Cloud Chamber with peltier coolers.

Has anyone made a cloud chamber with peltier coolers.
I have tried and cant quite get cold enough. it worked once but it was too erratic to be used in a classroom. (not cole enough.
I did use two coolers on top of each other.
Cheers
Eamonn
 
Same. tried two coolers and a big CPU fan, but couldnt get the temperature down low enough.
I'm going to try again with a different container/plate arangement.
 
I think that this is a difficult problem. The 'top' cooler has to move a small amount of heat from its upper surface to its lower surface. This heat, plus all the heat produced by the top cooler, has to be dissipated from its lower surface. All this heat has to be moved by the 'bottom' cooler from its upper surface to its lower surface. Finally, this heat, plus all the heat produced by the bottom cooler, has to be dissipated from its lower surface. This requires a big heat-sink and fan.

When you put in all the figures from the manufacturers' data, the result is not encouraging. Although a cooler may have a certain temperature differential between the 'hot' and 'cold' sides, as more heat needs to be transferred this differential is reduced. The choice of each cooler becomes critical. The top one needs to be much smaller than the bottom one.

A couple of random ones off e-bay is likely to be disappointing. It is easy to get a situation where the top one produces so much heat that the bottom one has no temperature differential at all.

My thoughts are that a water-cooled CPU heat-sink connected to a lab tap would dump a huge quantity of heat down the sink while remaining somewhat below ambient temperature.

It would be much better if a single stage cooler were to suffice. A clearly crazy implementation of this can be found: https://www.cloudylabs.fr/wp/watercool/ but it should be possible to build a somewhat smaller version.
 
I think that this is a difficult problem. The 'top' cooler has to move a small amount of heat from its upper surface to its lower surface. This heat, plus all the heat produced by the top cooler, has to be dissipated from its lower surface. All this heat has to be moved by the 'bottom' cooler from its upper surface to its lower surface. Finally, this heat, plus all the heat produced by the bottom cooler, has to be dissipated from its lower surface. This requires a big heat-sink and fan.

When you put in all the figures from the manufacturers' data, the result is not encouraging. Although a cooler may have a certain temperature differential between the 'hot' and 'cold' sides, as more heat needs to be transferred this differential is reduced. The choice of each cooler becomes critical. The top one needs to be much smaller than the bottom one.

A couple of random ones off e-bay is likely to be disappointing. It is easy to get a situation where the top one produces so much heat that the bottom one has no temperature differential at all.

My thoughts are that a water-cooled CPU heat-sink connected to a lab tap would dump a huge quantity of heat down the sink while remaining somewhat below ambient temperature.

It would be much better if a single stage cooler were to suffice. A clearly crazy implementation of this can be found: https://www.cloudylabs.fr/wp/watercool/ but it should be possible to build a somewhat smaller version.
Thanks for the info. I did use a water cooler with pump that is used for computer cpu. I took the fan off the heat exchanger and dunked it in a container of ice. (not sure if that was the better than with the fan but it seemed logical to me) but it still didnt get cold enough. I think its doable with the right combination of coolers( or maybe just the one like you said. ) I might get back to it after the holidays.
 

STEMTech

Dave
This is mine. I made it during the first lockdown. I used a double layer Peltier module and I get about -30C. There is an LED under the petri dish (toggle switch) which shines through a hole in the cotton pad. There is also a ht generator (red button) from a hand-held fly swatter which improves the ionisation. It draws 15A at 15V and works well. It is noisy so I'm thinking of trying a water cooled version using CPU liquid cooler. I used lots of foam insulation, which I think is vital, otherwise efficiency plummets!
Peltier.jpg
 

STEMTech

Dave
The invertor from the fly swatter is in the blue box. There is a DC-DC convertor to drop the 15V down to 3V to run it. You could use a linear voltage reg instead.
My prototype used a half pint plastic beer cup as the chamber. In the bottom of the cup (the narrow end) was some absorbent material, held in place by a circle of wire mesh. The output from the fly swatter invertor (around 700VDC) went between this mesh and the base of the chamber, which is a copper disc painted black. This disc sits on the Peltier module. The version in the picture uses a glass evaporating dish. I wasn't brave enough to drill a hole in it so I put some copper tape on the top of it instead, under the petri dish. It is not so effective there because the glass is such a good insulator, but glass gives a much better view of the inside of the chamber than with the plastic cup. I will eventually put the mesh inside the chamber. It makes a big difference. It increases the likelihood of ionisation.
Initially I used a green line-laser to illuminate a horizontal plane of the vapour from one side, and it gave good contrast but was too powerful to bring into school. I settled for a 1W white led instead. The power supply is a 15V led lighting supply which will give 20A. They are cheap, but I had to put it in an enclosure with switches and fuses for safety.
 
