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Re: Help with Gauge

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  • chrisoe1
    ... I surfed the net and found these older manuals for early digital readouts. They still contain circuits for the analog part. It s all conventional stuff and
    Message 1 of 14 , May 1, 2009
      --- In VacuumX@yahoogroups.com, "Alfredo Neves" <aneves@...> wrote:
      >
      > Hi All,
      >
      > Thanks for all the replies.
      >
      > You see as I mentioned before I have been gifted the convectron 275 sensor, so the sendor part it's done.
      >
      > What I need is to make the controller (read out circuit).
      >
      > Does any one know where I could get the circuit diagrams of a Granville-Phillips Convectron Series 375 controller?
      >
      > I really enjoy building electronics and would like to build a good controller similar to a comercial unit.
      >
      > Would you be so king as to elaborate more on the "constant filament temperatures of a regulated temperature resistance circuit".
      >
      > Regards,
      >
      > Alfredo
      >
      > --- In VacuumX@yahoogroups.com, "mtuchelt" <mtuchelt@> wrote:
      > >
      > > Hello everyone
      > > I would like to share my experiences with this gauge.
      > > A very simple circuit for this gauge uses nothing more than a 9 volt three terminal voltage regulator , a 12 volt adapter, a 50k pot, and a 520 ohm resistor.
      > > Series the lamp with the 570 ohm resistor for one leg of the bridge and use the pot and a trim for the other leg.
      > >
      > > The cold resistance (20 C) of the lamps are about 270 ohms.
      > > At 200 C its about 480.
      > > Tungsten has a reasonably flat temperature /resistance coefficient of 0.0043% /C from 20 to 100, and not too far from this upto 200 C.
      > >
      > > This arrangement will not provide the constant filament temperatures of a regulated temperature resistance circuit but its not really necessary as the pressure / convection relation is not a linear one. It will need to be calibrated against a known pressure anyway.
      > >
      > > To prevent drift (not temperature compensation, that's another matter)
      > > the filament should be properly flashed. This is usually done at the factory
      > > to completely crystallize the tungsten to prevent sagging. It may not have been done properly on very inexpensive ornamental lamps. To do this connect the lamp to 200 or so volts for a brief instant to convert any fibrous tungsten to crystalline form.
      > >
      > > Another tip to reduce drift is to mechanically stabilize the filament.
      > > Open the top of the glass envelope by gently running it on a belt sander or sand paper. The hole should be about 1/4 inch diameter.
      > > Insert a small screwdriver and gently spread the filament support leads as far as possible.
      > >
      > > If the gauge is only used on the backing pump side, the lamp can be inserted directly into a piece of soft natural rubber vacuum hose and the seal is done.
      > > If exposed to Hvac, a simple fitting with a Kel-F or Viton "O" ring can be made. The glass envelope is actually very strong and can easily compress these seals to make a perfect vacuum seal, and bake able (no epoxy necessary).
      > >
      > > I have used these gauges with very good repeatability to 5e-4.
      > > Hope this helps.
      > >
      >
      I surfed the net and found these older manuals for early digital readouts. They still contain circuits for the analog part. It's all conventional stuff and from the trouble shooting and calibration instruction you may find all the info to build the analog electronics, The readout on these older system was simply an analog moving coil meter displaying the voltage between pin 1 and pin 4. Linearization was then made by calibrating the scale of the meter. In newer system a microprocessor takes care of all the calibration and other functions so digital display and programming becomes feasible.

      Good luck!

      Chris

      http://www.brooks.com/documents.cfm?documentID=4840
      http://lartpc-docdb.fnal.gov/0001/000132/007/275539-01.pdf
    • Alfredo Neves
      Chris, Great job! I had looked and could not find any schematics. Thanks, this gives me a great head start! Alfredo From: VacuumX@yahoogroups.com
      Message 2 of 14 , May 1, 2009

        Chris,

         

        Great job! I had looked and could not find any schematics. Thanks, this gives me a great head start!

