need a rough idea of Neon Sign PSU output frequency modulation - Page 1
Forum section: electronics / general

author: Leland_Gaunt
author_rank: Contributor
timestamp: March 01, 2025, 10:05:59 pm
content: Hello gentlemen,i hope you can give me a rough rundown on frequencies maybe.I have a high voltage transformer, a neonsign PSU to be precise, that says "10KV 30ma" output. And "220V 400ma" input. Im using it to create a small arch not in a tube, but just in reghular air for a chemical experiment/reactor. I already opened a thread a couple of weeks ago with questions for my small scale birkeland eyde reactor and people already cleared some things up for me and helped me. I just dont think many people read it anymore, so i decided to ask this question in a more general form about the transformer.So the transformer works with 50/60Hz frequency, but it seems to put out app. 22Khz. Thats what i measure when i come close to the arch with my multimeter probes. I even can measure this in up to 1 m distance.However, im using it to create nitric acid i i already changed many other parameters that i can control in the apparatur, with the goal of getting the highest amount of HNO3/KW/h, pretty much everything but the characteristics of the arch itself.I came over a website where somebody with a more professional approach was able to experiment with different arch frequencies and he obviously had far better results with 10 Khz. The machine is entireliy different from mine, but still i would like to know about the frequencies.First. how does it even come that it puts out 22khz when its hooked to 50/60Hz AC? is that just a typical natural phenomenon of an arch, or is there any hardware in this PSU responsible for that frequency?Second, how can i change that frequency by myself? Would i need any hardware to hook between the electrodes and the PSU?I suppose there is no way to change the archs frequencies without new equipment?by the way, the transformers that i use are "Hyrite Lighting" NP-10000-30...and the real power usage is less than 50watt per arch, not 300W obviously.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 02, 2025, 01:55:23 pm
content: Most likely it's one of the modern "flicker free" switching inverters.

author: tooki
author_rank: Super Contributor
timestamp: March 02, 2025, 02:20:54 pm
content: Quote from: Leland_Gaunt on March 01, 2025, 10:05:59 pmFYI, it’sarc, notarch. (Arches are architectural features.)Anyway, you do not have a transformer; for the most part, neon signs stopped being powered by actual transformers years ago. For marketing reasons, neon power supplies are still routinely called “neon transformers” when in fact they are high-frequency inverters. But unless you have a box that weighs many kilos, it’s not a simple transformer.(Yours weighs 620g and claims to output 300W (10kV*30mA) while only drawing 96W from the outlet. For comparison, a transformer with the same output voltage and current weighs around 7kg.)Modern high-frequency inverters basically are an electronic circuit that uses high frequency to allow it to use a tiny transformer. These also typically have modern safety features like detecting an open circuit, short circuit, or if the current draw is outside an expected range. They are much harder to divert to other applications.Forget about modifying your unit; neon power supplies are potted (vergossen) for safety.Honestly, given your level of knowledge, I’m not so sure you should be experimenting with such high voltages. 10kV at 30mA is very, very deadly.

author: Leland_Gaunt
author_rank: Contributor
timestamp: March 02, 2025, 04:27:37 pm
content: Quoteas far as i have read, this is no "claim" for 300 watt, its just the maximum voltage and 30ma is the short circuit current.Also, how can it be 10KV at 30ma (very deadly) but only pull 96 watts at the same time? Its got a very low power factor and also pulls much less than that by the way, max 50-55 watts.i also never said or implied i want to "open and mod the unit itself" (insane and ridicolous idea).