How to drill a copper block?

No no, it is a loooong story. I want to make triode valves (or electron tubes) like the ones of the first radios and TV, and also a cathodic ray tube. For these things you need a high vacuum and one way to get it is with a oil difussion pump. The problem is you can have small droplets of oil inside the tube, so a good refirgeration is needed. The heatsing is connected in the hot side of peltiers cells and the cold side goes to another heat sink and a a fan to cool the difussion pump
 
Alberto-sp said:
No no, it is a loooong story. I want to make triode valves (or electron tubes) like the ones of the first radios and TV, and also a cathodic ray tube. For these things you need a high vacuum and one way to get it is with a oil difussion pump. The problem is you can have small droplets of oil inside the tube, so a good refirgeration is needed. The heatsing is connected in the hot side of peltiers cells and the cold side goes to another heat sink and a a fan to cool the difussion pump
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Ah, very good. I actually thought it would be a good peltier exchanger while I was reading your post, because I've been sitting on a couple of them with power supplies for a long time, just haven't found the cojones to cool a PC below ambient. That and the technology keeps changing, making that sort of cooling obsolete in the last couple of years with active TDP schemes.

Are you willing to share any more about your application? It sounds interesting.
 
I always thought peltiers were cool.

Never heard it called dubbing, thanks for that.
 
RaisedByWolves said:
I always thought peltiers were cool.
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They move thermal energy from one side to the other so. One side is cool and the other is hot. You hear about them being used to cool most often but there is no reason that they can't be used to heat something.
 
Boswell said:
They move thermal energy from one side to the other so. One side is cool and the other is hot. You hear about them being used to cool most often but there is no reason that they can't be used to heat something.
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Boswell said:
They move thermal energy from one side to the other so. One side is cool and the other is hot. You hear about them being used to cool most often but there is no reason that they can't be used to heat something.
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I got some late model range rover seats off Craigslist to put in my 30 y/o pickup so I could have 93-way adjustability, lumbar support, arm rests, ice-butt de-thawer and mud-butt dessicator. All the brains to control the various gizmos in the seats was (I found out late) integral to the RR they came out of, so I had to design my own controls for the seats. In doing so I found that the seat heating and cooling functions were done via peltier devices. One side had a heat sink surrounded by ducting that sent air toward the buttocks when the fan was on. The other side had ducting that went elsewhere (I assume exhausted out of the vehicle through the floor). Put current in one way and the butt side is cold side, with hot air exhausted; reverse the polarity and the butt side becomes the cold side, with hot air exhausted.

I thought it was pretty clever at first. Well, I suppose it still was clever, but that doesn't mean it worked well. In heating mode it worked alright but in cooling mode it just sucked... or, blew, technically. The performance was crap. It barely cooled the air by a couple of degrees. Peltier devices are very inefficient. The generate their own heat in the act of moving heat, so way more temperature rise is found on the hot side, than the temperature drop which found on the cold side. This is fine for certain applications. But not for cooling a sweaty behind.
 
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strantor said:
I got some late model range rover seats off Craigslist to put in my 30 y/o pickup so I could have 93-way adjustability, lumbar support, arm rests, ice-butt de-thawer and mud-butt dessicator. All the brains to control the various gizmos in the seats was (I found out late) integral to the RR they came out of, so I had to design my own controls for the seats. In doing so I found that the seat heating and cooling functions were done via peltier devices. One side had a heat sink surrounded by ducting that sent air toward the buttocks when the fan was on. The other side had ducting that went elsewhere (I assume exhausted out of the vehicle through the floor). Put current in one way and the butt side is cold side, with hot air exhausted; reverse the polarity and the butt side becomes the cold side, with hot air exhausted.

I thought it was pretty clever at first. Well, I suppose it still was clever, but that doesn't mean it worked well. In heating mode it worked alright but in cooling mode I just sucked... or, blew, technically. The performance was crap. It barely cooled the air by a couple of degrees. Peltier devices are very inefficient. The generate their own heat in the act of moving heat, so way more temperature rise is found on the hot side, than the temperature drop which found on the cold side. This is fine for certain applications. But not for cooling a sweaty behind.
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My 2016 f-150 is similar. Uses blowing air to heat and cool. The air just exhausts out the bottom of the seat to the cabin. Not enough to make a difference in the cabin temp though.

But it works well either way. It will chill my butt so low I often have to turn it of. It also goes up the lower back, which is far more welcome than the butt.

there was a recall for inefficient seat coolers early o in the model run. Seems they had to add a "sock" over the exhaust tube as it would often get crushed or covered by the seat cushion and dramatically worsen it's performance. Maybe have a look inside you seats and make sure the exhaust tube from the blower has an unrestricted shot to blow out the hot air from cooling?
 
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