Hi Mega Speaker,
this could be a bit too much. 56watts / fet is not really healthy.
You will need 1.8kW transformers per channel (at least!) and you will have to dissipate the 1.8kW from both channels somewhere.
A radiator outside your house (in Summer) and inside (in Winter) would be an idea....
William
this could be a bit too much. 56watts / fet is not really healthy.
You will need 1.8kW transformers per channel (at least!) and you will have to dissipate the 1.8kW from both channels somewhere.
A radiator outside your house (in Summer) and inside (in Winter) would be an idea....
William
I'm just seeing how far you can theoretically go with this. The first iteration of this design would likely have much lower dissipation, based on PS capability I currently have. I appreciate the help to all while I think/type out loud here.
When we enter water cooling land, wouldn't the main focus be on keeping junction temps low? In the case of 3GPM: 0.007C/W, and current sheet data, junction temps are at 80C. Maybe this could be lower as the cooling apparatus design that I'm proposing would be incredibly robust.
When we enter water cooling land, wouldn't the main focus be on keeping junction temps low? In the case of 3GPM: 0.007C/W, and current sheet data, junction temps are at 80C. Maybe this could be lower as the cooling apparatus design that I'm proposing would be incredibly robust.
Hi,
it all depends on the Rth of the junction wich certainly has a bit of tolerance. I don´t know how much these are and how reliable the 0,83°K/W are.
The possibilities with watercooling are very nice and yes if you can keep the temp down you could probably do 50 or even more watts per fet.
I just wanted to point out that you have to get rid of the 1.8kW of heat you are generating. MAybe you can sell it to the neighbours?
William
it all depends on the Rth of the junction wich certainly has a bit of tolerance. I don´t know how much these are and how reliable the 0,83°K/W are.
The possibilities with watercooling are very nice and yes if you can keep the temp down you could probably do 50 or even more watts per fet.
I just wanted to point out that you have to get rid of the 1.8kW of heat you are generating. MAybe you can sell it to the neighbours?
William
sorry, one dumb question:
is the Vishay part the same as IRF (just like motorola and On seiconductor) or it is a different device (like the Fairchild par and IRF part)?
Because i am searching for the FC part but i only can find the Vishay part at maximum.
§§In caase the Vishay wsouldn't have the same characteristics as the FC one, where would you guys suggest to get this FC parts from? (i'm from Europe and FC doesn't directly sell to customers and foremost the parts on the website seems to be a little pricy!)
is the Vishay part the same as IRF (just like motorola and On seiconductor) or it is a different device (like the Fairchild par and IRF part)?
Because i am searching for the FC part but i only can find the Vishay part at maximum.
§§In caase the Vishay wsouldn't have the same characteristics as the FC one, where would you guys suggest to get this FC parts from? (i'm from Europe and FC doesn't directly sell to customers and foremost the parts on the website seems to be a little pricy!)
Now there's a great idea! I could get paid to listen to music.
We have a electric heat here in my condo, as the amp goes on I could turn the heat off, and probably heat a few rooms in the process. Much cheaper than turning on all the baseboard heaters in each room. Of course this is only beneficial in the winter months.Junction temps will shiver at the sight of this
thanks guys i'll check that out.
Just one more question:
i'm going to buy the FC parts from them, and since i'm sure there will be some shipping charges...since i have also noticed that they have the Dale metal resistors, here is my question:
i remember Nelson saying that these Metal Dale resistors have good performance/price rate...and i remember he specifically suggested one type though (i think, the 1W version....but i'm not sure) : which one was it?
Do they have that resistors or you guys suggest me to get that one from another store?
Thanks in advance.
Just one more question:
i'm going to buy the FC parts from them, and since i'm sure there will be some shipping charges...since i have also noticed that they have the Dale metal resistors, here is my question:
i remember Nelson saying that these Metal Dale resistors have good performance/price rate...and i remember he specifically suggested one type though (i think, the 1W version....but i'm not sure) : which one was it?
