dumb power supply question

nobody special · 12th January 2003, 12:11 AM

When using two seperate power transformers for + and - rails with a pi filter and inrush suppressors, where is the appropriate place to put the inrush suppressors and choke for the negative bridge?
Do you tie the + of the negative bridge to the - of the + bridge right at the rectifiers and put the choke and suppressors on the - line, or do you put the choke inline with the + side, and then tie your common point at the last filter cap?
-NS

AudioFreak · 12th January 2003, 04:48 AM

Tie the -ve out of the +ve bridge to the +ve out of the -ve bridge. That is your ground line. You can put the inrush suppressor on the active mains wire directly before the transformer if it is suitably rated. For the Pi-filter, it goes caps-choke-caps, so for the +ve supply make sure you place the caps with their +ve lead connected to the +ve rail and their -ve lead to ground. Then the choke goes after the caps in series with the +ve rail, then the rest of the caps same as the 1st lot only placed after the cap. For the -ve rail, the procedure is the same except that you must place the caps with their +ve lead connected to ground and their -ve lead connected to the -ve rail.

Hope this helps answer some of your questions.

nobody special · 12th January 2003, 10:12 PM

Thanks for the reply...
I don't think I was clear in describing what I am trying to do.
The inrush suppressors that I will be using are going to go after the rectifier(s). They are NTC type CL thermistors- rated at 16 amps continuous, with about .05 ohms of resistance with the 7 amps constant current of my Aleph X going through them, but they will be .5Ohms at turn on. I decided to use an RCRCRC type filter, with thermistors between each bank of caps, instead of a choke. I guess my question would be where to put the thermistors for the (-) rectifier/ rail. Is it alright to put them in series with the (-) side of the caps and tie the rails together to get a ground right at the rectifiers, or should they always be on the + side of the capacitors?

12th January 2003, 12:11 AM	#1
nobody special diyAudio Member Join Date: Oct 2002 Location: USA	dumb power supply question When using two seperate power transformers for + and - rails with a pi filter and inrush suppressors, where is the appropriate place to put the inrush suppressors and choke for the negative bridge? Do you tie the + of the negative bridge to the - of the + bridge right at the rectifiers and put the choke and suppressors on the - line, or do you put the choke inline with the + side, and then tie your common point at the last filter cap? -NS

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
Some dumb Questions on Heater CCS supply	jkeny	Tubes / Valves	2	19th September 2008 08:05 PM
Dumb question, but...	johnm	Tubes / Valves	3	13th June 2008 10:14 PM
Dumb question.	G	Tubes / Valves	2	16th January 2008 08:16 PM
maybe this is too dumb a question...	dannyspencer	Solid State	6	18th April 2004 04:57 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


	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

12th January 2003, 04:48 AM	#2
AudioFreak Warp Engineer On Holiday Join Date: Oct 2001 Location: Queensland, Australia	Tie the -ve out of the +ve bridge to the +ve out of the -ve bridge. That is your ground line. You can put the inrush suppressor on the active mains wire directly before the transformer if it is suitably rated. For the Pi-filter, it goes caps-choke-caps, so for the +ve supply make sure you place the caps with their +ve lead connected to the +ve rail and their -ve lead to ground. Then the choke goes after the caps in series with the +ve rail, then the rest of the caps same as the 1st lot only placed after the cap. For the -ve rail, the procedure is the same except that you must place the caps with their +ve lead connected to ground and their -ve lead connected to the -ve rail. Hope this helps answer some of your questions.

12th January 2003, 10:12 PM	#3
nobody special diyAudio Member Join Date: Oct 2002 Location: USA	Thanks for the reply... I don't think I was clear in describing what I am trying to do. The inrush suppressors that I will be using are going to go after the rectifier(s). They are NTC type CL thermistors- rated at 16 amps continuous, with about .05 ohms of resistance with the 7 amps constant current of my Aleph X going through them, but they will be .5Ohms at turn on. I decided to use an RCRCRC type filter, with thermistors between each bank of caps, instead of a choke. I guess my question would be where to put the thermistors for the (-) rectifier/ rail. Is it alright to put them in series with the (-) side of the caps and tie the rails together to get a ground right at the rectifiers, or should they always be on the + side of the capacitors?

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