Trying to make better vector HV boards.

mopar5150

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These are science experiments I am sharing with the guys that make their own vector monitors, not to replace original hardware. So AndrewB and Charles stop typing! :ROFLMAO:

Spent some time on the bench messing with HV boards. Because I have had some issues with getting enough focus voltage out of the aftermarket Amplifone flybacks, I modified one of Dezbez's boards to take a 6100 flyback.
I cut some traces and drilled the board for the 6100 FB then hand wired the flyback in. This works, and I now have enough focus voltage so that the adjustment is in the middle of the range. The phone photo of the Star Wars cab doesn't due the image justice.

I have also been working on a new HV board design using SMPS controller chips and MOSFETs. My goal is to eliminate the drive transformers from both the 6100 and amp, and remove the MC1 from the amp as well. The second set of photos is the MOSFET output stage hand wired to a 6100 board for testing. The design works, stays cool and draws about a 1/2A per supply.

I had to drive the MOSFET board with a function generator because I accidently blew up my little driver board (checked everything 3 times and still plugged the power supplies in backwards).

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Took what I learned with the last two board hacks to get some prototype boards made. Turns out that my SMPS chips are fake :mad: so I had to order some more from Mouser. Once they get here I will get some testing done.

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Took what I learned with the last two board hacks to get some prototype boards made. Turns out that my SMPS chips are fake :mad: so I had to order some more from Mouser. Once they get here I will get some testing done.

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Where did you get those counterfeit chips from?
 
Where did you get those counterfeit chips from?
It was an ebay purchase quite a while back. I am using the TL494 Because it can be used up to 40V VCC and I know the chip. It is outdated but still readily available.
I made the prototypes with a plug in control board so I can experiment with different control chips and methods.

If anybody has any experience with SMPS PWM and control circuits I am open to suggestions and ideas.
 
Finally got all of the parts in and did some testing. The base board with the drive and high voltage sections worked as planned although I did have to remove a diode I had across the FL primary (no Idea why I put that there). I had some issues with the little control board. Because I was using an extra filament winding as feedback for the control chip the chip wont start. This is because the short delay between power up and the flyback getting drive doesn't provide enough feedback and the chip shutdown. I was able to trick it into running by forcing the feedback signal and then the board made stable HV and video B+.

So back to the books to see how to get around the start up issue.

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Cool stuff! Back in the before-times, my first engineering internship was designing automotive ignition circuits for race cars.

Nothing quite like having a dual-energy system capable of melting the spark plug (100,000V before breakdown and 6A during discharge) running in the open on your desk. YOUR METAL DESK. :ROFLMAO: ⚡

This is basically the same thing, but with higher frequencies and bigger capacitors to produce DC instead of AC pulses. Show me a schematic and I can give you some ideas for startup control.
 
Cool stuff! Back in the before-times, my first engineering internship was designing automotive ignition circuits for race cars.

Nothing quite like having a dual-energy system capable of melting the spark plug (100,000V before breakdown and 6A during discharge) running in the open on your desk. YOUR METAL DESK. :ROFLMAO: ⚡

This is basically the same thing, but with higher frequencies and bigger capacitors to produce DC instead of AC pulses. Show me a schematic and I can give you some ideas for startup control.
100k at 6A will definitely kill you and hurt the whole time you are dying.

I will get the Kicad files updated and sent to you. I am out of my element on the control side and would appreciate any help you can give. I can also send you an assembled prototype if you want to experiment on your own.
 
Send me a pdf if you can….I don't use Kicad. (I should probably start.) I'm happy to take a look.

My lab isn't HV safe right now (or even 5V safe really). It's a mess while I move a bunch of furniture and boxes and equipment around. So you'd better keep the hardware. But maybe this will motivate me to hurry up with the lab rejiggering so I can play with lightning before baseball takes all of my time and energy away again.
 
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