If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #1054
Joined: Wed Oct 10 2007, 10:51PM
Location: Bulgaria
Posts: 29
Hi everyone, Currently I'm building a power supply for my large Tesla coil. I've modified a schematic I found long time ago (don't remember where it was from).
Here is the original:
...and the modified one:
My question is are the microwave oven diodes and caps suitable for this quadrupler or they will overload?
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
I originally designed this quadrupler circuit for use with one MOT. You're using two in series, so you'll get 20kV DC output. This will be too much for the caps and diodes, they will probably blow up.
Registered Member #1054
Joined: Wed Oct 10 2007, 10:51PM
Location: Bulgaria
Posts: 29
Hi again, I've made some changes on the schematic mainly due to the lack of MODs. Recently I have a lot of 1N4007 and decided to make four strings x12 diodes each. But even at low voltages (70-100V from variac) a light crackle sound appears and the strings (outlined in red at the schematic) are getting very hot and disassemble from solder. Later I figured out that only four of them have survived. Those outlined in blue have no problems - they stay cold. What may be the problem, are some resistors needed, I thought that using MOT as a ballast is sufficient?
Registered Member #1054
Joined: Wed Oct 10 2007, 10:51PM
Location: Bulgaria
Posts: 29
No, the output wires were separated away from each other. I started rising the voltage until the crackling sound started somewhere between 50-100V and then almost simultaneously the strings outlined in red fell apart. I did this as a first test without any load at the output, just to see the components' behavior.
Registered Member #2463
Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546
Your last circuit should have an earth ground connected (solidly) to the series connection joining the two capacitors and the core of the transformer.
If not, a flash over could launch a major transient back down the incoming power line creating unpredictable trouble. The bigger the capacitors, the more trouble.
Registered Member #1054
Joined: Wed Oct 10 2007, 10:51PM
Location: Bulgaria
Posts: 29
Yeah, the system is not grounded yet, I'm relying on the variac's circuit breakers to trip when such a trouble arises :D Aside of that I'm using one of the phases of a three-phase system which is tough to overload. But yet, is it possible the diodes to blow because of missing grounding?
Registered Member #2463
Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546
I used to work on Cottrell precipitator units. The diode sticks were made up of enough 1 amp diodes to provide 100 kv. They were in an oil bath, and each diode had a ceramic capacitor across it to distribute fast rise time transients.
The unit worked by allowing the voltage in the scrubber to build up until it flashed over, then built up again.
The control variable, sparks per minute, was achieved with a magnetic amplifier reactor in the primary circuit.
Occasionally, ground straps would break on the chamber. ( the electrodes were hammered by air rappers, to knock the soot clumps down). When the straps broke, there were sparks everywhere and the boiler operators scattered.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Question about double MOT quadrupler
