# high voltage

1. ### Earthed 12V Mains adaptor

Do mains adaptors with the DC ground connected to earth exist? / Where could I buy one? I am making a device which is powered from a 12V, 1A mains adaptor. The device has a high voltage DC module in it which outputs about 20kV. The way it is used, the high voltage is discharged into the air...
2. ### Insulation meter test. Is it OK?

Hi everyone. I got a new cheap 9-v powered insulation meter (250-1000V), just to see how it works, and if it fits my needs. I never used one before. I did a couple of test, and I wanted to share them, and also ask if you think the results are to be expected. The meter works fine when measuring...
3. ### Frequency of high voltage diode

Hi I want to buy 2CL2FM . http://www.hvgtsemi.com/upfile/pdf/2012110817253555456.pdf Trr =100 ns I want to find out the real switching frequency of the diode. Can I apply it in the smps with 100 khz of switching frequency? Regards
4. ### 120 VAC voltage detection

I'm working with a system that requires me to read 120VAC inputs on a pivot irrigation system. The wires travel 1/4 of a mile. Occasionally on the line I am reading, the voltage is 65VAC instead of 120VAC. I believe this is an induced voltage because of the length of the wires. I only want to...
5. ### Safe voltages and transformer secondary

I read many times, form many sources, that 60 VDC or 30 VAC are potentionally dangerous. I know that it is current what matters, but higher voltages lead to greater currents (assuming same resistance, of course). I also know that primary and secondary windings of a transformer are dangerous. But...
6. ### Doorknob capacitor substitutes

I probably need to replace a 16KV, 470pF doorknob type capacitor. They are very expensive, so I was thinking of putting 2x 10KV, 1nF ceramic disk type caps in series, which is much cheaper. Then my brain eventually ground round to the idea of hollowing out the original cap and putting the disk...
7. ### 60Hz transformer and Lichtenberg figures (fractal burning)

Background: A friend is looking to do some fractal burning (google it) (edit: also called Lichtenberg figure) and has salvaged a microwave oven transformer (MOT) for this purpose. However he likes to think big and isn't satisfied with the 2kV output so has asked me to look at increasing it. As...
8. ### My first tesla coil build

I've built my first-ever Tesla coil as a project and documented findings along the way here: https://siliconjunction.wordpress.com/2017/02/20/my-first-tesla-coil-slayer-version/ I'd really appreciate any suggestions on how to improve the circuit or writing Thanks a lot for your time Matt
9. ### Safety Warning

I hate procedures because they inevitably inhibit innovation and generally waste time with a load of meaningless waffle. But procedures are important. One area that worries me is electrical safety. Members, including me, often post schematics for circuits which involve dangerous voltages...
10. ### High voltage nanosecond pulse generator

Dear All, I would need for one of my research project a special nanosecond range pulse generator. This is very easy so far... But the output voltage for the generator must be in 20-40kV range! I have found some very unusual and expensive solution for this task, but I would need some relatively...
11. ### How does this Level Shifter with PNP Transistor Circuit Work

Voltage Source V2 is managed between 0 and 5V,So how does the voltage vary at point 4 or across the 3 ohm resistor
12. ### Electronic Tubes

I have a problem finding information on some tubed I have I have 6 big National Tubes NL-6989-NE The Tubes are new and because of their size I thought I could make some kind of cool display. The tube has a high voltage cap on the top and printed on the base along with the tube numbers is...
13. ### Tesla Coil Primary and Seconday

I must first apologize in the event I am breaking any forum rules with this question. I have been working on a rotary spark gap tesla coil for a few weeks and have stumbled upon the question of: does it matter if the secondary and primary coils are wound in like or opposing directions? By that...

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