User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Solid State Talk all about solid state amplification.

 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
 6th December 2004, 05:45 PM #1 mefistofelez diyAudio Member   Join Date: Apr 2002 Vbe Multiplier Help Please I have been trying to understand PMAs amplifier introduced here: http://www.diyaudio.com/forums/showt...543&highlight= I have a problem with a Vbe multiplier disclosed by Nelson Pass in his patent: US3,995,228. To achieve bias voltage Vb = 9 V, with 2*Vbe = 1.4 V, the equation to be solved is: (R1+R2+R3)/R2 = Vb/2*Vbe Setting R1=R3= 600 Ohm, R2 = 543 Ohm Looking at the schematics: web.telecom.cz/macura/pm_ab_er1.gif , the resistor R7 - corresponding to R2 - is 10 kOhm. Now, interestingly enough, simulation confirms the value 10kOhm. Any help would be appreciated. M
 6th December 2004, 05:55 PM #2 Nelson Pass   The one and only     Join Date: Mar 2001 By your own formula, you would expect the middle resistor R2 to be about 200 ohms, this of course reflecting a simple Vbe multiplier with two complementary devices and three resistors
 6th December 2004, 06:14 PM #3 mefistofelez diyAudio Member   Join Date: Apr 2002 Nelson wrote: "By your own formula, you would expect the middle resistor R2 to be about 200 ohms, this of course reflecting a simple Vbe multiplier with two complementary devices and three resistors." I have made a mistake, the value of 2*Vbe = 2.8 V ( I have a BE junction in series with a diode). However, it still does not explain the discrepancy. M

 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 Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         Dx Classic Amplifiers         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post hienrich Solid State 80 29th November 2010 10:25 PM fglabach Solid State 23 12th June 2009 04:56 AM Donk Solid State 7 22nd January 2008 01:55 AM PederBass Solid State 13 23rd March 2004 06:26 PM Kilowatt Solid State 19 7th September 2002 02:40 PM

 New To Site? Need Help?

All times are GMT. The time now is 10:24 AM.