The invertor from the fly swatter is in the blue box. There is a DC-DC convertor to drop the 15V down to 3V to run it. You could use a linear voltage reg instead.
My prototype used a half pint plastic beer cup as the chamber. In the bottom of the cup (the narrow end) was some absorbent material, held in place by a circle of wire mesh. The output from the fly swatter invertor (around 700VDC) went between this mesh and the base of the chamber, which is a copper disc painted black. This disc sits on the Peltier module. The version in the picture uses a glass evaporating dish. I wasn't brave enough to drill a hole in it so I put some copper tape on the top of it instead, under the petri dish. It is not so effective there because the glass is such a good insulator, but glass gives a much better view of the inside of the chamber than with the plastic cup. I will eventually put the mesh inside the chamber. It makes a big difference. It increases the likelihood of ionisation.
Initially I used a green line-laser to illuminate a horizontal plane of the vapour from one side, and it gave good contrast but was too powerful to bring into school. I settled for a 1W white led instead. The power supply is a 15V led lighting supply which will give 20A. They are cheap, but I had to put it in an enclosure with switches and fuses for safety.
Cheers. I'll give it a go.
 

Nick Mitchener

COMMITTEE
I made one with a liquid cooler for the peltier. I used a peltier sandwich with sealed edges that I bought in the US so it is a much higher spec than the low cost chinese ones you get on ebay. Has worked very well.

When I get around to rebuilding it (the plastic container eventually crazes) I will put a copper disc on top of the peltier to increase the cooled area. Mine gets down to -26 deg C
 
I made one with a liquid cooler for the peltier. I used a peltier sandwich with sealed edges that I bought in the US so it is a much higher spec than the low cost chinese ones you get on ebay. Has worked very well.

When I get around to rebuilding it (the plastic container eventually crazes) I will put a copper disc on top of the peltier to increase the cooled area. Mine gets down to -26 deg C
Thanks Nick. do you have a link or the specs of the peltier you used.
 

Nick Mitchener

COMMITTEE
It was several years ago but when I retired I brought the invoice home with me, I will dig it out. I have a new job in Sept, they asked a few years ago about how to make one but baulked at the price of the peltier and used a cheaper one, they never got it to work properly.
 
It was several years ago but when I retired I brought the invoice home with me, I will dig it out. I have a new job in Sept, they asked a few years ago about how to make one but baulked at the price of the peltier and used a cheaper one, they never got it to work properly.
sounds like the one i have made. Got it to work once with a lot of finagling (I think thats a word).
 

Nick Mitchener

COMMITTEE
The important thing is the temp difference between the top and bottom of the chamber. The thing won't work well in a cold room, I have put a beaker of hot water on top before now to get it started.
 
Has anyone made a cloud chamber with peltier coolers.
I have tried and cant quite get cold enough. it worked once but it was too erratic to be used in a classroom. (not cole enough.
I did use two coolers on top of each other.
Cheers
Eamonn
We are lucky enough to have a Lacelles one that works very well. But I just love the way you techs are using bits and bobs to make your own. You're my kind of people. Identify the problem and look in the junk box for something that will do. This is the sort of adaptable mindset that may have saved that apollo mission.
And all through life the universe etc there will be those that have to buy the latest gadget/car/tv/phone/computer and we precious few who have the brains and pride to make our own. The garage compressor from fridge motor and calor bottle. The door operator to lift the loft ladder, the sturmey three speed to make a differential pulley winch etc.
Lets get together and beat Musk to Mars in old oil drums!
 
We are lucky enough to have a Lacelles one that works very well. But I just love the way you techs are using bits and bobs to make your own. You're my kind of people. Identify the problem and look in the junk box for something that will do. This is the sort of adaptable mindset that may have saved that apollo mission.
And all through life the universe etc there will be those that have to buy the latest gadget/car/tv/phone/computer and we precious few who have the brains and pride to make our own. The garage compressor from fridge motor and calor bottle. The door operator to lift the loft ladder, the sturmey three speed to make a differential pulley winch etc.
Lets get together and beat Musk to Mars in old oil drums!
Yes we're fortunate to have a Lascells one - although it can be temperamental and needs most of a period to get going. Love seeing home-built versions of things - so far I've only needed to make simple things like an oscillating dynamics trolley or a magnet on a spring bouncing through a coil.
 
Has anyone made a cloud chamber with peltier coolers.
I have tried and cant quite get cold enough. it worked once but it was too erratic to be used in a classroom. (not cole enough.
I did use two coolers on top of each other.
Cheers
Eamonn
I had all sorts of issues with the one I made. It was working fine to begin with but then couldn't seem to get it going again. I replaced the thermal paste with a more expensive brand (arctic silver) and replaced the quite large container with a much smaller one with a better lid and everything worked again.
 

Nick Mitchener

COMMITTEE
I used arctic silver when I made mine, expensive isn't it?

I'm told Peltiers have a limited life, the efficiency drops off. The Lascelles ones are aircooled too which doesn't help.
 
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