I found this thread while searching for something else, anyways there is a 3M product called "Flourinert" which although kind of expensive, can be used to immerse elctronics. if you are still interested.
http://www.3m.com/product/l_index/Liquid,_3M(TM)_Fluorinert(TM)_Electronic_(BF)_00.jhtml
http://www.3m.com/product/l_index/Liquid,_3M(TM)_Fluorinert(TM)_Electronic_(BF)_00.jhtml
Isolationist tendencies
Peter
Have you considered mounting the chip on a magnetically levitating platform ?
I envisaged the floating plate being either the whole heatsink or say being acrylic and having the heatsink attached. Perhaps the ideal would be to have the smallest mass floating section to minimize the necessary magnet strength needed, ie a standard vaned copper heatsink.
Here is an interesting discussion an realisation of this.
http://www.tnt-audio.com/accessories/relaxa1_e.html
regards
Simon
Peter
Have you considered mounting the chip on a magnetically levitating platform ?
I envisaged the floating plate being either the whole heatsink or say being acrylic and having the heatsink attached. Perhaps the ideal would be to have the smallest mass floating section to minimize the necessary magnet strength needed, ie a standard vaned copper heatsink.
Here is an interesting discussion an realisation of this.
http://www.tnt-audio.com/accessories/relaxa1_e.html
regards
Simon
how about this?
I dont know if its been mentioned on this thread yet (just quickly flicked through) but you can get a transformer fluid called Midel 7131 (www.midel.com) made from a synthetic ester rather than mineral oil. Its non toxic, biodegradable, flame retardant and I saw a site where some guys used it to liquid cool a motherboard with success.
Not sure how much it would cost to buy, although I suspect it would be less than Fluorinert
Anyway, good luck with your projects
Pete.
I dont know if its been mentioned on this thread yet (just quickly flicked through) but you can get a transformer fluid called Midel 7131 (www.midel.com) made from a synthetic ester rather than mineral oil. Its non toxic, biodegradable, flame retardant and I saw a site where some guys used it to liquid cool a motherboard with success.
Not sure how much it would cost to buy, although I suspect it would be less than Fluorinert
Anyway, good luck with your projects
Pete.
Re: Re: this is first
Originally posted by SkinnyBoy
I made an oil cooled amp.. sortof...
its the basic circuit from the LM3886 data sheet...
without the filter caps near the chip...
(4 resistors, a capacitor, and the chip) all are mounted over the chip....
I am using CAT 5 cable to apply power, and feed the signal into the chip..
as well as get the speaker output from it.
so...
I have a piece of metre long CAT 5 solid core cable, connected to a little black box with a few resistors and a capacitor....
connected to the end of this piece of cable is a powersupply (consisting of a transformer, bridge, and 10,000uF per rail) there is a speaker terminal....
and a audio input socket..
(sorry no pictures) the chip, capacitor, and resistors are all submerged in a jar of oil (cooking oil)
this oil is then stirred with a magnetic stirrer..
All experiments will not turn out as an improvement.
But no experimenting will not discover much.
You've got to love the spirit of an exploring mind!
MantramAudio said:
Originally posted by SkinnyBoy
I made an oil cooled amp.. sortof...
its the basic circuit from the LM3886 data sheet...
without the filter caps near the chip...
(4 resistors, a capacitor, and the chip) all are mounted over the chip....
I am using CAT 5 cable to apply power, and feed the signal into the chip..
as well as get the speaker output from it.
so... I have a piece of metre long CAT 5 solid core cable, connected to a little black box with a few resistors and a capacitor....
connected to the end of this piece of cable is a powersupply (consisting of a transformer, bridge, and 10,000uF per rail) there is a speaker terminal....
and a audio input socket..
(sorry no pictures) the chip, capacitor, and resistors are all submerged in a jar of oil (cooking oil)this oil is then stirred with a magnetic stirrer..
SkinnyBoy said:
SkinnyBoy said:I'm actually not planning on doing anything more than I have already... no time... and its really quite pointless...
All experiments will not turn out as an improvement.
But no experimenting will not discover much.
You've got to love the spirit of an exploring mind!
Peter Daniel said:I'm working on a new project, where GC chip would not be mounted to the heatsink (after reading pads thread I have some reservations about mounting the chip to piece of metal
There are possible advantages to this approach of heat dissipation, mainly better damping and avoiding vibration pick up from the chassis. It is also more original way of building an amp, as I promised the members of AA to come up with something refreshing and original
Hi Peter,
I havn't read all the replies so sorry if I'm repeating someone elses ideas.
