Variac said:
The rough surface does indeed give a larger surface but the cooling effect is smaller due to the air molecules locked in the roughness. Using a fan and making sure that air flow is not even but rather as turbulent as possible would probably help. At least this is the way I understand it. That is however completely unrelated to my sincere admiration for the nice work and craftmanship...nice.
/UrSv
PedroPO said:
Good point but I was only interested in having a good functional sink. In the other hand, the more complex your pattern the more difficult to sand cast a good looking part.
Pricewise I think these sinks cost less than a simillar commercial part, if you find one.
I appreciate you comments, it's allways nice to hear others comment on your creations even if it's a clone.
mefinnis said:Now, that there is some serious hardware ........
Congratulations
mark
Nice you drop in. Your posted information realy helped.
I looked carefully to those dificulties you faced in making your Aleph 4. If you look to the pics you will see that I put the copper traces of the power FET PCB to the outside. This helped with the soldering of the FET to the board since I first loosly mounted the transistors to the sink then I mounted the board to the leads, tighten the 6 screws and soldered, no problem.
Also took your advice and set de diff pair at the front end B2B even though at the end I decided to use separate heatsinks to avoid the insulation so spread them apart a little.
People like you is what makes this forum great
Honey? Where is the lawn furniture?
So.... where did you get the laminations to make the transformer?
Ur Sv: I am sure you are right about smooth being better. If air were trapped in the surface it would act as an insulator. Of course if you are making your own, you can just make 'em bigger!
Better start saving my drink cans.....
I once saw a demonstration by a guy showing an easy way to cast aluminum. He made a coal fire, let it get burning well, then directed the output of a vacuum cleaner as a blower to make the fire really hot. He could easily melt about a cup of aluminum in a steel pan set on the coals (the blower was on continuously). I'm sure with time a lot bigger amount could be melted.
My understanding is the wood pattern is pressed into a box of sand mixed with oil. The sand is then packed tightly around the
pattern, then the pattern is removed leaving a cavity which the aluminum is poured into. It helps removal of the pattern if it is designed so the fins taper in width. Since the pattern fins would be pressed downward into the sand, the thick base would be flush with the sand surface. The base of the finished heatsink would need to be pressed on a belt sander to make it flat.
This is a whole new world of DIY and addreses the most expensive part- the heatsinks!!
So.... where did you get the laminations to make the transformer?
Ur Sv: I am sure you are right about smooth being better. If air were trapped in the surface it would act as an insulator. Of course if you are making your own, you can just make 'em bigger!
Better start saving my drink cans.....
I once saw a demonstration by a guy showing an easy way to cast aluminum. He made a coal fire, let it get burning well, then directed the output of a vacuum cleaner as a blower to make the fire really hot. He could easily melt about a cup of aluminum in a steel pan set on the coals (the blower was on continuously). I'm sure with time a lot bigger amount could be melted.
My understanding is the wood pattern is pressed into a box of sand mixed with oil. The sand is then packed tightly around the
pattern, then the pattern is removed leaving a cavity which the aluminum is poured into. It helps removal of the pattern if it is designed so the fins taper in width. Since the pattern fins would be pressed downward into the sand, the thick base would be flush with the sand surface. The base of the finished heatsink would need to be pressed on a belt sander to make it flat.
This is a whole new world of DIY and addreses the most expensive part- the heatsinks!!
EI vs Toroidal
1St, I want to congratulate you with your creation. I think you are setting THE example for what DIY is really about. Well done.
I recently completed my Aleph30 and used a professional made toroidal. I can also hear a hum from it when I listen from about 3".
Tony: Did you build amps before and used toroidals? What is your experience between EI and toroidal transfromers?
Is it reallly a better option to use a toroidal instead of EI?
After I read these articles, I am confussed about the real pro's and con's - or the relevance of them.
Good side of EI: http://www.fsaudioweb.com/listen/cat.html (Article by Ken Stevens)
Bad side of EI: http://www.plitron.com/pages/advantag.htm
And then there is this:
http://www.rn-core.com/rncore/comparison_main.html
apassgear said:
1St, I want to congratulate you with your creation. I think you are setting THE example for what DIY is really about. Well done.
