Quick question about CT and FWB

athos56 · 2nd May 2009, 03:09 AM

I have a 40VCT (20 - 0 - 20) transformer that I'm using to make a 40v PSU with a FWB rectifier, what I need to know is, what do I do with the CT? Whats the difference between grounding it and leaving it unconnected? I tried to search but the search engine wasn't very helpful.

HollowState · 2nd May 2009, 03:29 AM

Do not connect the CT to anything. Protect it form touching anything by folding it and either taping it up or slide a piece of heat shrink tubing over it. If you used the CT, you could get ± 20V.

Tom Bavis · 2nd May 2009, 03:30 AM

DO NOT ground it if you will have either end of the bridge connected to ground.

athos56 · 2nd May 2009, 04:04 AM

Quote:

Originally posted by HollowState
Do not connect the CT to anything. Protect it form touching anything by folding it and either taping it up or slide a piece of heat shrink tubing over it. If you used the CT, you could get ± 20V.

This is what I did, I just had a moment of confusion. New baby=no sleep=maybe I should check all my work, twice.

Thanks for answering the simple question of the night.

Richard Ellis · 2nd May 2009, 04:33 AM

Are you a newbie at PS design?? As in, you won't get an exact 40VDC from this transformer.
Appx 56VDC for straight Cap.
36 VDC for choke input design OR
40 VDC straight cap plus regulation

My apologies for noting this if your already aware.
_________________________________________________R ick....

athos56 · 2nd May 2009, 05:27 AM

This will be my 6th one. Although it is the first solid state FWB PSU I've made, hence the moment of confusion. I have a few RC filters to bring the voltage down and I'm not concerned with 10% (+/- 4v) error, which I've found isn't noticeable, at least to me. I got it sim'd out with PSUD II as well. Thanks for checking though

It is a psudo-dual mono supply with 2 small chokes in some LC filters at the split, followed by a few RC filters and a gyrator at the end (as an experiment) to kill what ever ripple is left.

2nd May 2009, 03:09 AM	#1
athos56 diyAudio Member Join Date: May 2006 Location: Yakima, Washington	Quick question about CT and FWB I have a 40VCT (20 - 0 - 20) transformer that I'm using to make a 40v PSU with a FWB rectifier, what I need to know is, what do I do with the CT? Whats the difference between grounding it and leaving it unconnected? I tried to search but the search engine wasn't very helpful.

2nd May 2009, 03:29 AM	#2
HollowState diyAudio Member Join Date: Aug 2006 Location: Taxland, New Jersey	Do not connect the CT to anything. Protect it form touching anything by folding it and either taping it up or slide a piece of heat shrink tubing over it. If you used the CT, you could get ± 20V. __________________ "The human race is just a chemical scum on a moderate-sized planet orbiting round a very average star in the outer suburb of one among a hundred billion galaxies." ~Stephen Hawking

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Quick question on the PP-C1 amp	athos56	Tubes / Valves	13	20th October 2007 07:37 PM
Quick quick question !	guitvinny	Pass Labs	6	7th February 2007 05:20 PM
Quick PCB question	Piper	Chip Amps	2	7th March 2005 11:59 AM
VERY quick question...	Wyloch	Multi-Way	2	3rd March 2005 05:34 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

2nd May 2009, 03:30 AM	#3
Tom Bavis diyAudio Member Join Date: Jun 2002 Location: Macedon NY	DO NOT ground it if you will have either end of the bridge connected to ground.

2nd May 2009, 04:33 AM	#5
Richard Ellis diyAudio Member Join Date: Sep 2006 Location: Mar del Plata, a BIG seasonal getaway city, can see the Ocean from our residence.	Are you a newbie at PS design?? As in, you won't get an exact 40VDC from this transformer. Appx 56VDC for straight Cap. 36 VDC for choke input design OR 40 VDC straight cap plus regulation My apologies for noting this if your already aware. _________________________________________________R ick....

2nd May 2009, 05:27 AM	#6
athos56 diyAudio Member Join Date: May 2006 Location: Yakima, Washington	This will be my 6th one. Although it is the first solid state FWB PSU I've made, hence the moment of confusion. I have a few RC filters to bring the voltage down and I'm not concerned with 10% (+/- 4v) error, which I've found isn't noticeable, at least to me. I got it sim'd out with PSUD II as well. Thanks for checking though It is a psudo-dual mono supply with 2 small chokes in some LC filters at the split, followed by a few RC filters and a gyrator at the end (as an experiment) to kill what ever ripple is left.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)