SSLV1.1 builds & fairy tales - Page 62 - diyAudio
 SSLV1.1 builds & fairy tales
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 20th October 2011, 04:31 PM #611 diyAudio Member   Join Date: Sep 2008 So What current is your transformer providing for each secondary? What value have you for R101? Four LEDs green, correct? What is the voltage drop across each green LED? What value for C105? Chris Last edited by Backbones; 20th October 2011 at 04:33 PM.
diyAudio Member

Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
 Originally Posted by Backbones So What current is your transformer providing for each secondary? 30VA What value have you for R101? 3R3 Four LEDs green, correct? YES What is the voltage drop across each green LED? 1.8-1.9V What value for C105? 10.000Uf Chris

 20th October 2011, 05:01 PM #613 diyAudio Member   Join Date: Sep 2008 Transformer current sufficient. 4 times 1.9V = 7.6V Say current draw of 700mA = Vgs of about 5.5V. 7.6-5.5=2.1V I=V/R. I=2.1/3.3. I=640mA. Not enough current for 700mA. R101 needs to be 3ohm or lower (2.1/0.7). I don't know up to what current the BiB is designed to go. chris
diyAudio Member

Join Date: Feb 2010
Quote:
 Originally Posted by Salas Use 3 1.9V leds and 1.2R 2W setting resistor (R101 etc.) for 0.5A available if you can't find 1.3R.
Hmm, Salas just to confirm, 1.9V = RED LEDs, yes? Because i saw other people who used the regs in the same application and they used the green LEDs in Dx02,x03,x04 instead. Is it because their current used is different?

diyAudio Member

Join Date: Jul 2004
Location: Scottish Borders
Quote:
 Originally Posted by coolhead Voltage across R301: 6.3Vac trans = 1.31V 9Vac trans = 1.36V R301 is 10ohm The output is the same 3.3V, the different will be CCS current of 50mA.
and now turn the mains supply voltage down to suppliers specified minimum. Measure again.

The fact that you have already lost 50mV tells me you are getting close to dropping out.
__________________
regards Andrew T.
Sent from my desktop computer using a keyboard

diyAudio Member

Join Date: Sep 2009
Location: Catalonia - Europe
Measured voltage accross R1 2.37 V : 3R3 = 718mA

BTW enough for B3...
Attached Images
 DSC00051.jpg (745.0 KB, 341 views) DSC00052.jpg (500.2 KB, 312 views)

Last edited by merlin el mago; 20th October 2011 at 05:12 PM.

diyAudio Member

Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
 Originally Posted by cersepn Hmm, Salas just to confirm, 1.9V = RED LEDs, yes? Because i saw other people who used the regs in the same application and they used the green LEDs in Dx02,x03,x04 instead. Is it because their current used is different?
Different voltage.

diyAudio Member

Join Date: Sep 2008
Quote:
 Originally Posted by merlin el mago Measured voltage accross R1 2.37 V : 3R3 = 718mA
OK. After calculation errors it is about the right current levels. The drop across the LEDs depends on their current I believe to some degree.
If you are supplying the right current at the reg level one has to ask if the load is drawing more than this?
Chris

diyAudio Member

Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
 Originally Posted by Backbones OK. After calculation errors it is about the right current levels. The drop across the LEDs depends on their current I believe to some degree. If you are supplying the right current at the reg level one has to ask if the load is drawing more than this? Chris
Extracted from leonvb BIII manual in the TP site:

"The standard board requires an input voltage of 5.25V and it draws approximately 440mA when one is using the recommended set of Trident shunt regulators"

diyAudio Member

Join Date: Sep 2008
Quote:
 Originally Posted by Salas Looks 5ish to me, better calculate based on Vgs=5V. Also your LEDS maybe ~1.9V at the small current they will run, their spec voltage drop Vf is given at 20mA nominal usually.
From an earlier post.
Chris

 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 OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Tea-Bag Group Buys 1638 22nd May 2017 10:11 PM CaNNA3IS Swap Meet 1 24th November 2013 09:43 AM korben69 Swap Meet 6 2nd July 2013 09:32 AM CSS/XBL CSS 0 11th April 2013 05:34 PM amp builder jb Tubes / Valves 29 15th July 2005 08:23 PM

 New To Site? Need Help?

All times are GMT. The time now is 04:30 PM.