If you use water it will find its way to your pins somehow and corrode/short them.
Where I work we are often building instrumentation for under water measurements (Freshwater and saltwater).
We flood the entire pcb housing with clear mineral oil or silicon oil. This doesnt seem to affect any of the electronic components even in the long term.
The distance between the pins in most chips (even SMD's) is great enough that the dielectric properties of the oil definitely wont be a problem.
The only problem I have seen so far in this kind of stuff is that a waterproof boot on a toggle switch went hard, probably because the oil sucked out the plasticizer from its pvc rubber.
It is really messy stuff to work on!
As a last note: Oil or water.. or even engine coolant wont move heat as quick as aluminium or copper
Re: Re: Is LM3875 chip waterproof?
What I know, isnt aluminium quicker than copper moving heat?
My guess is also that the difference between copper/aluminium is not so very big.
They are both in same magnitude, compared to other stuff?
Sometimes we want to keep temperature, so it does not change too quickly.
Keep a stable temp.
What stuff could be used to keep stable working temp in a semiconductor, transistor or chip?
Anybody know some website
where quality of different metals and other non-metal materials is listed?
Coefficients and such.
filgor said:
What I know, isnt aluminium quicker than copper moving heat?
My guess is also that the difference between copper/aluminium is not so very big.
They are both in same magnitude, compared to other stuff?
Sometimes we want to keep temperature, so it does not change too quickly.
Keep a stable temp.
What stuff could be used to keep stable working temp in a semiconductor, transistor or chip?
Anybody know some website
where quality of different metals and other non-metal materials is listed?
Coefficients and such.
thanks, Peter Daniel
from this table I get ranking of metals to use in heatsink would be:
Thermal Conductivity (W/m K)
1. silver 406
2. copper 385
3. aluminium 205
4. brass 109
5. steel 50
if regardless of cost
we should use silver heatsinks
For metals, the thermal conductivity is quite high,
and those metals which are the best electrical conductors are also the best thermal conductors.
At a given temperature, the thermal and electrical conductivities of metals are proportional,
but raising the temperature increases the thermal conductivity
while decreasing the electrical conductivity.
from this table I get ranking of metals to use in heatsink would be:
Thermal Conductivity (W/m K)
1. silver 406
2. copper 385
3. aluminium 205
4. brass 109
5. steel 50
if regardless of cost
we should use silver heatsinks
For metals, the thermal conductivity is quite high,
and those metals which are the best electrical conductors are also the best thermal conductors.
At a given temperature, the thermal and electrical conductivities of metals are proportional,
but raising the temperature increases the thermal conductivity
while decreasing the electrical conductivity.
Big caveat here, its difficult to get much convection inside metals cooling electronics. Id run coolant across/through a copper heatsink/block.
Aluminum can beat copper by weight, though not by volume.
Thermal conductivity of various compounds, sorted by volume:
Diamond >1,000, carbon nanotubes along the grain, but not across it.
> silver
> copper
> gold 317
> aluminium
> tungsten 174
> molybdenum 138
> brass
> nickel 91
> iron 81
> platinum 72
> tin 66.6
> carbon steel ~46
> lead 35
> titanium 22
> 304 stainless steel 21
> mercury 8.7
> ice 2.2
> glass ~1
> water .58
> NaK .22 @ room temperature. The other liquid metal.
> alkanes.
waterproof chip
Peter, I think it is a great idea something different. The chip itself is theroreticaly water resistant for short times, but would suffer from creepage at the pad to plastic and pins. Why not solder the chip to a coper tube with is guts inside, then seal the pin area with epoxy mount that tube inside a water/coolant filled tube with a pump. Then that tube inside another lager tube, you could make a water fall cooler I made something similar for a PC for a client once, very pretty and functional....
Peter, I think it is a great idea something different. The chip itself is theroreticaly water resistant for short times, but would suffer from creepage at the pad to plastic and pins. Why not solder the chip to a coper tube with is guts inside, then seal the pin area with epoxy mount that tube inside a water/coolant filled tube with a pump. Then that tube inside another lager tube, you could make a water fall cooler I made something similar for a PC for a client once, very pretty and functional....
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.