Current rating and tube current draw

cbutterworth · 12th October 2006, 11:55 PM

I started a new thread. It follows on from the Aikido PSU thread.

If I am going to test the Aikido using a number of different tubes, I can use Broskie's chart to look up current draw for the tubes. I add up the lk for the input and for the output.

Suppose I get 90mA total current draw. Does that mean that I need a power transformer that is rated 90mA or higher?? Or would a power transformer rated at 50mA work??

Charlie

ray_moth · 13th October 2006, 05:42 AM

It is conventional wisdom that a PSU with capacitor-input filter can provide about 60% of the rated maximum current draw of the power tranny's sedcondary. For 90mA, you need a power tranny rated at 100*90/60 mA = 150mA.

If you have a choke-input filter, you could probably get away with a 90mA rated tranny but you would need a higher voltage from it, about 110% of the required B+.

12th October 2006, 11:55 PM	#1
cbutterworth diyAudio Member Join Date: Oct 2006	Current rating and tube current draw I started a new thread. It follows on from the Aikido PSU thread. If I am going to test the Aikido using a number of different tubes, I can use Broskie's chart to look up current draw for the tubes. I add up the lk for the input and for the output. Suppose I get 90mA total current draw. Does that mean that I need a power transformer that is rated 90mA or higher?? Or would a power transformer rated at 50mA work?? Charlie

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
Tube Preamp L&R Channel different current draw	tube cadet	Tubes / Valves	0	21st January 2009 01:37 AM
power transformer rating and tube current - SimpleSE	cbutterworth	Tubes / Valves	17	12th June 2008 11:54 PM
current draw of a chipamp	jarthel	Chip Amps	2	13th July 2007 12:45 PM
current draw on a gainclone?	cowanrg	Chip Amps	9	9th August 2003 07:58 AM
Opamp current draw	5th element	Solid State	2	21st July 2003 01:11 AM

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

13th October 2006, 05:42 AM	#2
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	It is conventional wisdom that a PSU with capacitor-input filter can provide about 60% of the rated maximum current draw of the power tranny's sedcondary. For 90mA, you need a power tranny rated at 100*90/60 mA = 150mA. If you have a choke-input filter, you could probably get away with a 90mA rated tranny but you would need a higher voltage from it, about 110% of the required B+.

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