the Otherpower.com Discussion Board || Comments Two Stage Ghurd Super Controller

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Rants & Opinion - Diaries - Our Products

Two Stage Ghurd Super Controller | 7 comments (7 topical, editorial)

Re: Two Stage Ghurd Super Controller (3.00 / 0) (#2)
by wooferhound (tim((NoSpamAt))wooferhound.com) on Mon Jul 14th, 2008 at 09:42:40 AM MST
(User Info) http://wooferhound.com

Sure , I'll explain the Fan operation a little better . . .
If any one of the 2 stages pulses a dump voltage to the resistors, it also pulses the capacitor through an isolation diode, which charges up the 10000mfd capacitor and can keep the fan running for about 5 or 8 seconds. The the diode isolates the capacitor from the resistors preventing the capacitor from discharging back through the resistors. The ghurd dump controller can be set for a wide histersis range and I have mine set for .01 volt. Set that way the controller can pulse dumps quite rapidly. It is rare to see it pulsing dumps more than 1 second apart. I usually see the dump pulses running faster than 10 times a second, but it can easy be so fast that the dump light appears to stay on continuously.

There has been some discussion about how bad it is to charge a capacitor Hard like this in the first few dump pulses that may be more than 5 seconds apart, but I have never heard of any actual problems doing this, plus this is a fairly high quality cap.

W o o f -={(

[ Parent ]

Re: Two Stage Ghurd Super Controller (3.00 / 0) (#5)
by Opera House on Wed Jul 16th, 2008 at 01:50:59 PM MST
(User Info)

It wouldn't hurt to put a few ohm resitor in the charge part of that cap. A greater concern than damaging the cap is damaging a FET. A really good large value cap would look like a dead short and stress a FET that was operating close to its limit. I have used this method with higher frequency PWM dump and it is an easy way to turn on the fan as resistors start to get toasty. In faster PWM circuits, use a fast recovery diode otherwise it will be conducting in both directions.

[ Parent ]

Two Stage Ghurd Super Controller | 7 comments (7 topical, 0 editorial)

Menu

· create account
· How to use the board
· FAQs
· search the board
· Google search the board
· Old Otherpower Board

Login

Make a new account

Username:

Password:

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest © 2003 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!