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 #32
Joined: Sat Feb 04 2006, 08:58AM
Location: Australia
Posts: 549
Tipp wrote ...
Aight, well I tried sample circuit #1, and the LED turns on, but the thyristor won't latch. Is this normal for a huge power SCR like this? I have a 5P4M SCR in a TO-220 package which latches normally when tested in this manner.
[Edit: Currently reading the wiki page, whoever drew those pictures has some mad paint skills ]
Maybe lightbulbs would be better for testing SCRs like this. That aside, your SCR seems to be okay and you seem to know how to make it go.
Regarding the wiki page. I'll just take that as a compliment.
If someone has a ready-made SCR testing schematic, having a copy on the wiki would be handy.
Banned Registered Member #110
Joined: Fri Feb 10 2006, 12:23AM
Location: Banned City
Posts: 85
You are using 5P4M? That part is under powered. 8Arms and 80A surge.
Here is a schematic that illustrates marginal holding current I(hold) for SCR. When testing mininum condition for Latching, all components Vsupply, Vload, and SCR voltage Von-state need be considered.
Example: For this SCR I(holding) = 80mA @24v. So why does this not work? 5vsupply - 3vled / 22 ohm(rlimit) = 90mA. The Led turns on but did not latch.
It worked after I factored in the on state voltage of the SCR, forcing me to lower the Rlimit.
Registered Member #215
Joined: Sun Feb 19 2006, 09:14PM
Location:
Posts: 30
Yeah, the 5P4M was for LED experiments
Alright, well, I finally got the sucka working. There were 2 very amatur reasons why it wasnt working, which I shall rate on a scale of stupidness from 1 -10, 10 being the most stupid:
Reason 1: The power supply. I was working with 9 volts at 2.6 amps from a wall wart. All was fine and good, tested it on multimeter to make sure it was outputting correctly etc etc. I decided to hook up a 555 timer w/ LED right quick to see if anything else was wrong with it. Well, got it all hooked up and BAM! Nothing happened I've done this a million times, why isnt it working? I go over all connections and everything looks good. I replace the cap just to be sure. Still nothing. Hook it up to 9 volt battery. Works perfectly. Ok, so it's something with the power supply...
After playing around with it some more, I decide to hook the supply to an inductor [i]. I hear a humming. Uh-oh. Can someone say non-filtered? A medium size [470 uF] cap across the V+ and ground, and suddenly the 555 works. Explanation for the SCR not working with the supply before: because it was so un-smoothed, the 60 Hz got through and was turning the SCR OFF each cycle. Duh!
Stupidness = 7/10. Should have known this beforehand.
Reason 2: Like mentioned above, I was only running 30 mA [for an LED] through it, when the latching current is 400 mA!! A quick change to a crapload of parallel LED's solved this no problem.
Stupidness = 9/10. This was stated right in the datasheet, I might as well be blind
Well, now that I KNOW my beautiful SCR is working, it's time to work on other components for the coilgun. Thanks all for your help! I owe you all milk and cookies
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.
Triggering SCR's
]
