SMPS & tube pre-amp development board. - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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
Reply
 
Thread Tools Search this Thread
Old 2nd April 2006, 06:24 PM   #1
ianl is offline ianl  Netherlands
diyAudio Member
 
Join Date: Feb 2006
Location: Netherlands
Default SMPS & tube pre-amp development board.

I posted pictures, circuit, and schematic for my first attempt at a SMPS/tube preamp at instructables:


LINK

http://www.instructables.com/ex/i/D4...5001143E7E506/

Thanks to everyone who answered my questions about switching the tube heater.

Cheers,

Ian
Attached Images
File Type: jpg mreztubeside.jpg (67.2 KB, 300 views)
  Reply With Quote
Old 10th April 2006, 04:42 PM   #2
nickds1 is offline nickds1  England
diyAudio Member
 
nickds1's Avatar
 
Join Date: Aug 2005
I'm slightly puzzled as to why you use a PIC & FET driver to make an SMPS when there are several appropriate single chip specialist SMPS devices around that give you all sorts of stuff, such as very high performance (I get approx 88% efficiency), current limiting, HV shutoff etc. for very very little cost. The EMI/RFI is also easy to control - I use a variety of HP & Tek test kit to check my amps' performance, and removing SMPS artifacts (however you make the SMPS) is non-trivial, but can be done by using high switching frequencies, and careful control of artifacts on the supply rails, using shielded inductors and management of the grond plane.

For small tube/valve projects, my preferred chip is a MAX1771:

MAX1771 Nixie/Valve PSU.

The above link was originally done as a Nixie PSU a few years back but is widely used by valve/tube radio enthusiasts as a battery eliminator - I didn't use the Maxim app note as it didn't actually save any chips or components, as to drive the FET properly you need a specialist driver device - a PIC or an AVR doesn't have I/O ports that are "stiff" enough to get decent efficiency directly driving a FET, and there are capacitively induced currents in the FET gate that can & will damage the MCU's I/O ports. This is why LT,Maxim et al make specialist SMPS chips...

Its easy to make an SMPS, but getting one to do the best possible job is tricky.
__________________
Nicko
"The whole plan hinged upon the natural curiosity of potatoes" - S. Lem
  Reply With Quote
Old 10th April 2006, 06:05 PM   #3
ianl is offline ianl  Netherlands
diyAudio Member
 
Join Date: Feb 2006
Location: Netherlands
I use the TC4427a fet driver from microchip.

Also: switching at higher frequencies is not always so straight forward. The coil charge and discharge time can be calculated. Frequencies beyond these limits don't use the coil to its fullest. Slower frequencies burn energy in the coil or fet. There is a "best frequency" for a given coil. The pic calculates this based on coil size and supply voltage. I have worked with the 1771 in the past. I just really lke having software control and not being locked into a certain vendor.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Car audio LM3886 + SMPS on single sided board rwaudio Chip Amps 42 30th January 2013 10:01 PM
Smps In Development albert_emule Power Supplies 3 11th April 2009 10:29 PM
SMPS for tube amp? kubeek Tubes / Valves 15 20th May 2006 12:24 PM
DSP development board suggestions starn02 Digital Source 0 14th April 2006 07:06 AM
Development board Atmel ATmega Freddie Everything Else 1 16th August 2003 03:27 PM


New To Site? Need Help?

All times are GMT. The time now is 08:41 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2