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Cheap high voltage moduled on ebay

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LAN_403

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Sat Sept 05 2015, 11:01PM

Registered Member #54278 Joined: Sat Jan 17 2015, 04:42AM
Location: Amite, La.
Posts: 367

Does anyone know anything about those high voltage modules sold for about $4 on ebay. I bought some rated at 3VDC input at 7000V output. I put a diode on the output and it would actually charge a bank of those Maxwell (200lb?) capacitors 4kV @ 400uF each. FULLY in a short time (minutes). Also it charged a bank of three of these in parallel to the full energy.

Now many more similar modules have appeared: a few volts DC in to around 30kV out then 60kV out now I see 400kV out!
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I would like to know what kind of circuitry they use and the HV output waveform characteristics... The input requires a few amps.
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Does anyone have details on the output? In my option the 1st type, and cheapest--I've gotten some as low as $2 (3VDc to 7kV) appear to work most efficiency (less heat). Use a about a 3A DC adapter or a massive pair of D-type batteries!

Antonio

Sun Sept 06 2015, 01:12AM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

Probably simple flyback circuits. 400 kV is obviously absurd. 40 kV would be already difficult. There are some videos of these devices in Youtube. 20 or 30 kV at most.

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Sun Sept 06 2015, 05:43AM

Registered Member #54278 Joined: Sat Jan 17 2015, 04:42AM
Location: Amite, La.
Posts: 367

I agree at 400kV...a crock==I think the ebay folks have redefined the definition of a volt (J/C). Have you seen the 50 million volt stun guns. Just do an ebay search for "stun gun" I think the first thing you see is a 48MV flashlight stun-gun: about $8! ...don't know if any are below MV's.

****If anyone knows what is going on with these ratings please post!**** I like good proper use of units

I can't even find the good ol' fashioned 'Tesla circuit' stun guns anywhere!

If the voltage breakdown of air is 3MV per meter, then these little flashlights can potentially eject over 50 foot bolts!! Forget you pig-powered Tesla coil, just pull out your 1/2 lb pink stunner!

jpsmith123

Wed Nov 18 2015, 02:59AM

Registered Member #1321 Joined: Sat Feb 16 2008, 03:22AM
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I'm wondering, how rugged are these cheap HV modules? IIRC the ebay description warns against an unloaded output and/or a high duty cycle. Has anyone burned one up yet?

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Wed Nov 18 2015, 03:22AM

Registered Member #54278 Joined: Sat Jan 17 2015, 04:42AM
Location: Amite, La.
Posts: 367

jpsmith123 wrote ...

I'm wondering, how rugged are these cheap HV modules? IIRC the ebay description warns against an unloaded output and/or a high duty cycle. Has anyone burned one up yet?

I have never burned one out by open circuit induced HV ...never tried...I always used a spark gap for safety here. I have a few and will try it on one shortly--I bet those bigger modules will go out by overheating.

I sure wish I could get a schema or I/O volt/amp rating sheet on these. I am thinking of trying to depot one

..will post any obtained information...

johnf

Wed Nov 18 2015, 05:46PM

Registered Member #230 Joined: Tue Feb 21 2006, 08:01PM
Location: Gracefield lower Hutt
Posts: 284

most smaller DC/AC converters like these are remnants from LCD back light inverters and use a Royer type push pull circuit on the primary.
designed right these will provide an output voltage proportional to input voltage over quite a wide range

Sulaiman

Wed Nov 18 2015, 06:51PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

I have two types of these modules, no particular intended use but they were too cheap ;)
3 Vdc to 7 kV ... these modules are for tennis racquet type fly swatters, 2x alkaline cell.
... a must-have for junior experimenters or senior 'must get one just in case ...
P.S. so far (about five 'play sessions') no problem using a single 18650 lithium cell.

240 Vac to ?forgot? kV ... for ionisers
seems ok, not really measured it yet.
NOTE: I guess it is a C-W type multiplier, light, eht output is vs. ac input, capacitively coupled.
Mine has multiple paralleled output wires to what looks like carbon fibre brushes as ion 'sprayers'
tiny arcs can be drawn to fingertips from the brushes.

the '400 kV' I am not sure but I think that they are basically a cap dumped into a high turns ratio transformer
which gives the arcing or eht for a stun gun.
From what I've seen on the net, the transformers are amazing,
they saturate in a fraction of a second, but that is enough for the application.
The ones I saw were potted in bubble-free transparent something (epoxy I think)

P.S. forgot ... bullshit ! no way 400 kV on this planet at stp.

paris

Thu Nov 19 2015, 08:17PM

Registered Member #3042 Joined: Wed Jul 28 2010, 12:36AM
Location:
Posts: 121

do these chinese sell cheap x ray machines so as to see what the hv module components are in the potting?

kimbomba

Thu Nov 19 2015, 10:07PM

Registered Member #3854 Joined: Fri Apr 29 2011, 03:45AM
Location: Mexico
Posts: 95

Can these modules be connected in series for higher voltage, or in parallel for more amps?

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