I'm interested in trying this out, too, but haven't the
foggiest where to purchase a unit that isn't +/-5
and +12 output. (Most of my searches have
turned up supplies intended for PC motherboards.)
Any suggestions on what terns to search for to get
a unit that will provide +/-24 or +/- 48 volt ouputs
at several amps?
Erik
foggiest where to purchase a unit that isn't +/-5
and +12 output. (Most of my searches have
turned up supplies intended for PC motherboards.)
Any suggestions on what terns to search for to get
a unit that will provide +/-24 or +/- 48 volt ouputs
at several amps?
Erik
It was done in the Linn Klimax Twin.
Anybody heard of this amplifier or even tried?
I always wondered why this cost 10000€.
It´s SMPS supply and 6*TDA7294 for quite a bit of stereo power.
Anybody got a schematic for that one?. (just for interest)
It´s an interesting topic to "skip" the big transformer you usually need for audio applications but building a good and reliable SMPS supply will probably turn out to be more complicate than the amp itself !?
Anybody heard of this amplifier or even tried?
I always wondered why this cost 10000€.
It´s SMPS supply and 6*TDA7294 for quite a bit of stereo power.
Anybody got a schematic for that one?. (just for interest)
It´s an interesting topic to "skip" the big transformer you usually need for audio applications but building a good and reliable SMPS supply will probably turn out to be more complicate than the amp itself !?
thanks for the replies
well, yhea, thats a major point, in a small box about as big as a computer psu, you can have a like 700 watts power supply, and not evryone wants to buy an very expensive psu, or to wind one...
ive started a half bridge smps to power my computer system because i cant find a 17 amps +\- 35v psu, and even if i did find one, can you imagine the size of that :|
well, yhea, thats a major point, in a small box about as big as a computer psu, you can have a like 700 watts power supply, and not evryone wants to buy an very expensive psu, or to wind one...
ive started a half bridge smps to power my computer system because i cant find a 17 amps +\- 35v psu, and even if i did find one, can you imagine the size of that :|
Interesting subject indeed,
SMPS aren't easy to design for custom applications. The basic ideas however are simple.
But before you plunge yourself in the datasheets and wild dreams: Besides it being smaller and lighter, why would you want a SMPS? Think about the (expensive) HF transformer you would have to obtain, the HF distosion you introduce in you Power Rails, the heat they produce, and often horrendous stability they sometimes provide. (Computer PSU's are known for it).
Would they really provide that much advantages over that?
Bouke
SMPS aren't easy to design for custom applications. The basic ideas however are simple.
But before you plunge yourself in the datasheets and wild dreams: Besides it being smaller and lighter, why would you want a SMPS? Think about the (expensive) HF transformer you would have to obtain, the HF distosion you introduce in you Power Rails, the heat they produce, and often horrendous stability they sometimes provide. (Computer PSU's are known for it).
Would they really provide that much advantages over that?
Bouke
yhea, thats what ive been asking myself for months.
But, can u simply imagine how big is a 17-20 amps psu at like from 35-50v +\- rails
yes, thats big....
and very heavy
for my pc system project, i need a 35 to 50v +/- at 15.5 amps psu
and thats not counting the amps loss... and evrything
so that makes a 17-20 amps psu at 35-50v, i just cant integrate such a psu in a woofer enclosure, unless its a smps,
any other suggestions?
But, can u simply imagine how big is a 17-20 amps psu at like from 35-50v +\- rails
yes, thats big....
and very heavy
for my pc system project, i need a 35 to 50v +/- at 15.5 amps psu
and thats not counting the amps loss... and evrything
so that makes a 17-20 amps psu at 35-50v, i just cant integrate such a psu in a woofer enclosure, unless its a smps,
any other suggestions?
Banned
Joined 2002
smps are loud and verry noisy and if you have a nice working aleph 1 2 4 5 6 what ever there numbers are and go upt to say you did get it working IT WOULD suck if the psu blew up because when they blow they blow every thing along the line. i work in a computer shop and see psus blowing all the time.. and i deal with lots of them issues. the only good amps that i know that use smps's are carver and qsc but you have to pay lots of money to have one. and if you have ever sseen a carver amp after it has blown up the smps's ones there garbage because they basicaly blow them selves up all the outputs and ect components. it would cost you to much to fix it PROPERLY.
jason
jason
Banned
Joined 2002
haha, yhea thats scary, but think about it, if they were so bad, and dangerous, no pc would be using em..
anyway, i got no choice but to design a smps... im in electronical engineering in college, im sure theres some teachers and researchers there who could help me.
anyone has ever made this? a complete design? ive been making one for a car system..
http://www.hills2.u-net.com/electron/smps.htm#halfbrdg
theres alot of info on the subject, and btw, most of the smps dont need a fan, therefore they are not loud, a good smps with good parts, fast mosfets low loss diodes, u should be ok with some heatsinks, anyway, thats what I think, and i could be wrong.
anyway, i got no choice but to design a smps... im in electronical engineering in college, im sure theres some teachers and researchers there who could help me.
anyone has ever made this? a complete design? ive been making one for a car system..
http://www.hills2.u-net.com/electron/smps.htm#halfbrdg
theres alot of info on the subject, and btw, most of the smps dont need a fan, therefore they are not loud, a good smps with good parts, fast mosfets low loss diodes, u should be ok with some heatsinks, anyway, thats what I think, and i could be wrong.
