protection on the gate of the cheapo driver before I move on to the ZVS+LOPT. I've also been playing with opposing Marx generators to get half the PD to earth and so reduce corona losses. I suspect my capacitors may not be up to the job though... the Chinese advertise them as 1nF 20kV ceramics, but it's evident from one or two of them that they've been re-dipped, and that makes me wonder if they're not quite as advertised. I've already blown a few of these and that's before I go down the LOPT route. I suspect I may have to make up high voltage capacitors from series strings of polypropylene capacitors. Thanks for the feedback.
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