Christer said:
Hi,
I am also sorry if I misunderstood the meaning in your earlier post.
Of course, as we have both suggested, whether or not it matters in practice, is another matter, but the colour and surface finish do have *some* affect on the heat transfer.
Interestingly, I have just looked in Farnell's catalogue, at some heat sinks which are available in both black anodised, and in plain silver, but which are otherwise identical.
Guess what, the (only) two I looked at, both show approximately an 11% 'improvement', as I anticipated.
Regards,
Edit. I have just seen Fezz's post. The ratio shown therein is 100:85.
berrylium washers
Hi, Peter
Can you share where did you buy the washers? Seems pretty difficult to get.
tks.
Ric
Peter Daniel said:
Hi, Peter
Can you share where did you buy the washers? Seems pretty difficult to get.
tks.
Ric
I got them from a local supplier Active-Future Electronics. Recently I noticed that they carry aluminum oxide instead of beryllium, although they look almost the same.
Re: Turn-on/turn-off DC transient
I'm currently using GC for mids and tweetes using them without a cap at the output, but I think is best to play safe and include the cap, albeit a big one-two octave lower that the active crosover point to not disturb it.
Not that they sound bad, but is too risky. I blowed a tweeter last night just pluging a cable.
What are you guys using for the caps ? I've read that solens seem to be out. Any recommendation on a nice cap for values of 5, 15 and 20 Mf? Are polyprop Panasonic ok? They seem to be easy to get from Digi Key.
tks.
Ric
tiroth said:
I'm currently using GC for mids and tweetes using them without a cap at the output, but I think is best to play safe and include the cap, albeit a big one-two octave lower that the active crosover point to not disturb it.
Not that they sound bad, but is too risky. I blowed a tweeter last night just pluging a cable.
What are you guys using for the caps ? I've read that solens seem to be out. Any recommendation on a nice cap for values of 5, 15 and 20 Mf? Are polyprop Panasonic ok? They seem to be easy to get from Digi Key.
tks.
Ric
beryllium-aluminum
I remember reading that beryllium is the best. I do not know anything about aluminum . Is it good?
By the way, tks for your lightning fast answer!
Cheers.
Ric
Peter Daniel said:
I remember reading that beryllium is the best. I do not know anything about aluminum . Is it good?
By the way, tks for your lightning fast answer!
Cheers.
Ric
Re: berrylium washers
Be aware that beryllium oxide (well, beryllium itself really) is quite toxic. It's ok as long as you don't break it or machine it or otherwise cause it to produce any small particles that can be breathed in.
Aluminum oxide is a safer alternative if safety is a concern.
se
Ricren said:
Be aware that beryllium oxide (well, beryllium itself really) is quite toxic. It's ok as long as you don't break it or machine it or otherwise cause it to produce any small particles that can be breathed in.
Aluminum oxide is a safer alternative if safety is a concern.
se
Re: Re: Turn-on/turn-off DC transient
--Jordan
I use auricaps, and I really like them.. I would recommend against using solens.Ricren said:
--Jordan
I think it´s no really intelligent idea to use this beryllium stuff. To use no insulation washer is better than to use anyone in terms of thermal resitance. If you need one, to use a cheap mica type and a little bit larger heatsink will have more effect on the device temperature. And Beryllium is really toxic. There are differet kinds of toxic effects of beryllium. One over short time at higher doses, dead in about 2 weeks, and one on the long run over years, often not diagnosed.
At this place is some discussion about beryllium, one of our audiofreaks community has unfortunaly a beryllium problem at the moment:
http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3729&t=114
At this place is some discussion about beryllium, one of our audiofreaks community has unfortunaly a beryllium problem at the moment:
http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3729&t=114
till said:
Yes, you are right that no insulation is better, but in the GC you have two options, isolated or not.and I found from experimentation that if you need to get high power from it, using the TF version will lead to termal shotdown sooner. So I'm in the search for the best isolator I can get.
Sorry to hear about the beryllium poisoning.
cheers
Ric
Have you ruled out nylon/teflon screws/washers? That's what I'm going to end up using.Ricren said:
--Jordan
I like to use berylium washer, because of additional thickness it gives me extra space for a feedback resistor. And I don't really give a crap about toxic danger, all of you European guys are so concerned about.😉
It is only inhalation of the dust seems to be of major issue, and I don't see how this would be possible in my procedure. I find beryllium to be the best insulator not only because of thermal resistance, but because mechanical properties as well.
It is only inhalation of the dust seems to be of major issue, and I don't see how this would be possible in my procedure. I find beryllium to be the best insulator not only because of thermal resistance, but because mechanical properties as well.