Banned
Joined 2002
Ilianh said:
Yes they would actually... :/ And not because they are so safe, but because they are so cheap. And Computer PSU's are so cheap because they are produced by the thousands a time.
Ok they will work, but they still won't be suitable for amplifier design i think. The two things that make SMPS so nasty are 1: they are noisy. Not just a fan, the semiconductors, the transformer, and almost all components in the power path are under huge stress (High Power, High Current). If components are under stress, they make sounds. Besides that, the power rails they produce are far from clean and stable. 2: And this is actually more of a problem for the power companies, but SMPS produce a really nasty, low power factor. This is mainly due to the caps behind the primary voltage rectifier. Because they only charge when the voltage in the mains rises above the voltage in the caps, they produce a pulse-shaped load for the mains. This soils the net, and puts extra stress on the generators in the power plant.
"Normal" PSU's don't have this problem because of the transformer, that shields the net for these peak currents.
But I'll be willing to help you get along anyway. I'm a student electrical engineering too, and I'm about to specialise in high power electronics and energy distribution. SMPS are something I need to know a lot about
Bouke
kiwi_abroad said:
D'OH! I should have thought of that. It's only been a few years
since I was developing test software for cellular base stations...
How quickly the mind turns to other things.
I'll look up the company that built our HUGE 27volt supplies to see
if they make something smaller and more affordable.
Erik
eLarson, i dont think the last reply u did was neccesary or related to the topic in any ways :|, or am i wrong
anyhow,
Bakmeel, thx alot for the info,
ok, i understand that a "normal" psu is way better, but here the problem is bigger
im making a 5.1 system for my pc, speakers are 8 ohm 5" 20 w drivers and with 2" tweeters
the subwoofer is a dual 8" 75 watt 4 oh per driver
that makes like 1.5 amps per satelite, and 8 amps for the 2 woofers.
thats a total of 16-17 amps considering losses and all
yhea i know this is an absolute maximum to the system and i dont think i`ll ever hit that usage,
but i just cant use a transformer thats gonna be like 16-17 amps at 40-50v +/-
I think pc sound systems like klipsch promedia 5.1 use smps in their systems, and car amps use smps too, im sure theres a way to work out something thats gonna be reliable, cost effective and size effective.
at first i wanted to make the amp using 5 aleph 3 and some woofer amps
then i realised that i didnt need something as high quality as this in a pc setup. So i`ll go with some lm3886 maybe..
any ideas how the smps is gonna work on them?
and how some pc systems like the promedia 5.1 are reliable with smps? (if im not wrong about them using smps)
anyhow,
Bakmeel, thx alot for the info,
ok, i understand that a "normal" psu is way better, but here the problem is bigger
im making a 5.1 system for my pc, speakers are 8 ohm 5" 20 w drivers and with 2" tweeters
the subwoofer is a dual 8" 75 watt 4 oh per driver
that makes like 1.5 amps per satelite, and 8 amps for the 2 woofers.
thats a total of 16-17 amps considering losses and all
yhea i know this is an absolute maximum to the system and i dont think i`ll ever hit that usage,
but i just cant use a transformer thats gonna be like 16-17 amps at 40-50v +/-
I think pc sound systems like klipsch promedia 5.1 use smps in their systems, and car amps use smps too, im sure theres a way to work out something thats gonna be reliable, cost effective and size effective.
at first i wanted to make the amp using 5 aleph 3 and some woofer amps
then i realised that i didnt need something as high quality as this in a pc setup. So i`ll go with some lm3886 maybe..
any ideas how the smps is gonna work on them?
and how some pc systems like the promedia 5.1 are reliable with smps? (if im not wrong about them using smps)
Ilianh,
Sorry for the delay...I've got an exam week next week, so i'm kinda busy prepping all five exams...
Perhaps you should take a look at this one: Take a look at the Datasheet and the application note from this Switchmode Controller:
Datasheet
Application note
That's just for starters. You will need to look for Switchmode Controller IC's. Select one that is capable of driving enough Mosfets to suit your power needs. Also, make sure it can handle high power input (110V), and high power output (40V). Then you can determine the frequency it will be woring on. Make sure it is working WAY above the frequency spectrum, but not too high, because HF power is nasty to harness (EMC and stuff like that).
Then pick Mosfets, input and output caps, and then the rest of the components! easy!
Try to get an efficiency as high as possible. You dont want to dissipate 50W in your PSU already!
Good luck
Bouke
Sorry for the delay...I've got an exam week next week, so i'm kinda busy prepping all five exams...
Perhaps you should take a look at this one: Take a look at the Datasheet and the application note from this Switchmode Controller:
Datasheet
Application note
That's just for starters. You will need to look for Switchmode Controller IC's. Select one that is capable of driving enough Mosfets to suit your power needs. Also, make sure it can handle high power input (110V), and high power output (40V). Then you can determine the frequency it will be woring on. Make sure it is working WAY above the frequency spectrum, but not too high, because HF power is nasty to harness (EMC and stuff like that).
Then pick Mosfets, input and output caps, and then the rest of the components! easy!
Try to get an efficiency as high as possible. You dont want to dissipate 50W in your PSU already!
Good luck
Bouke
As much as I hate fans, this is what i've done to my SMPS in my computer. So far so good after 3 days uptime 
http://www.geocities.com/super_bq/Misc/IMG_1019.jpg
http://www.geocities.com/super_bq/Misc/IMG_1019.jpg
An externally hosted image should be here but it was not working when we last tested it.
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