         

        Alfredo

         

        From: VacuumX@yahoogroups.com [mailto:VacuumX@yahoogroups.com] On Behalf Of chrisoe1
        Sent: Friday, May 01, 2009 8:38 PM
        To: VacuumX@yahoogroups.com
        Subject: [VacuumX] Re: Help with Gauge

         




        --- In VacuumX@yahoogroups.com, "Alfredo Neves" <aneves@...> wrote:

        >
        > Hi All,
        >
        > Thanks for all the replies.
        >
        > You see as I mentioned before I have been gifted the convectron 275
        sensor, so the sendor part it's done.
        >
        > What I need is to make the controller (read out circuit).
        >
        > Does any one know where I could get the circuit diagrams of a
        Granville-Phillips Convectron Series 375 controller?
        >
        > I really enjoy building electronics and would like to build a good
        controller similar to a comercial unit.
        >
        > Would you be so king as to elaborate more on the "constant filament
        temperatures of a regulated temperature resistance circuit".
        >
        > Regards,
        >
        > Alfredo
        >
        > --- In VacuumX@yahoogroups.com,
        "mtuchelt" <mtuchelt@> wrote:
        > >
        > > Hello everyone
        > > I would like to share my experiences with this gauge.
        > > A very simple circuit for this gauge uses nothing more than a 9 volt
        three terminal voltage regulator , a 12 volt adapter, a 50k pot, and a 520 ohm resistor.
        > > Series the lamp with the 570 ohm resistor for one leg of the bridge
        and use the pot and a trim for the other leg.
        > >
        > > The cold resistance (20 C) of the lamps are about 270 ohms.
        > > At 200 C its about 480.
        > > Tungsten has a reasonably flat temperature /resistance coefficient of
        0.0043% /C from 20 to 100, and not too far from this upto 200 C.
        > >
        > > This arrangement will not provide the constant filament temperatures
        of a regulated temperature resistance circuit but its not really necessary as the pressure / convection relation is not a linear one. It will need to be calibrated against a known pressure anyway.
        > >
        > > To prevent drift (not temperature compensation, that's another
        matter)
        > > the filament should be properly flashed. This is usually done at the
        factory
        > > to completely crystallize the tungsten to prevent sagging. It may not
        have been done properly on very inexpensive ornamental lamps. To do this connect the lamp to 200 or so volts for a brief instant to convert any fibrous tungsten to crystalline form.
        > >
        > > Another tip to reduce drift is to mechanically stabilize the
        filament.
        > > Open the top of the glass envelope by gently running it on a belt
        sander or sand paper. The hole should be about 1/4 inch diameter.
        > > Insert a small screwdriver and gently spread the filament support
        leads as far as possible.
        > >
        > > If the gauge is only used on the backing pump side, the lamp can be
        inserted directly into a piece of soft natural rubber vacuum hose and the seal is done.
        > > If exposed to Hvac, a simple fitting with a Kel-F or Viton
        "O" ring can be made. The glass envelope is actually very strong and can easily compress these seals to make a perfect vacuum seal, and bake able (no epoxy necessary).
        > >
        > > I have used these gauges with very good repeatability to 5e-4.
        > > Hope this helps.
        > >
        >
        I surfed the net and found these older manuals for early digital readouts. They still contain circuits for the analog part. It's all conventional stuff and from the trouble shooting and calibration instruction you may find all the info to build the analog electronics, The readout on these older system was simply an analog moving coil meter displaying the voltage between pin 1 and pin 4. Linearization was then made by calibrating the scale of the meter. In newer system a microprocessor takes care of all the calibration and other functions so digital display and programming becomes feasible.

        Good luck!

        Chris

        http://www.brooks.com/documents.cfm?documentID=4840
        http://lartpc-docdb.fnal.gov/0001/000132/007/275539-01.pdf

        No virus found in this incoming message.
        Checked by AVG - www.avg.com
        Version: 8.0.238 / Virus Database: 270.12.6/2084 - Release Date: 05/01/09 06:17:00

      • chrisoe1
        ... Alfredo, can you open the pdf files? the schwematics are at the end section 6/ fig 6-1 and fig 6-2. If you can t find them send me an e-mail and I will
        Message 3 of 14 , May 1, 2009
          --- In VacuumX@yahoogroups.com, "Alfredo Neves" <aneves@...> wrote:
          >
          > Chris,
          >
          >
          >
          > Great job! I had looked and could not find any schematics. Thanks, this
          > gives me a great head start!
          >
          >
          >
          > Alfredo
          >
          >
          >
          >
          >
          > From: VacuumX@yahoogroups.com [mailto:VacuumX@yahoogroups.com] On Behalf Of
          > chrisoe1
          Alfredo,
          can you open the pdf files?
          the schwematics are at the end section 6/ fig 6-1 and fig 6-2.
          If you can't find them send me an e-mail and I will send them to you as as an attachment.

