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It will be a 50% duty cycle square wave with rise/fall times less than 100nS. =) Duty cycle in CW refers to how much of the cycle is active, duty cycle in pulsed mode refers to how many cycles per unit of cycles are active. So while CW is 100% pulse duty, it's 50% cycle duty.

Eh, in my very sleep deprived state right now I'm trying to mentally picture the current paths of the (faulty) arrangement with the diodes and predict if there will be a failure. I'm drawing a blank right now, heh, sorry. Instinct says it's probably ok as that diode arrangement would act as a...

Wait wait wait. Why do you have diodes between two gates? Definitely not good. I think you misunderstood Loneoceans' comment about diodes. You put the diode reverse polarity (anode to gate) across that particular gate's resistor. Let me see if I can ascii it for you: [GDT...

The optional diodes are the ones in series with the FETs. They are "safe" to omit, but they really don't have any negative (detrimental) aspect other than heating up the heatsink a bit more. If you omit them and run into the capacitive region, it can blow the entire bridge. The only significant...

Good to know, thanks! 1. I empirically found it stopped catastrophic bridge failure when driving capacitive loads. It isn't necessary and adds some cost/complexity, but in the seven or so physical iterations I've included it in there were no failures at all so I figure it's a safe precaution...

Too bad it doesn't merge them into a single trace for differential, but that pic shows what I needed. Driver looks to be fine. Now then, the next test would be to connect the GDT to the driver and scope the secondaries. This can be with the gdt disconnected or connected to the fets, as long as...

As long as one of the channels is inverted in that photo it looks fine. If one channel isn't inverted there we have a problem, as the two points should be out of phase 180deg. I'd still like to see a differential measurement where the channels are added but it isn't necessary. Here's the...

If the GDT isn't connected it can be powered indefinitely. The only issue occurs when there is a current path on the GDT output and the antenna input is left floating and susceptible to noise. The UCC chips self-resonate on the board at around 8MHz, which is well above their Safe Operating Area...

Looks like you have it hooked up fine in the photos. Power the driver with either the transformer or any 12V dc supply. The 555 board is electrically floating thanks to the battery, and you've made the ground continuous with the white jumper, so you're good. as far as scope math functions: you...

How's the color temp from it? I'd assume pretty warm being self ballasted and phosphored.

Realistically there are two options: 1) Run at resonance and adjust primary inductance to the desired current draw, adjust input voltage to the desired arc length. 2) Run above resonance (inductive region) to find an acceptable combination of output and current input. This stresses the bridge...

First thing is first for troubleshooting: Scope the Driver. Disconnect the driver from GDT, scope the output (use differential style, two probes no grounds, invert one channel and add both channels). You can use any signal that exceeds about 2Vpk to drive the antenna input of the driver. You...

Yep, by not grounding the "LV side" (bottom) you are inducing high voltage at it, and there will be a voltage differential between the windings nearest the strike ring and the strike ring itself. The bottom should be grounded or a large counterpoise should be used (5x coil diameter minimum), and...

Yep time to look at the driver. I'd wager the UCC chips might have gotten backlash and given up the goat. Disconnect the GDT from the driver, scope the output of the driver, touch the antenna with your finger to inject mains hum and you should see a nice waveform out. If there's not enough mains...

I think it all came down to the silpad he was using since it was (I think) excessively thick and of poor thermal impedance (high). Isolated individual heatsinks would be best but I don't think it's an option for him. He's had heatsink isolation issues since bridge 1.0, resulting in most/all of...

That should work fine, Benm. There are a few *really inaccurate* faux geiger-mueller apps for smartphones which do just this; relying on hot pixels to detect incident ionizing radiation. Also, I've blasted my iphone with 120R/hr for over 1min continuous while doing radiography. No damage or...

There should be no permanent pixel damage. People have put GoPros through electron beam irradiators (at thousands of R/hr) and had no damage.

Beautiful tube, what a score! Shame about the transformer though, those are nice to have working.

Very, very nice results! I'm surprised that camera performed so well. The hot pixels are because he's doing direct beam path imaging. If he used a mirror at 45-degrees to reflect the image 90-degrees off axis this will be eliminated, but it's often more trouble than worth unless the problem is...

You're very welcome! Glad you liked my packaging, haha, I take pride in making sure I do what I can to protect things I send out!