I recently completed my Aleph30 and used a professional made toroidal. I can also hear a hum from it when I listen from about 3".
Tony: Did you build amps before and used toroidals? What is your experience between EI and toroidal transfromers?
Is it reallly a better option to use a toroidal instead of EI?
After I read these articles, I am confussed about the real pro's and con's - or the relevance of them.
Good side of EI: http://www.fsaudioweb.com/listen/cat.html (Article by Ken Stevens)
Bad side of EI: http://www.plitron.com/pages/advantag.htm
And then there is this:
http://www.rn-core.com/rncore/comparison_main.html
Re: Honey? Where is the lawn furniture?
I don't know in other places but in Mexico there are stores where you can buy anything you need to rewind transformers or elec. motors and they also sell transformer lamination in any size, I guess up to EI 150 (haven't ask or seen bigger). You can also find all types of dielectric materials (insulation) plus varnish etc.
When I was building a couple of 150W 6550 tube monoblocks (long time ago and still have them) I was confronted to the issue of transformers. So I took The Radiotron handbook and start building some output tranies. But I did not have good EI laminations so I started to search for the best laminations I could get my hands on. To make the story short, I found a distributor for a US company which has a plant in Monterrey (Mx) called M.... Magnetics (Don't recall its name) which had 2% silicone iron in EI 150 form, but I had to buy a full case of it (around 50 Kg).
Since then I have been using this stock, but now I don't have much left!
Variac said:
I don't know in other places but in Mexico there are stores where you can buy anything you need to rewind transformers or elec. motors and they also sell transformer lamination in any size, I guess up to EI 150 (haven't ask or seen bigger). You can also find all types of dielectric materials (insulation) plus varnish etc.
When I was building a couple of 150W 6550 tube monoblocks (long time ago and still have them) I was confronted to the issue of transformers. So I took The Radiotron handbook and start building some output tranies. But I did not have good EI laminations so I started to search for the best laminations I could get my hands on. To make the story short, I found a distributor for a US company which has a plant in Monterrey (Mx) called M.... Magnetics (Don't recall its name) which had 2% silicone iron in EI 150 form, but I had to buy a full case of it (around 50 Kg).
Since then I have been using this stock, but now I don't have much left!
Re: Honey? Where is the lawn furniture?
The foundry I go to is a very simple setup, low tech furnaces (shop made) but as always it is somewhat involved in the way they have to clean the molten alu and the way they prepare the sand. They add bentonite and other things to the sand and when they want a good surface casting they powder some construction cement to the surface of the sand mold.
Actually they don't use oil in the sand mixture, they only add water to get a certain humidity that will "hold" the sand mold.
They don't press the pattern into the sand. What they do is lay the pattern with the fins to the top (in this case) over a bed of sand, then they put a steel frame around the pattern and start pouring sand over the top of the pattern while they compact the sand until they reach the upper level of the frame. Next they turn around the frame with all the sand and pattern attached and extract the pattern, powder the sand with cement and tun it around againt a flat bed of sand and they are ready to pour the molten metal. There are other things they do such as providing a feed entrance for the metal etc.
Want to try this?
Variac said:
The foundry I go to is a very simple setup, low tech furnaces (shop made) but as always it is somewhat involved in the way they have to clean the molten alu and the way they prepare the sand. They add bentonite and other things to the sand and when they want a good surface casting they powder some construction cement to the surface of the sand mold.
Actually they don't use oil in the sand mixture, they only add water to get a certain humidity that will "hold" the sand mold.
They don't press the pattern into the sand. What they do is lay the pattern with the fins to the top (in this case) over a bed of sand, then they put a steel frame around the pattern and start pouring sand over the top of the pattern while they compact the sand until they reach the upper level of the frame. Next they turn around the frame with all the sand and pattern attached and extract the pattern, powder the sand with cement and tun it around againt a flat bed of sand and they are ready to pour the molten metal. There are other things they do such as providing a feed entrance for the metal etc.
Want to try this?
Re: EI vs Toroidal
Good links.
First of all let me say that I'm not an EE so what I will comment are only my appreciations and don't have the knowledge to support them.
I agree with most of what Ken Stevens has to say about toroids vs. EI tranies on your first link.
