My DIY UCD - Page 3

Kenshin · 7th May 2005, 03:54 PM

Automotive MOSFET...Something for motor drivers.

This recalls me the tales of certain tubes which are massive used as voltage regulators in 1940s, become "ultimate" audio devices now.

(Of course,540 is also something for voltage regulators.)

dv/dt...A MOTOROLA appnotes in 1990s said that reverse recovery faliure are NOT caused by dv/dt.

SSassen · 7th May 2005, 07:54 PM

Well, as for mosfets, I guess Bruno beat me to the punch by another thread he just started, but I was going to comment that PC motherboards (with which I work on a daily basis) feature mosfets that are optimized for this kind of thing, and are usually SMD. From what I gather from JohnW's designs he uses SMD mosfets almost exclusively.

Also the output coils etc. are readily available in very small packaging. Keep in mind that a modern Pentium 4 or Athlon-64 processor consumes about 100-watts at core voltages of about 1.5-volts. This is derived from the 3.3 and 5-volts lines of the main PSU by a dual or triple phase switching powersupply with usually four or six mosfets sinking to the pcb, thus having very little dissipation, that's quite a feat considering the peak currents are over 100A.

Just a thought really, but I'd be happy to glance over a few motherboards and note a few mosfet types if needed.

Best regards,

Sander Sassen
http://www.hardwareanalysis.com

Kenshin · 8th May 2005, 04:47 AM

The CPU power supply are Buck regulators--class D producing DC power-- running at 500KHz and meet diode reverse recovery problems. So the device are fully designed to fight against diode reverse recovery problems.

Nowadays the whole power regulator industry are advertising on "quick transient response" or "ultimate transient response" . Maybe some of them are suitable for audio use (or even faster)

At least TI have a gate driver with self-adapted dead time and NSC have a controller based on hysteresis scheme.

The only problem is the loudspeaker . How to get a loudspeaker with impedance < 1ohm?

DIY it with a big Nd-Fe-B magnet plus a thin, big aluminium film ?

The old,middle school experimentcome back to life : a wire between two magnets...which is once considered to have too low impedance...

Maybe we can design some motor in the middle-school way and drive it with MOSFET use a single big battery...The tales of Nautilius: A submarine powered by a single Na:Hg-water battery.

Kuzmenko · 30th September 2005, 06:02 PM

I don`t understand, is there a problem to put small capacitive/low charge shottky diode between drain and source of output mosfet? I.e. SR1100 (1A/100V) for IRF540* ?
There is no need for large current capability fot these diodes and they can be mount directly to mosfet`s legs

Workhorse · 6th February 2006, 04:32 PM

web.mit.edu/pricem/www/smps/report.pdf

classd4sure · 6th February 2006, 04:50 PM

Hi Kanwar,

That's very cool! Nice to see there's a reference too. Thanks.

Thanks for posting it.

Regards,
Chris

Workhorse · 6th February 2006, 04:55 PM

kartino · 7th February 2006, 01:05 AM

Hi,

Seem that Q11, Q12, schematic at page 26th, have wrong connection for pin E and pin C?

classd4sure · 7th February 2006, 02:27 AM

Quote:

Originally posted by kartino
Hi,

Seem that Q11, Q12, schematic at page 26th, have wrong connection for pin E and pin C?

You're right

There's also other errors.

Copying and pasting is getting harder for students these days it seems.

Well, at least the thread was referenced.

Best Regards,
Chris

cotdt · 7th February 2006, 02:29 AM

i likes! how bout a Tripath design for all of us?

6th February 2006, 04:32 PM	#25
Workhorse diyAudio Member Join Date: Dec 2004 Location: ḺΛβ	web.mit.edu/pricem/www/smps/report.pdf __________________

6th February 2006, 04:55 PM	#27
Workhorse diyAudio Member Join Date: Dec 2004 Location: ḺΛβ	__________________

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7th May 2005, 03:54 PM	#21
Kenshin diyAudio Member Join Date: Jan 2005 Location: China	Automotive MOSFET...Something for motor drivers. This recalls me the tales of certain tubes which are massive used as voltage regulators in 1940s, become "ultimate" audio devices now. (Of course,540 is also something for voltage regulators.) dv/dt...A MOTOROLA appnotes in 1990s said that reverse recovery faliure are NOT caused by dv/dt.

7th May 2005, 07:54 PM	#22
SSassen diyAudio Member Join Date: Mar 2005 Location: Purmerend	Well, as for mosfets, I guess Bruno beat me to the punch by another thread he just started, but I was going to comment that PC motherboards (with which I work on a daily basis) feature mosfets that are optimized for this kind of thing, and are usually SMD. From what I gather from JohnW's designs he uses SMD mosfets almost exclusively. Also the output coils etc. are readily available in very small packaging. Keep in mind that a modern Pentium 4 or Athlon-64 processor consumes about 100-watts at core voltages of about 1.5-volts. This is derived from the 3.3 and 5-volts lines of the main PSU by a dual or triple phase switching powersupply with usually four or six mosfets sinking to the pcb, thus having very little dissipation, that's quite a feat considering the peak currents are over 100A. Just a thought really, but I'd be happy to glance over a few motherboards and note a few mosfet types if needed. Best regards, Sander Sassen http://www.hardwareanalysis.com

8th May 2005, 04:47 AM	#23
Kenshin diyAudio Member Join Date: Jan 2005 Location: China	The CPU power supply are Buck regulators--class D producing DC power-- running at 500KHz and meet diode reverse recovery problems. So the device are fully designed to fight against diode reverse recovery problems. Nowadays the whole power regulator industry are advertising on "quick transient response" or "ultimate transient response" . Maybe some of them are suitable for audio use (or even faster) At least TI have a gate driver with self-adapted dead time and NSC have a controller based on hysteresis scheme. The only problem is the loudspeaker . How to get a loudspeaker with impedance < 1ohm? DIY it with a big Nd-Fe-B magnet plus a thin, big aluminium film ? The old,middle school experimentcome back to life : a wire between two magnets...which is once considered to have too low impedance... Maybe we can design some motor in the middle-school way and drive it with MOSFET use a single big battery...The tales of Nautilius: A submarine powered by a single Na:Hg-water battery.

30th September 2005, 06:02 PM	#24
Kuzmenko diyAudio Member Join Date: Nov 2004 Location: Zaporozhye	I don`t understand, is there a problem to put small capacitive/low charge shottky diode between drain and source of output mosfet? I.e. SR1100 (1A/100V) for IRF540* ? There is no need for large current capability fot these diodes and they can be mount directly to mosfet`s legs

6th February 2006, 04:50 PM	#26
classd4sure Account Disabled Join Date: Feb 2004	Hi Kanwar, That's very cool! Nice to see there's a reference too. Thanks. Thanks for posting it. Regards, Chris

7th February 2006, 01:05 AM	#28
kartino diyAudio Member Join Date: Feb 2005 Location: Gunungkidul Indonesia	Hi, Seem that Q11, Q12, schematic at page 26th, have wrong connection for pin E and pin C?

7th February 2006, 02:29 AM	#30
cotdt diyAudio Member Join Date: Oct 2005	i likes! how bout a Tripath design for all of us?

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