Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th July 2009, 02:38 AM   #21
Renron is offline Renron  United States
diyAudio Member
 
Renron's Avatar
 
Join Date: Jan 2007
Location: Sacramento
Found'em.

Thanks for not spoon feeding me........again.
I do appreciate the tip on the caps being film. You were RIGHT!

Metalized Polyester Radial Lead Capacitors made by CDE.
Non polarized, non inductively wound. Perfect for this.

I just needed a hint on where to look.

I love this group of folks, very knowledgeable and helpful, always willing to share their experience.


Cviller, better learn to eat with chopsticks.

Ron
__________________
"If it doesn't work properly, hope it catches on fire"- Nelson Pass @ BA3
"I fired up the prototype. Literally." The Prophet Pass.
  Reply With Quote
Old 24th July 2009, 02:53 AM   #22
grenert is offline grenert  United States
diyAudio Member
 
Join Date: Jan 2008
This is really a Norcal thread (cviller, I'm just on the other side of the hill from you)! Maybe we'll get to meet at BA.

Quote:
Originally posted by cviller
Cool article - I just skimmed it briefly, but it seems like he is looking at a single diode (half wave). He tries to justify that his calculations holds for full wave rectifiers too and he is probably right.
Good point. I never noticed that. He does discuss (at the bottom of page 7) comparison with a full-bridge rectifier, and I think he would say you only need the snubber RC across the whole bridge. I guess that the characteristics of each of the four (or two or however many) diodes and of the transformer are the same, so perhaps snubbing across all of them should be as effective as across each one. Of course, it would seem that snubbing across each diode would also be fine.

Quote:
Originally posted by Renron
Thank you for taking the time to answer my (probably) foolish question.

I found some other stuff too, a 100V poly cap from Panasonic which, after I looked up the specs. led me to a table of "Permissible Voltage (RMS) in Alternating Current Corresponding to DC Rated Voltage". This particular unit I have is rated for 63V RMS Alternating Current. I had no idea capacitors other than nonpolarized could be used safely in SOME A/C applications.
[/B]
Not foolish questions. Trust me - I do not know much myself. I don't understand your statement about polarized caps in AC circuits. You CAN use polarized capacitors to block direct current, such as in the input of a preamp, allowing alternating current to pass. However, off the top of my head I can't think of a power supply scenario where you would be able to use polarized capacitors with AC. From the table title, it sounds to me that it's referring to some de-rating of voltage when a NONPOLAR (your poly cap is nonpolar) cap is used with AC. The specified voltage rating is probably for DC.

Quote:
Originally posted by Renron
As long as I am pickin' yer brains......
What does the P mean?
I presume this is a film cap. yes?
Definitely is a film cap. I'm not sure what the P means. The K is a tolerance mark. Perhaps the P is a manufacturer marking for the type of film used?

cviller, sorry about all of the off-topic here.
  Reply With Quote
Old 14th September 2009, 11:14 AM   #23
sekess is offline sekess  United States
diyAudio Member
 
Join Date: Feb 2006
Location: NJ
Default Heatsinks

Hey Christian,
I was thinking of using TO-247 rectifiers on your boards. You gave a reference for a heatsink in your first post.

2 questions:

1. Will the heatsinks that you referenced accept a TO-247 device?

and

2. On the same datasheet as the sinks you referenced I found some that seem speced for TO-247's (the 657 series). Are these sinks -- http://www.mouser.com/ProductDetail/...M5P2w8Sx8qfhz0 -- too wide for your boards? Or, will they fit ok?

Thanks,
Steve
  Reply With Quote
Old 14th September 2009, 03:28 PM   #24
cviller is offline cviller  Denmark
diyAudio Member
 
cviller's Avatar
 
Join Date: Dec 2005
Location: Copenhagen
Blog Entries: 2
1. yes, its a tight fit, but it fits:
Gb: F5 Pcb

2. the 657 takes up too much space, and you still only have 17mm width for the to-247's
  Reply With Quote
Old 13th October 2009, 11:14 AM   #25
rtate is offline rtate  Canada
diyAudio Member
 
Join Date: Jan 2002
Location: Burlington, Ontario, Canada
Got the pcb's , Thanks Chris

Do I need to use mica insulators and thermal grease between the diodes
and heatsinks??
  Reply With Quote
Old 13th October 2009, 02:22 PM   #26
cviller is offline cviller  Denmark
diyAudio Member
 
cviller's Avatar
 
Join Date: Dec 2005
Location: Copenhagen
Blog Entries: 2
Quote:
Originally Posted by rtate View Post
Got the pcb's , Thanks Chris

Do I need to use mica insulators and thermal grease between the diodes
and heatsinks??
Thermal grease yes, but mica is optional. I use mica because then the heat sinks are not part of the circuit.
  Reply With Quote
Old 9th November 2009, 10:25 PM   #27
rtate is offline rtate  Canada
diyAudio Member
 
Join Date: Jan 2002
Location: Burlington, Ontario, Canada
Chris, I know this has been asked before but I need to be clear as I am making my Digikey order this week.
When these rectifiers are used for the F5 project do you recommend using snubber resistors?
Same question for the caps...

Thanks for all your efforts
  Reply With Quote
Old 9th November 2009, 10:30 PM   #28
cviller is offline cviller  Denmark
diyAudio Member
 
cviller's Avatar
 
Join Date: Dec 2005
Location: Copenhagen
Blog Entries: 2
The snubbers (caps and resistors) are inserted to filter out switching noise from the rectifiers, so this has nothing to do with what you are using the bridge for - with correctly matched snubbers (matched to diodes) you'll have measurable cleaner current.
The bridge will work without, but I believe it is better to have include them.
  Reply With Quote
Old 10th November 2009, 02:48 AM   #29
Renron is offline Renron  United States
diyAudio Member
 
Renron's Avatar
 
Join Date: Jan 2007
Location: Sacramento
rTate,

Go back and read from post #9 on this thread, I too asked all the questions you are asking now. BTW, use non- polarized caps in the snubbers. Or if you are stubborn like me, you can use high voltage rated polarized caps and verify their OK to use when derated for DC. Better to just use non-polarized caps.

Ron
__________________
"If it doesn't work properly, hope it catches on fire"- Nelson Pass @ BA3
"I fired up the prototype. Literally." The Prophet Pass.
  Reply With Quote
Old 10th November 2009, 12:40 PM   #30
rtate is offline rtate  Canada
diyAudio Member
 
Join Date: Jan 2002
Location: Burlington, Ontario, Canada
what would the lead spacing be for the capacitors??
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gb: Rectifier boards - alternative peranders Group Buys 8 29th April 2009 02:51 PM
two single secondaries, two rectifier boards lm4780 kit gbolly Chip Amps 5 23rd August 2008 07:59 AM
Need some help: one vs. two rectifier boards? ebenai Chip Amps 4 25th May 2007 11:49 AM
Anybody heard about Tarzian Silicon Rectifier for Tube Rectifier Replacement? zxx123 Tubes / Valves 4 21st February 2005 04:02 AM


New To Site? Need Help?

All times are GMT. The time now is 01:08 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2