          Chris
          > Sent: Friday, May 01, 2009 8:38 PM
          > To: VacuumX@yahoogroups.com
          > Subject: [VacuumX] Re: Help with Gauge
          >
          >
          >
          >
          >
          >
          >
          >
          > --- In VacuumX@yahoogroups.com <mailto:VacuumX%40yahoogroups.com> , "Alfredo
          > Neves" <aneves@> wrote:
          > >
          > > Hi All,
          > >
          > > Thanks for all the replies.
          > >
          > > You see as I mentioned before I have been gifted the convectron 275
          > sensor, so the sendor part it's done.
          > >
          > > What I need is to make the controller (read out circuit).
          > >
          > > Does any one know where I could get the circuit diagrams of a
          > Granville-Phillips Convectron Series 375 controller?
          > >
          > > I really enjoy building electronics and would like to build a good
          > controller similar to a comercial unit.
          > >
          > > Would you be so king as to elaborate more on the "constant filament
          > temperatures of a regulated temperature resistance circuit".
          > >
          > > Regards,
          > >
          > > Alfredo
          > >
          > > --- In VacuumX@yahoogroups.com <mailto:VacuumX%40yahoogroups.com> ,
          > "mtuchelt" <mtuchelt@> wrote:
          > > >
          > > > Hello everyone
          > > > I would like to share my experiences with this gauge.
          > > > A very simple circuit for this gauge uses nothing more than a 9 volt
          > three terminal voltage regulator , a 12 volt adapter, a 50k pot, and a 520
          > ohm resistor.
          > > > Series the lamp with the 570 ohm resistor for one leg of the bridge and
          > use the pot and a trim for the other leg.
          > > >
          > > > The cold resistance (20 C) of the lamps are about 270 ohms.
          > > > At 200 C its about 480.
          > > > Tungsten has a reasonably flat temperature /resistance coefficient of
          > 0.0043% /C from 20 to 100, and not too far from this upto 200 C.
          > > >
          > > > This arrangement will not provide the constant filament temperatures of
          > a regulated temperature resistance circuit but its not really necessary as
          > the pressure / convection relation is not a linear one. It will need to be
          > calibrated against a known pressure anyway.
          > > >
          > > > To prevent drift (not temperature compensation, that's another matter)
          > > > the filament should be properly flashed. This is usually done at the
          > factory
          > > > to completely crystallize the tungsten to prevent sagging. It may not
          > have been done properly on very inexpensive ornamental lamps. To do this
          > connect the lamp to 200 or so volts for a brief instant to convert any
          > fibrous tungsten to crystalline form.
          > > >
          > > > Another tip to reduce drift is to mechanically stabilize the filament.
          > > > Open the top of the glass envelope by gently running it on a belt sander
          > or sand paper. The hole should be about 1/4 inch diameter.
          > > > Insert a small screwdriver and gently spread the filament support leads
          > as far as possible.
          > > >
          > > > If the gauge is only used on the backing pump side, the lamp can be
          > inserted directly into a piece of soft natural rubber vacuum hose and the
          > seal is done.
          > > > If exposed to Hvac, a simple fitting with a Kel-F or Viton "O" ring can
          > be made. The glass envelope is actually very strong and can easily compress
          > these seals to make a perfect vacuum seal, and bake able (no epoxy
          > necessary).
          > > >
          > > > I have used these gauges with very good repeatability to 5e-4.
          > > > Hope this helps.
          > > >
          > >
          > I surfed the net and found these older manuals for early digital readouts.
          > They still contain circuits for the analog part. It's all conventional stuff
          > and from the trouble shooting and calibration instruction you may find all
          > the info to build the analog electronics, The readout on these older system
          > was simply an analog moving coil meter displaying the voltage between pin 1
          > and pin 4. Linearization was then made by calibrating the scale of the
          > meter. In newer system a microprocessor takes care of all the calibration
          > and other functions so digital display and programming becomes feasible.
          >
          > Good luck!
          >
          > Chris
          >
          > http://www.brooks.com/documents.cfm?documentID=4840
          > http://lartpc-docdb.fnal.gov/0001/000132/007/275539-01.pdf
          >
          >
          >
          > No virus found in this incoming message.
          > Checked by AVG - www.avg.com
          > Version: 8.0.238 / Virus Database: 270.12.6/2084 - Release Date: 05/01/09
          > 06:17:00
          >
        • Alfredo Neves
          Chris, I ve managed to open the PDF with no problems. Again thanks for your kind effort. Alfredo From: VacuumX@yahoogroups.com [mailto:VacuumX@yahoogroups.com]
          Message 4 of 14 , May 1, 2009

            Chris,

             

            I’ve managed to open the PDF with no problems. Again thanks for your kind effort.