Ricren said:
Try IsoStrate from <a href="http://www.powerdevices.com/">PDI</a>. It uses a dry thermal compound applied to a Kapton MT base (which provides the electrical insulation and is one of the best thermally conductive insulators available). The dry compound flows at a certain temperature which then fills any voids.
se
Ricren,
Do you really think the gainclone will sound better with a beryllium washer than with mica, teflon, silpad or whatever?
That would be hokuspokus. Or do you want maximum power? So a bigger heatsink will have much more effect than a few promille better insulator.
Please stay away from this unnecessary and very toxic stuff. Not only you may get problems with it, also the one who will try to repair what you build some years later, because i´m sure you will not put a sheet of paper in the amp " carefull, contains toxic washers"
Do you really think the gainclone will sound better with a beryllium washer than with mica, teflon, silpad or whatever?
That would be hokuspokus. Or do you want maximum power? So a bigger heatsink will have much more effect than a few promille better insulator.
Please stay away from this unnecessary and very toxic stuff. Not only you may get problems with it, also the one who will try to repair what you build some years later, because i´m sure you will not put a sheet of paper in the amp " carefull, contains toxic washers"
Peter Daniel,
Aside from i can´t say this is ok if you think about pollution (even your amps may be junk one day and pollut enviroment), i have to say it is nuts to don´t care about a serios danger for you and everyone else / children, beginners who ever, but have a problem with stuff like this:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10630
If a DIYer, even underaged, desides to play with 120 or 220V AC, he will only harm himshelf and not other persons. And most contacts with power mains arwe without consequences, even if it COULD kill you. OK, it killed me not about some hundred times. ok?
You moderators feel the need to delete stuff like this because someone could have the idea to do dangerous thing ( a child knows power mains are dangeous) , but give advice to use beryllium, which could even kill you, or your childs if they are 12 and start to play with your old amps, and : a child doesn´t know parts in equipment could be very toxic. Something is wrong here.
I would not use it, one reason is my 3 year old son loves everything in my boxes with elektronical stuff. He would stick this mess in his mouth at a moment i don´t watch him...
Aside from i can´t say this is ok if you think about pollution (even your amps may be junk one day and pollut enviroment), i have to say it is nuts to don´t care about a serios danger for you and everyone else / children, beginners who ever, but have a problem with stuff like this:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10630
If a DIYer, even underaged, desides to play with 120 or 220V AC, he will only harm himshelf and not other persons. And most contacts with power mains arwe without consequences, even if it COULD kill you. OK, it killed me not about some hundred times. ok?
You moderators feel the need to delete stuff like this because someone could have the idea to do dangerous thing ( a child knows power mains are dangeous) , but give advice to use beryllium, which could even kill you, or your childs if they are 12 and start to play with your old amps, and : a child doesn´t know parts in equipment could be very toxic. Something is wrong here.
I would not use it, one reason is my 3 year old son loves everything in my boxes with elektronical stuff. He would stick this mess in his mouth at a moment i don´t watch him...
till said:
Looking from your point of view it is nuts to have AC receptacles in a wall because any 3 year old kid can put a screwdriver in the hole and get electrocuted.
It may become popular in your country to spread the news of the danger of such products (beryllim washers), yet I never heard about it where I live and they can be obtained in the stores.
I have my doubts if you ever tried to touch this material, not to mention use it, but from my experience it does not produce danger if handled properly. One can always use gloves and dust mask and after applying thermal paste there is completely no chance of getting in touch with a beryllium dust.
Asbestos is dangerous too, but last year, while working on aircrafts I had to replace asbestos seals on Dash 8, around engine's exhaust, because it is the only material that works in that place. Same goes for special graphite powder used to lubricate certain parts of the aircrafts. It says right on the box that it can cause cancer when inhaled. But it also says on cigarettes boxes.
I believe that smoking cigarettes presents much bigger danger.
till said:
I never gave advice to use it. I'm just saying that as long as it is available in stores I will continue to use it. You shouldn't have a problem with that.
Peter,
I don´t want to say you what to do, but i say my opinion on it, ok?
One proble is you use different scales to measure danger if you have to look on your own opinion, and what other members post. (my link to texas)
If a moderator feels the need to act in a case like this in texas, he should write into the posting "dangerous, don´t try" but not delete.
I use a device that shut power down in max 30ms if power flows not from phase to neutral but to earth ground - and i use this wall outlets with mecanical protection. You need 2 screwdriver and you need to know how it works, else you won´t get it in.
I searched for every chance to get in contact with mains as a child - but i don´t want to lose mine if they do the same.