Do they have that resistors or you guys suggest me to get that one from another store?
Thanks in advance.
Stefanoo-
I believe you are referring to the Vishay/Dale RN type resistors. 1/4 watt resistors are the standard for most parts needed on the boards. The RN resistors are non-magnetic. I have a whole pile of parts on my table, the only resistors that are non-magnetic are the Vishay Dale RN's and the RL's. The RL's are basically the same as the RN, one difference is they have colored marking bands and look pretty, and mostly are rated 1/2 watt in the same size package as the 1/4 watt RN's. The RN's have writing on them.
There are other really expensive non-magnetic resistors out there, but why pay the extra money?
JJ
I believe you are referring to the Vishay/Dale RN type resistors. 1/4 watt resistors are the standard for most parts needed on the boards. The RN resistors are non-magnetic. I have a whole pile of parts on my table, the only resistors that are non-magnetic are the Vishay Dale RN's and the RL's. The RL's are basically the same as the RN, one difference is they have colored marking bands and look pretty, and mostly are rated 1/2 watt in the same size package as the 1/4 watt RN's. The RN's have writing on them.
There are other really expensive non-magnetic resistors out there, but why pay the extra money?
JJ
Mouser has them -- your memory is good. I am expecting a small bundle of them to arrive today from Mouser. 21 cents each (US$) for the 1/2 watt RL's.
I forgot to mention -- they are brown and the RN'slook like tiny little wienerschnitzels. The RL's look like wienerschnitzels topped with mustard, ketchup, and mayonnaise.
JJ
I forgot to mention -- they are brown and the RN'slook like tiny little wienerschnitzels. The RL's look like wienerschnitzels topped with mustard, ketchup, and mayonnaise.
JJ
OK, watercooling is taking a back seat for now. I need a little help making sure my current sinks that I have are up to the task, and to make sure I have the correct data entered.
I have four of these per channel at a length of 12" my sink
Aleph setup:
+/-45V
12 fets
set at 4 amps
360W diss/ch
Each sink disspiates 90W with 3 fets. Based on the previous link, and my sink @ 12", we'll say each sink's °C/W is roughly 0.25. So with four sinks per, going back to William's Aleph Power sheet, do I enter 0.25/4 = 0.0625. Is this the Rthh-a (0.0625) of the amplifier as a whole, and is this the figure I enter into the sheet?
-john
I have four of these per channel at a length of 12" my sink
Aleph setup:
+/-45V
12 fets
set at 4 amps
360W diss/ch
Each sink disspiates 90W with 3 fets. Based on the previous link, and my sink @ 12", we'll say each sink's °C/W is roughly 0.25. So with four sinks per, going back to William's Aleph Power sheet, do I enter 0.25/4 = 0.0625. Is this the Rthh-a (0.0625) of the amplifier as a whole, and is this the figure I enter into the sheet?
-john
John-
Are you saying you are going to use 48" of this sink per channel, dissapating 360 watts (8 amps total, 45 volts)? My totally unscientific guess is that this will be totally useless as a pizza warmer, but your FETS will last a long, long time.
JJ
okay, some of my estimate is based on experience, not totally unscientific.
Are you saying you are going to use 48" of this sink per channel, dissapating 360 watts (8 amps total, 45 volts)? My totally unscientific guess is that this will be totally useless as a pizza warmer, but your FETS will last a long, long time.
JJ
okay, some of my estimate is based on experience, not totally unscientific.
I know they can safely dissipate lots of heat, close to 500watts. I'm trying to get a highly accurate read on them, to find max allowable dissipation while keeping junction temps happy. Safe is generally good, but its not necessarily fun.
One Channel:
4 sinks per (each @ 9.75"W x 2.28"H x 12"L)
4 amps bias per
One Channel:
4 sinks per (each @ 9.75"W x 2.28"H x 12"L)
4 amps bias per
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