Comments:
Brian Reid What will you do with 30kV?
Clara Sexton I don't know. Maybe build an electron microscope? I'll have to find out
Richard Sexton Don't look at me I'm just the programmer.
Clara Sexton A plasma torch.
Brian Reid Not enough energy in it. Many volts, but hardly any amps. The engineering purpose of the flyback transformer was to generate the signal that would cause the electron beam to "fly back" to the other edge of the screen and start the next raster line. But given that the transformer was there, some clever soul figured out that you could use it to generate the very high voltage needed to accelerate electrons towards the screen. Most transformers have two windings (primary and secondary), but flyback transformers in CRT displays have a third winding, whose purpose is to grab that flyback energy and make accelerator voltage out of it.
When repairing a CRT device, you can be seriously injured or even killed by the residual voltage stored in the anode capacitance. There exist "discharge tools" that bleed off that voltage, but if you aren't careful in how you use one, you can make the neck of the CRT explode before the stored charge is gone, which is an unusually bad thing.
In my youth I used to repair televisions to earn money. It was actually pretty dangerous unless you really knew what you were doing. Which I thought I did, and since I still have both eyes and am still breathing, I clearly didn't make any of the serious mistakes. The safety instructions used to include "Put one hand behind your back, so that if you accidentally touch a high-voltage area the current will not flow through your heart" and "Always make sure there is another person in the room with you to call an ambulance in case you make a mistake."
Richard Sexton I learned the one arm rule when working on servo amplifiers at Excellon.
"Don't touch those six shiny metal things"
"What are they"
"440 volts. They're the final stage power transistors to drive the half horsepower motor"
"better if you always keep one arm behind your back too so when you do tough them it only throws you across the room"
Also it turns out when you drive the opposite directions at full duty cycle once a millisecond they sort of explode.
Clara Sexton Here's a very small plasma cutter made from a lighter:
How To Make a DIY Mini Plasma Cutter From an Arc Lighter
Clara Sexton There's an instructable to build your own plasma cutter. It uses a microwave transformer
https://cdn.instructables.com/.../FGQNCQAGLFU0OP7.MEDIUM.jpg
http://www.instructables.com/.../How-to-Make-Your-own.../
Clara Sexton This uy used his flyback transformer to make special effects such as a Jacob's Ladder and Kirlian photography:
High voltage supply (10-30kV) made from CRT television flyback transformer
Clara Sexton A homemade arc welder in Rwanda:
"I was sitting in a restaurant in Musanze (small town in Rwanda) on Sunday and there were a couple of lads doing some fabrication work in the car park. When I saw their kit I just had to take some pictures. I looked at them, kitted out with cheap plastic sunglasses for eye protection, then their kit and crossed myself. They laughed.
Now I have a serious request. If anyone reading this has an old arc welder they no longer use at the back of the shed, then donating it to a Rwandan will give them a lifetime of work. I am back out here in Feb with 30kg of spare luggage allowance and I have a contact at an NGO who would be able to pass it on to a suitable recipient. I usually take clothes and even the odd manual sewing machine, it all helps. I've no idea how you would get it to me but we will solve that problem later. So if you are interested in giving someone the gift of employment, please get in touch.
Btw I'm not a scammer. I've lurked on this forum for years, mostly on the MIG side, but that sort of kit is way too complex!
Regards
Simon
Take a look at their kit. I watched them fix it after one of the cables caught fire and they just carried on...."
http://www.mig-welding.co.uk/.../2017-10-29-16-57-19-jpg.../
Clara Sexton A specialized spot welder for battery packs using a microwave transformer:
DIY Spot Welder
I needed a Spot welder for battery packs.
Most parts were found in my junkbox and this is what I came up with.
It´s based om a 1kW transformer from an old Micro wave oven and is controlled by Arduino Nano.
I plug in a foot pedal in the outlet to the left and set the welding time on the display.
I get a double welding pulse. The first for warming up and a second for the weld itself.
Nano can be reprogrammed direct from the front panel if necessary.
I´m no welding expert but it seems to functioning.
Jan Carlsson
https://www.facebook.com/.../a.758206.../855201771271592/...
Marty Michener I haven't seen or heard of a flyback transformer in 60 years. Wow!
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