Beryllium: some month before i didn´t knew BE is toxic. In the long process of horn building i came over the TAD drivers employing BE. A friend told me it is toxic, i searchged for every information about BE in the net - and asked a chemistry - professor at my university i know, his childs are same age like me...
He told me about the danger, i descided to buy them even if i know now BE is very toxic. But ther is a difference i (personally) think, if the reason to use it is good, and if a person handling a device will tough the toxic material or not. I dont see an advantage on using the BeO Washer against larger heatsink.
Nothing against you personally, I hope you can accept me havinmg this opinion.
I don´t want to say you what to do, but i say my opinion on it, ok?
One proble is you use different scales to measure danger if you have to look on your own opinion, and what other members post. (my link to texas)
If a moderator feels the need to act in a case like this in texas, he should write into the posting "dangerous, don´t try" but not delete.
I use a device that shut power down in max 30ms if power flows not from phase to neutral but to earth ground - and i use this wall outlets with mecanical protection. You need 2 screwdriver and you need to know how it works, else you won´t get it in.
I searched for every chance to get in contact with mains as a child - but i don´t want to lose mine if they do the same.
Beryllium: some month before i didn´t knew BE is toxic. In the long process of horn building i came over the TAD drivers employing BE. A friend told me it is toxic, i searchged for every information about BE in the net - and asked a chemistry - professor at my university i know, his childs are same age like me...
He told me about the danger, i descided to buy them even if i know now BE is very toxic. But ther is a difference i (personally) think, if the reason to use it is good, and if a person handling a device will tough the toxic material or not. I dont see an advantage on using the BeO Washer against larger heatsink.
Nothing against you personally, I hope you can accept me havinmg this opinion.
From Aavid Thermalloy site:
"Beryllium oxide insulators have a high dielectric strength, which allows safe operating voltages of 1500 volts or more. For applications involving high frequency or high pulse rate circuitry, the inherent low electrical capacitance of these insulators prevents circuit detuning and loss of signal power.
Beryllium oxide insulators have a dielectric strength of approximately 22.8 x 103 volts/mm for .81mm material (580 volts/mil for .032" material), and 17.7 x 103 volts/mm for 1.57mm material (450 volts/mil for .062 material). The thermal conductivity of beryllium oxide is 221.94 Wm-1 °C-1 (128.2 Btu/hr.ft.°F).
Beryllium oxide is chemically inert and completely safe to use in its fired state. Handling of finished parts presents absolutely no health hazards.
Beryllium oxide,however, is toxic when dust, mist or fumes containing particles small enough to enter the lungs are inhaled. Therefore, grindings, sanding, and pulverizing the material should be avoided. "
http://www.aavidprecision.com/products/standard/access/beryllium.shtml
Till,
I understand and respect your opinion, yet I'm very sceptical when somebody suddenly starts to claim that BEO washers became poisonous. I've been using them for years (before knowing they were toxic, I even tried to grind one), I handle them without gloves and never experienced any problems. As my other links show it seems like only the powdered form and dust cause real danger. For my covenience I'd rather believe the info on Aavid site which clearly states: Handling of finished parts presents absolutely no health hazards
But don't trust anybody and use your own judgement. This material can be health hazard.
"Beryllium oxide insulators have a high dielectric strength, which allows safe operating voltages of 1500 volts or more. For applications involving high frequency or high pulse rate circuitry, the inherent low electrical capacitance of these insulators prevents circuit detuning and loss of signal power.
Beryllium oxide insulators have a dielectric strength of approximately 22.8 x 103 volts/mm for .81mm material (580 volts/mil for .032" material), and 17.7 x 103 volts/mm for 1.57mm material (450 volts/mil for .062 material). The thermal conductivity of beryllium oxide is 221.94 Wm-1 °C-1 (128.2 Btu/hr.ft.°F).
Beryllium oxide is chemically inert and completely safe to use in its fired state. Handling of finished parts presents absolutely no health hazards.
Beryllium oxide,however, is toxic when dust, mist or fumes containing particles small enough to enter the lungs are inhaled. Therefore, grindings, sanding, and pulverizing the material should be avoided. "
http://www.aavidprecision.com/products/standard/access/beryllium.shtml
Till,
I understand and respect your opinion, yet I'm very sceptical when somebody suddenly starts to claim that BEO washers became poisonous. I've been using them for years (before knowing they were toxic, I even tried to grind one), I handle them without gloves and never experienced any problems. As my other links show it seems like only the powdered form and dust cause real danger. For my covenience I'd rather believe the info on Aavid site which clearly states: Handling of finished parts presents absolutely no health hazards
But don't trust anybody and use your own judgement. This material can be health hazard.
- Status
- Not open for further replies.