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 #2881
Joined: Wed May 26 2010, 09:55PM
Location: IO70FC
Posts: 8
Hey found this design on the old part of the website and wonderd if anyone has attempted it.
Also could i use the following parts (some of the resistors arnt quite the same) as it would save me some cash having to use one of the bigger sellers.
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716
killerbanjo wrote ... Hey found this design on the old part of the website and wonderd if anyone has attempted it.
Also could i use the following parts (some of the resistors arnt quite the same) as it would save me some cash having to use one of the bigger sellers.
2.2m - 1N5408 Diode - I have a few 150uH inductors lying around so i will not need them.
Welcome.
The design looks like a standard regulated boost converter.
Your component value selections/substitutions are fine except for these caveats:
1) 2.2m, I hope you mean 2.2M. SI symbols and prefixes are case sensitive. And in this particular forum, megohms and milliohms are both practical units of measurement.
2) The diode must be "fast" according to your schematic, and I think the 1N5408 might not qualify.
3) You must figure the FET on-time, thus the peak current in 150-uH inductor. Inductor must be big enough to handle that current without saturation. Please read the MC-whatever datasheet and any associated app notes.
4) I am regularly disappointed that these designs don't show any capacitor between the input voltage rails, physically close to the inductor and FET. Not required if the input power supply is stiff enough and close enough.
5) I don't see C3 in your bill of material. Since you posted in the projectile accelerator forum, I presume you have a large capacitor bank. You should also have a small HV capacitor hardwired to the output of the boost converter, allowing the converter to operate normally (for testing and for its own protection) when not connected to the big bank. With no capacitive load, each cycle of the switcher produces a high enough voltage for something to break down (FET or feedback resistor or coil insulation), and I don't know how the regulator will react.
Registered Member #2648
Joined: Sun Jan 24 2010, 12:45PM
Location: Australia
Posts: 291
Hey
I'm working on an ic based cap charger at the moment too, Could you please post the specs on this? charge time? efficiency? cost? My capacitor charger costs about $20 each and can charge 2.5 milli-farad in under 5 secs (according to datasheet) from a 12v source (battery)
Registered Member #1667
Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 374
I have two remarks on this:
a) put 1..2nF + 10..22R in series parallel to the diode. This will make sure no high frequency ringing occurs (during both forward and reverse recovery). Overshoot is approx. I_reverse,max * sqrt(L/C)
b) try an intermediate circuit voltage, this will double the circuit complexity but eliminate the "low Rds(on), high voltage rating" limitation
Registered Member #2881
Joined: Wed May 26 2010, 09:55PM
Location: IO70FC
Posts: 8
Klugesmith - C3 is the cap bank, i have a 450v 3000uf cap. and thanks for taking the time to write that for me, a real help.
hboy007 - Thanks for your suggestions!
and GhostNull - I didnt come up with this schematic and i cannot find any specs however, the ammound of parts are so small that i think ill give it a go as it will only cost me a few £££ + £1.50 postage (I love bitsbox :D)
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Re the other comments, try a UF5408 diode instead of a 1N5408.
Also a decent-sized electrolytic capacitor ("decoupling capacitor") between the +12V and ground would be a good idea. 470 or 1000uF, 16V, say.
The industry-standard way to overcome the Rds(on) vs. voltage tradeoff is to use a transformer instead of an inductor, changing the circuit from a boost converter to a flyback converter.
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.
MC34063A DC/DC Boost Converter
