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 #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
The 2SK2847 MOSFET 900V 85W RDS (on) 1R1 looks pretty handy - and I'd save the freewheeling components in the drain circuit and the 0R25 in the source feed too - no point in buying them all again, if you want to copy the useful parts of the circuit.
Registered Member #575
Joined: Sun Mar 11 2007, 04:00AM
Location: Norway
Posts: 263
Erlend^SE wrote ...
The board is also a (possibly good) way to drive the FBT, if you can figure out the circuit. Looks like you possibly can power the board "as it is" and get HV (b.t.w. it DO dislike sparks so best for eletrostatic motors, small lifters, and drive HV & CRT tubes)
The circuit as you have it on the board drive the FBT from 190V for the primary and 15V for the FET-driver.
If you use other drive-methods, you can quite easily messure the output voltage on that FBT by connecting pin 11 and 12 and messuring current toward pin 7 (HV return), beware of pin 15, it should be isolated properly if you don't want filter on the HV or connected to pin 7.
What state is the board in? all parts still on it?
Sounds like a very good solution, I would certainly try this.
fisrt thank you all for the help.. second i am still tying to figure out how to work with the flyback.. my problem is to undertand which wired i need to connect.. there are 3 red wires and one white. also i see 14 pins. i guess i need to give an input of a low voltage and i need to get an output of higher voltage. do i need to use also the pins? or just the wires? too bad i cant find a data sheet so i can learn how it works. i can see that on my board ,where i took off the flyback ,is written( VCP.G,30,-12,-120,ABL.900,40,G,GCND) mayb this can help finding out how does it work.. thank you all again.
i took another FBT from a Packard Bell screen.. again i didnt find the data sheet on google.. does any1 worked with this model or know where i can find this fbt data sheet? thank you its quite hard to work without a datasheet..
Registered Member #834
Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644
You will not find a datasheet. At most a schematic diagram of the connections, of the transformer alone or of it in the original board. By just looking at the connections in the board it's very easy to identify what the pins are, specially if you have the schematic of the board. The wires are all high-voltage outputs. The main output is obvious. The others are the taps of the potentiometers (not very useful due to the extremely high impedance). Of the pins below, you only need the ground connection, and the primary coil if you want to use it. Most people here prefer to wind another primary coil, to be able to use a low-voltage supply to power the flyback driver. About how it operates, search for "flyback circuit".
hello hello some little achievements.. i looked at this site: and tryed to find the coils of my flyback. as far i found some details as shown in the attached picture: i found one HV 0v output, and 3 input coils as i understood from this site: there is a primaty coil, a secondary and a feedback. the HV output included the 0v, i found. now how can i find the primary and the frrdback( as showen in the picture i found 3 coils in the input) also i did not understand how to find the primary polarity. the last thing i want to understand more how the drive circuite works.. the explenation on the last site was not so clear to me.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Antonio wrote ...
You will not find a datasheet.
I'd be surprised if it wasn't in back number of HR Diemen's "The Book" - [it shews up as an obsolete part] but if you've already checked that it isn't then you'll just have to sort it out empirically with a meter.
Registered Member #51
Joined: Thu Feb 09 2006, 04:17AM
Location:
Posts: 263
Edit: perhaps I posted this a bit too early, before reading the whole thread. If the original poster is just interested in learning how the transformer works and does not want to build a high voltage power supply then feel free to ignore the rest of my post! Thanks.
Maybe I don't understand what you want to do, but why are you even trying to identify the internal windings? The only things you need to find are the big huge wire comming out the top, and the return pin on the bottom. If you want high voltage, don't worry about the other windings. Even if you were given a diagram and information about turn count and gauge of each winding, you still would likely not be able to use the windings to build a driver that works on less than say 100v. Most flybacks are driven at about 170v, so the primary windings they contain are designed with a higher number of turns and are not designed to carry the current you need to push to obtain a decent power output at a lower voltage. Not to mention that if you drive a winding that was designed for say 200v at 24v or so your volts per turn will be so low that your output will be pitiful.
Forget about the internal windings and wind your own primary of 5 + 5 turns of 18AWG wire or so. Unless you know what you are doing and want to build a proper flyback converter, I would recommend you use the ZVS driver that everyone seems to love. It takes about 10 parts and will stand up to a huge amount of abuse! Also, you probably already have the tank cap and inductor from the monitors you have taken apart.
The original poster want to drive a flyback and to build a plasma speaker also he wants to learn a bit more what he is doing. so you say my input will not be the internal windings ? i thought this will be the input for the flyback.. i want to use the 555 component like you see here: (V-core) thank you all! :)
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.