Questions about High voltage transformers. - Page 1
Forum section: electronics / beginners

author: MrZwing
author_rank: Regular Contributor
timestamp: September 02, 2015, 10:00:55 am
content: HelloI wonder if these transformers could be used for some of my future experiments.I have pans to play with ions and tesla coils in some physics experiments and will need some high voltage and I also plan to play with both inductive smelters and manufacturing nano materials where I need a plasma arc.I wonder if this will be ok for my ion experiments.http://www.ebay.com/itm/DC-3v-6v-to-400kV-400000V-Boost-Step-up-Power-Module-High-Voltage-Transformer-/131527004748?hash=item1e9f9ed24cor is it better to try and fin for example a Neon sign transformer or a microwave transformer?or do something likehttp://www.ebay.com/itm/HIGH-VOLTAGE-POWER-SUPPLY-COIL-TRANSFORMER-Eleconic-Ignitor-tesla-coil-DC-PLASMA-/170929054061?hash=item27cc2a616dwork as well. I would actually prefer to have something complete due to safety paranoia but if I have to build something my self I would like to know a bit about these parts./MrZ

author: IanB
author_rank: Super Contributor
timestamp: September 02, 2015, 12:52:07 pm
content: "High voltage" is too vague a definition to define what you might need. You need to consider variables like the actual voltage, the available supply current, source impedance, regulation, AC or DC, adjustable or fixed output, and so on. All the same things that matter with any power supply.Depending on your application you will need to pick the specifications required and then match the supply to these requirements. Any single gadget that you buy is unlikely to suit all purposes.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: September 02, 2015, 02:17:23 pm
content: Whew....I've seen and commented (elsewhere) on that first item. "400000" Volts... that is, 400 kV.... ah, I don't think so. Notice that the specifications say:QuoteA spark across a gap of 20 mm between _large spheres_ in air at STP only requires 60 kV or so, and any other electrode geometry reduces the voltage required to arc across the gap. 400kV would arc across over 15 cm (150 mm) between large spheres and even greater distance between small spheres, points or wire electrodes.Also, there isn't much in the way of insulation that can withstand 400 kV in a small package like that shown. Distance is your only protection from that kind of voltage. Perhaps if you could separate the output wires sufficiently the unit might make something over 100 kV--- once.The second item will produce the 15-17 kV advertised but is designed for intermittent sparking use, not really as a power supply.A microwave oven transformer is _not_ current-limited and is _very dangerous_ to use as a HV PS, and "if you have to ask".... don't even try it. That is, working with HV sources capable of high currents is not a job for the inexperienced. Kill you dead, on the very first mistake you make.Most people who make their first spark-gap Tesla Coil will want to use a Neon Sign Transformer of 15 kV output or so, which is internally current-limited to 30 or 60 mA. These are still very dangerous if you don't know what you are doing.You may want to consider working with Flyback Transformers, which can be salvaged from old CRT monitors/TVs, for your early HV projects with ions/arcs. Induction heating doesn't require high voltages, but rather, high currents at high frequencies.You may find these videos (and others in my channel) of interest:

author: MrZwing
author_rank: Regular Contributor
timestamp: September 02, 2015, 06:17:21 pm
content: Hmm true I might need several types since I have several different types of projects so a "one size fits all" solution might be a impossible.I will do some proper research and see what I will need.Ah thanks for the vids I will take a look at them

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: September 03, 2015, 11:17:37 am
content: what ever you do DO NOT USE A MICROWAVE TRANSFORMER!!! THEY WILL NOT HESITATE TO KILL YOU!!! when i first got into electronics (about a year and a half ago) i took apart a dead microwave and was about to plug in the transformer, but noticed a big cap and diode and multiple "danger high voltage" labels everywhere so i decided to look up microwave transformers before i plugged it in. thanks to that google search i am still here today!!i attached a picture of the output of a mot (with a resonant cap bank)but if you want to use high voltage relatively safely, make a voltage multiplier (http://www.rmcybernetics.com/science/high_voltage/voltage_mult.htm) i also attached a schematic of a voltage multiplier.i hope this helps

author: Chris C
author_rank: Frequent Contributor
timestamp: September 04, 2015, 01:38:12 am
content: Quote from: MrZwing on September 02, 2015, 10:00:55 amBoth items you linked produce a pulsed AC output. For ion experiments, you'll typically need a DC supply. Hit your local thrift stores, you'll likely find a cheap air cleaner with a built-in ionizer module, which you can remove and experiment with. Failing that, you can get one on eBay, here's an example:http://www.ebay.com/itm/9VDC-Negative-ion-generator-9-5Kv-plasma-ionizer-high-voltage-mobile-module-9v-/181830886620?hash=item2a55f724dcThese are limited to less than 1mA, and perfectly harmless, unless you accumulate the charge using a large capacitor. The human body acts as a small capacitor, and if you charge yourself with one of these then touch someone else, they'll get a good zap as the charge between the two bodies equalizes. They'll also produce small but noticeable ion winds.Do NOT start off with the biggest, baddest power supply that will serve all your future experiments. You WILL make mistakes, and learn from them - but only if you survive. So start small, and get those mistakes out of the way while they're still survivable. Work your way up gradually.