hi all..
i have a little problem.. ive been asked to make a 1000W amp for a car(!!😱 !!) to power 6 subs.. (dont ask me why).. i want to use nat. semi's. LM3886 amp ic for this..
i have the following problems:
1) the power supply requirements: could someone point me onto a nice smps design?? (from 12V to 35 V; and from 5A to 35A)
2) any schematic on how to bridge or parrallel the ic??
any help is welcome..
thanx in advance..
madhu.
i have a little problem.. ive been asked to make a 1000W amp for a car(!!😱 !!) to power 6 subs.. (dont ask me why).. i want to use nat. semi's. LM3886 amp ic for this..
i have the following problems:
1) the power supply requirements: could someone point me onto a nice smps design?? (from 12V to 35 V; and from 5A to 35A)
2) any schematic on how to bridge or parrallel the ic??
any help is welcome..
thanx in advance..
madhu.
For a SMPS design go to:
http://www.sound.au.com
You could check the datasheet and application note for information on how to bridge LM3886.
http://www.sound.au.com
You could check the datasheet and application note for information on how to bridge LM3886.
Re: Re: 100 W amp?!?!
Yep.
Getting 1000W out of LM3886s will be an interesting task.
First, run them at 40-0-40... its very close to absolute max ratings, but they can take it. Ive been running 16 LM3886s at this level for the past year or so.
A BIG issue will be heatsinking, expect lots of experimenting, and buying different heatsinks/fans to try and get them cooled well enough to stop clipping.
See if you can setup your speakers as a 2ohm load... will be easier to get the power output your after at this level.
JordanG said:
Yep.
Getting 1000W out of LM3886s will be an interesting task.
First, run them at 40-0-40... its very close to absolute max ratings, but they can take it. Ive been running 16 LM3886s at this level for the past year or so.
A BIG issue will be heatsinking, expect lots of experimenting, and buying different heatsinks/fans to try and get them cooled well enough to stop clipping.
See if you can setup your speakers as a 2ohm load... will be easier to get the power output your after at this level.
Divide and conquer!
If you have 6 subs then the smart thing to do IMHO would be to make 6 amplifiers each of 166.6666 watts, which would be a *lot* easier than one whopping big one, and drive each sub separately. They could all run off the same power supply of course. If an LM3886 will make 68 watts then two bridged will make 136 watts. You're almost there!
madhu said:
If you have 6 subs then the smart thing to do IMHO would be to make 6 amplifiers each of 166.6666 watts, which would be a *lot* easier than one whopping big one, and drive each sub separately. They could all run off the same power supply of course. If an LM3886 will make 68 watts then two bridged will make 136 watts. You're almost there!
Jean said:
Yeh it would, but not as fun 😉
Not quite, bridged LM3886s cant handle 4ohm loads.
To drive a 4ohm load you still need to bridge/parallel.
I don't think that is a good idea to use a large number of integrated amplifiers.
In my opinion the best way to make this huge power amp is to make two pieces very low Z amps and use in bridge mode.
Example: For 500W / 0,5 - 0,8 ohm you will need +/- 40 to 45V cc at 800VA minimum.
In my opinion the best way to make this huge power amp is to make two pieces very low Z amps and use in bridge mode.
Example: For 500W / 0,5 - 0,8 ohm you will need +/- 40 to 45V cc at 800VA minimum.
100W Bdg Amp
Try TDA7294 in Bdg mode. It should diliver much in excess of 140W/16E with proper heatsink and power supply. It has mute and st-by to eliminate pops.
Should be good easy and relatively cheap.
bimbla.
Try TDA7294 in Bdg mode. It should diliver much in excess of 140W/16E with proper heatsink and power supply. It has mute and st-by to eliminate pops.
Should be good easy and relatively cheap.
bimbla.
thanx all for the responses..
even i thought of the same thing..
also for the power supply, im thinking of getting a 1kva ups, ripping the battery out, connecting a 12V, 25A/H battery, inverting the dc voltage into AC, then rectifying it to obtain the required current and voltage...
does anyone think of this idea as feasible? please let me know...
best rgds,
madhu.
even i thought of the same thing..
also for the power supply, im thinking of getting a 1kva ups, ripping the battery out, connecting a 12V, 25A/H battery, inverting the dc voltage into AC, then rectifying it to obtain the required current and voltage...
does anyone think of this idea as feasible? please let me know...
best rgds,
madhu.
Alot of people have replaced the batteries in there UP's and 9/10 it works.
As a cheaper alternative Oatley Electronics offers an inverter kit which you can either buy with/out a transformer to 240v. If you don't mind winding your own transformer its a very cheap alternative to a modded ups. See Rod elliots SMPS design for transformer ideas, its basicly the same circuit/output.
quote
also for the power supply, im thinking of getting a 1kva ups, ripping the battery out, connecting a 12V, 25A/H battery, inverting the dc voltage into AC, then rectifying it to obtain the required current and voltage...
most of the apc (brand name) and a lot of the other ones
size the heatsinks in them to just barely dissipate enough
heat for just long enough for the size battery they put in them.
Without serious modifications to these units running them
continuously at anything like full power and lots of parts will
melt. Another problem is that the pseudo-sine wave that
these things generate have fast rise times and the resulting
noise is very hard to get out of the rest of the audio chain.
SMPS supplies running at 40khz are the only way to go.
They are NOT easy to build.
Go buy a ready made unit. (jbl et all)
also for the power supply, im thinking of getting a 1kva ups, ripping the battery out, connecting a 12V, 25A/H battery, inverting the dc voltage into AC, then rectifying it to obtain the required current and voltage...
most of the apc (brand name) and a lot of the other ones
size the heatsinks in them to just barely dissipate enough
heat for just long enough for the size battery they put in them.
Without serious modifications to these units running them
continuously at anything like full power and lots of parts will
melt. Another problem is that the pseudo-sine wave that
these things generate have fast rise times and the resulting
noise is very hard to get out of the rest of the audio chain.
SMPS supplies running at 40khz are the only way to go.
They are NOT easy to build.
Go buy a ready made unit. (jbl et all)
so we didnt see any schematics yet?
any ones using bridge/parallel lm3886 min. 200w rms driving
4 ohm load?
any ones using bridge/parallel lm3886 min. 200w rms driving
4 ohm load?
1000W amp
This is my first post so be patient.
This projest sound interesting but the power supply seems to be more difficult than the amp.
Some good apnotes on paralleling amplifiers can be found on the Apex site...They also have some very large hybrid amps and some class D modules (ie 800W) Expensive parts for hobby but the notes are good. http://eportal.apexmicrotech.com/mainsite/index.asp
Now, the power supply:
At 1000W o/p you would need at least 1600W DC power. ( this depends how close to the rails the output swings)
A SMPS at 85% efficiency would require 1880W of DC input.
At 13.8VDC this would be 136 Amps of battery current...
An ineresting project indeed
🙂
This is my first post so be patient.
This projest sound interesting but the power supply seems to be more difficult than the amp.
Some good apnotes on paralleling amplifiers can be found on the Apex site...They also have some very large hybrid amps and some class D modules (ie 800W) Expensive parts for hobby but the notes are good. http://eportal.apexmicrotech.com/mainsite/index.asp
Now, the power supply:
At 1000W o/p you would need at least 1600W DC power. ( this depends how close to the rails the output swings)
A SMPS at 85% efficiency would require 1880W of DC input.
At 13.8VDC this would be 136 Amps of battery current...
An ineresting project indeed
🙂
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