It sounds intresting that many HiEnd Preamps don't use toroidals. I guess this has to do with Ken's views.
Transformers are a bag of compromises from my point of view so you have to decide which are your priorities for the application. For PSU EI transf. I try to build a quiet part so I go with a low flux 10 KGauss or less, but this means more iron, copper, output impedance of the seconday, capacitance and flux leakege for the same power. Well, I don't care much about these effects and don't even mesure them.
My final result is a quiet trany with an efficiency around 87 to 91%, depending on load, which by the way I seldom mesure. I never had problems with the tranies I build they run cool, less than 55°C, but they are usualy overdesigned for the load (NP philosophy?)
Best results are obtained when I split the secondary in half between the primary winding. but this was not done for the Aleph 4 since I was using 12 Ga. wire for the secondary and would have been difficult to connect both windings in a neat fashion.
I have no experiance with toroids, have never used one, not even had one on my hands!
On one preamp I have two US imported commercial tranies and both make a lot sound. This is a problem that many commercial products have since they try to squize the most power from the iron they use. Both of these tranies came with the Daniel Preamp kit, long been scraped, but still use the box with the tansf. and part of the circuit for a remote turn on, have been lazy to replace these.
Happy listening!
JDeV said:
1St, I want to congratulate you with your creation. I think you are setting THE example for what DIY is really about. Well done.
I recently completed my Aleph30 and used a professional made toroidal. I can also hear a hum from it when I listen from about 3".
Tony: Did you build amps before and used toroidals? What is your experience between EI and toroidal transfromers?
Is it reallly a better option to use a toroidal instead of EI?
After I read these articles, I am confussed about the real pro's and con's - or the relevance of them.
Good links.
First of all let me say that I'm not an EE so what I will comment are only my appreciations and don't have the knowledge to support them.
I agree with most of what Ken Stevens has to say about toroids vs. EI tranies on your first link.
It sounds intresting that many HiEnd Preamps don't use toroidals. I guess this has to do with Ken's views.
Transformers are a bag of compromises from my point of view so you have to decide which are your priorities for the application. For PSU EI transf. I try to build a quiet part so I go with a low flux 10 KGauss or less, but this means more iron, copper, output impedance of the seconday, capacitance and flux leakege for the same power. Well, I don't care much about these effects and don't even mesure them.
My final result is a quiet trany with an efficiency around 87 to 91%, depending on load, which by the way I seldom mesure. I never had problems with the tranies I build they run cool, less than 55°C, but they are usualy overdesigned for the load (NP philosophy?)
Best results are obtained when I split the secondary in half between the primary winding. but this was not done for the Aleph 4 since I was using 12 Ga. wire for the secondary and would have been difficult to connect both windings in a neat fashion.
I have no experiance with toroids, have never used one, not even had one on my hands!
On one preamp I have two US imported commercial tranies and both make a lot sound. This is a problem that many commercial products have since they try to squize the most power from the iron they use. Both of these tranies came with the Daniel Preamp kit, long been scraped, but still use the box with the tansf. and part of the circuit for a remote turn on, have been lazy to replace these.
Happy listening!
PedroPO said:
To much delay to get this matter out.
Sorry PedroPO, I can't take pictures of the pattern at this moment since this part is at the casting facility, they are casting 4 more pieces for Aleph X.
But let me tell you that the pattern looks identical to the sinks you see on the pictures on the first post of this thread. It does not have an "integral" plate, this is a plain piece of laminate wood
the size of the frame they will use for molding. They add this plate when molding say more than 10 parts.
On another post I mention the aprox cost not including the pattern. This came to aprox. US$85 each including the milling.
Are you building an Aleph or have plans for?
It's a pulse power switch that i bought from www.farnell.com. It's brand is Bulgin. MP0031 costed €12.78
I used a relay from Finder with this switch.
it is a dual pole NO step relay 230 VAC operated 10A that is operated with a impulse button.
P/N:26028230
www.findernet.com
costed €8
I used a relay from Finder with this switch.
it is a dual pole NO step relay 230 VAC operated 10A that is operated with a impulse button.
P/N:26028230
www.findernet.com
costed €8
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