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 #61406
Joined: Thu Jan 05 2017, 11:31PM
Location:
Posts: 268
Hi, it I've built this circuit but when the voltage reaches 9 volt on the capacitor, and the comparator must have switched. The comparator has a hysteria between 5_6volt. Would the circuit work as is, I'm trying to charge up a capacitor then discharge it. Thanks
Registered Member #2939
Joined: Fri Jun 25 2010, 04:25AM
Location:
Posts: 615
A sharp image would help. Better still go get one of the free SPICE simulators (e.g. LT SPICE, Simetrix, TI Tina) and use that as a drawing tool. You could also test your circuit with it ;) I use Simetrix - extensively.
Registered Member #2906
Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727
please attach the .asc as zip here. Note that A1, the schmitt trigger inverter, does have default values of 0V Low, 1V High at its output. i doubt it can drive the IRF530 in its default form. Have you checked that you get the voltages you wanted everywhere? If not do so! Also for better readability use "110k", instead of "110000" (the capacitor is "30n" for example). Then please simulate only the shortest time needed. The time step spice uses is somewhat related to the overall time - the longer you simulate the coarser the simulation by default..
Registered Member #2906
Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727
you made R2 "1m" which is 1 MilliOhm. If you want to make some thing MegaOhm, you need to write "1Meg" in spice. Again A1 issnt configured in any useful way. But besides that i cant really give you any advice. You still simulate for thousands of seconds...
Anyway, i looked at it, found some problems, but the overall circuit is a problem. the whole concept seems bad... i am honestly not sure what some stuff was supposed to mean... I suggest you build a block diagram, figure out each block and see if the signal do what they are supposed to do.. ]picc.zip[/file]
Registered Member #11591
Joined: Wed Mar 20 2013, 08:20PM
Location: UK
Posts: 556
Yeah, I agree with DerAlbi, and, as I'm sure he has noticed, one of your MOSFETs is attatched to a positive source, yet it is an N-channel 'FET. Change it to a P-channel one, and then feed it with the same inverted signal as the other 'FET. Then when the signal from the comparitor is low, you will get it inverted to turn M2 on and M1 off.
Please also redraw the bit with the MOSFETs so they are the right way up: that circuit is almost invariably drawn vertically, with M2 on the bottom and M1 on the top.
Registered Member #61406
Joined: Thu Jan 05 2017, 11:31PM
Location:
Posts: 268
Good advice. I've made the circuit more simple and also built it like the simple. Price in the built one the multimeter is showing 5.40volt across the capacitor, and I think it is working. I would like to have a higher voltage source charging the capacitor but it will fry the comparator, and how would people go about taking a ratio of the capacitor voltage, the voltage divider wasn't working.
Registered Member #2906
Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727
So you are discharging the 30uF through 200k and recharging it with a massive current pulse through he IRF530.with your 10u timestep, you might not see it, but this is kind of brutal. Please give M1 a 10R resistor on its source... its not mandatory, but good practice. Regarding the "higher voltage": wrong architecture. It would be doable by a PFET.. of course you need a small NFET and a resistive divider to drive its gate, but it would work.
Registered Member #61406
Joined: Thu Jan 05 2017, 11:31PM
Location:
Posts: 268
I've got this so far, I'm trying to get R5 below 10ohm,but it doesn't switch, I'm thinking there are multiple voltage dividers that stop it working. The gate to source, is close to 12volt. How would I modified the circuit to make R5 about 10ohm.
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.
Problem with comparator and switching
