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Re: [GPSL] Re: Harbor Freight high vacuum pump - cheap!

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  • L. Paul Verhage
    I ve purchased some of the parts I ll need for the environmental chamber. The plan at this time is to lay the plastic jar on it s side. A pallet containing
    Message 1 of 25 , Feb 1, 2009
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      I've purchased some of the parts I'll need for the environmental chamber.  The plan at this time is to lay the plastic jar on it's side.  A pallet containing the test subject and overhead UV LEDs slides in and the lid is closed.  The top of the pallet contains a small thermometer and magnetic reed switch for the UV LEDs.  The contraption sits in an open box of dry ice and gets pumped down after the temperature drops low enough.  As it pumps down, a magnet placed on top of the jar turns on the LEDs.  A lid goes over the box to reduce heat loss and to contain parts if it decides to implode.  
       
      I'll purchase two different UV LEDs so the spectrum is covered well.
       
      Now to see if I can get someone at KATS to gently drill a hole for me.
       
      Paul  

      On Fri, Jan 30, 2009 at 1:44 PM, Dave <wa4qal@...> wrote:
      --- In GPSL@yahoogroups.com, Mike Manes <mrmanes@...> wrote:
      >
      > Unfortunately, the EOSS chamber is so big that dry ice on the
      > outside probably wouldn't draw out much heat from the DUT.  But
      > I've yet to find a component that's sensitive to both low pressure
      > and temperature simultaneously, although no doubt some do exist.

      You might try a batch of Peltier cells.  These are used in modern
      computers for CPU coolers, and they can move quite a bit of heat
      (e.g., produce quite a low temperature), although they do gobble a
      bit of power.  Make sure the hot side has a good heat-sink for
      maximum cooling, though.

      You can frequently pick them up on e-bay for a not too unreasonable
      price.

      http://en.wikipedia.org/wiki/Thermoelectric_effect

      > All you have to do next is add a mondo UV light source to make
      > a real solar-vac chamber!

      You'd need a BUNCH of them to imitate the sun.

      > 73 de Mike W5VSI

      Dave
      WA4QAL



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      --
      Onwards and Upwards,
      Paul
    • Mike Manes
      Use isoprop or ethyl alcohol as a coolant when drilling plastic. The biggest risk there is plastic melting from the friction and sticking to the bit. And keep
      Message 2 of 25 , Feb 1, 2009
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        Use isoprop or ethyl alcohol as a coolant when drilling plastic. The biggest
        risk there is plastic melting from the friction and sticking to the bit.
        And keep the chuck speed WAY down!
        Got that T-shirt, BTW :={.
        73 de Mike W5VSI

        L. Paul Verhage wrote:
        > I've purchased some of the parts I'll need for the environmental
        > chamber. The plan at this time is to lay the plastic jar on it's side.
        > A pallet containing the test subject and overhead UV LEDs slides in and
        > the lid is closed. The top of the pallet contains a small thermometer
        > and magnetic reed switch for the UV LEDs. The contraption sits in an
        > open box of dry ice and gets pumped down after the temperature drops low
        > enough. As it pumps down, a magnet placed on top of the jar turns on
        > the LEDs. A lid goes over the box to reduce heat loss and to contain
        > parts if it decides to implode.
        >
        > I'll purchase two different UV LEDs so the spectrum is covered well.
        >
        > Now to see if I can get someone at KATS to gently drill a hole for me.
        >
        > Paul
        >
        > On Fri, Jan 30, 2009 at 1:44 PM, Dave <wa4qal@...
        > <mailto:wa4qal@...>> wrote:
        >
        > --- In GPSL@yahoogroups.com <mailto:GPSL@yahoogroups.com>, Mike
        > Manes <mrmanes@...> wrote:
        > >
        > > Unfortunately, the EOSS chamber is so big that dry ice on the
        > > outside probably wouldn't draw out much heat from the DUT. But
        > > I've yet to find a component that's sensitive to both low pressure
        > > and temperature simultaneously, although no doubt some do exist.
        >
        > You might try a batch of Peltier cells. These are used in modern
        > computers for CPU coolers, and they can move quite a bit of heat
        > (e.g., produce quite a low temperature), although they do gobble a
        > bit of power. Make sure the hot side has a good heat-sink for
        > maximum cooling, though.
        >
        > You can frequently pick them up on e-bay for a not too unreasonable
        > price.
        >
        > http://en.wikipedia.org/wiki/Thermoelectric_effect
        >
        > > All you have to do next is add a mondo UV light source to make
        > > a real solar-vac chamber!
        >
        > You'd need a BUNCH of them to imitate the sun.
        >
        > > 73 de Mike W5VSI
        >
        > Dave
        > WA4QAL
        >
        >
        >
        > ------------------------------------
        >
        > Yahoo! Groups Links
        >
        >
        > mailto:GPSL-fullfeatured@yahoogroups.com
        > <mailto:GPSL-fullfeatured@yahoogroups.com>
        >
        >
        >
        >
        >
        > --
        > Onwards and Upwards,
        > Paul
        >

        --
        Mike Manes mrmanes@... Tel: 303-979-4899
        "Things should be made as simple as possible, but not more so."
        A. Einstein
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