             

            Alfredo

             

            From: VacuumX@yahoogroups.com [mailto:VacuumX@yahoogroups.com] On Behalf Of chrisoe1
            Sent: Friday, May 01, 2009 9:24 PM
            To: VacuumX@yahoogroups.com
            Subject: [VacuumX] Re: Help with Gauge

             




            --- In VacuumX@yahoogroups.com, "Alfredo Neves" <aneves@...> wrote:

            >
            > Chris,
            >
            >
            >
            > Great job! I had looked and could not find any schematics. Thanks, this
            > gives me a great head start!
            >
            >
            >
            > Alfredo
            >
            >
            >
            >
            >
            > From: VacuumX@yahoogroups.com
            [mailto:VacuumX@yahoogroups.com] On Behalf Of
            > chrisoe1
            Alfredo,
            can you open the pdf files?
            the schwematics are at the end section 6/ fig 6-1 and fig 6-2.
            If you can't find them send me an e-mail and I will send them to you as as an attachment.

            Chris
            > Sent: Friday, May 01, 2009 8:38 PM
            > To: VacuumX@yahoogroups.com
            > Subject: [VacuumX] Re: Help with Gauge
            >
            >
            >
            >
            >
            >
            >
            >
            > --- In VacuumX@yahoogroups.com
            <mailto:VacuumX%40yahoogroups.com> , "Alfredo
            > Neves" <aneves@> wrote:
            > >
            > > Hi All,
            > >
            > > Thanks for all the replies.
            > >
            > > You see as I mentioned before I have been gifted the convectron 275
            > sensor, so the sendor part it's done.
            > >
            > > What I need is to make the controller (read out circuit).
            > >
            > > Does any one know where I could get the circuit diagrams of a
            > Granville-Phillips Convectron Series 375 controller?
            > >
            > > I really enjoy building electronics and would like to build a good
            > controller similar to a comercial unit.
            > >
            > > Would you be so king as to elaborate more on the "constant
            filament
            > temperatures of a regulated temperature resistance circuit".
            > >
            > > Regards,
            > >
            > > Alfredo
            > >
            > > --- In VacuumX@yahoogroups.com
            <mailto:VacuumX%40yahoogroups.com> ,
            > "mtuchelt" <mtuchelt@> wrote:
            > > >
            > > > Hello everyone
            > > > I would like to share my experiences with this gauge.
            > > > A very simple circuit for this gauge uses nothing more than a 9
            volt
            > three terminal voltage regulator , a 12 volt adapter, a 50k pot, and a 520
            > ohm resistor.
            > > > Series the lamp with the 570 ohm resistor for one leg of the
            bridge and
            > use the pot and a trim for the other leg.
            > > >
            > > > The cold resistance (20 C) of the lamps are about 270 ohms.
            > > > At 200 C its about 480.
            > > > Tungsten has a reasonably flat temperature /resistance
            coefficient of
            > 0.0043% /C from 20 to 100, and not too far from this upto 200 C.
            > > >
            > > > This arrangement will not provide the constant filament
            temperatures of
            > a regulated temperature resistance circuit but its not really necessary as
            > the pressure / convection relation is not a linear one. It will need to be
            > calibrated against a known pressure anyway.
            > > >
            > > > To prevent drift (not temperature compensation, that's another
            matter)
            > > > the filament should be properly flashed. This is usually done at
            the
            > factory
            > > > to completely crystallize the tungsten to prevent sagging. It
            may not
            > have been done properly on very inexpensive ornamental lamps. To do this
            > connect the lamp to 200 or so volts for a brief instant to convert any
            > fibrous tungsten to crystalline form.
            > > >
            > > > Another tip to reduce drift is to mechanically stabilize the
            filament.
            > > > Open the top of the glass envelope by gently running it on a
            belt sander
            > or sand paper. The hole should be about 1/4 inch diameter.
            > > > Insert a small screwdriver and gently spread the filament
            support leads
            > as far as possible.
            > > >
            > > > If the gauge is only used on the backing pump side, the lamp can
            be
            > inserted directly into a piece of soft natural rubber vacuum hose and the
            > seal is done.
            > > > If exposed to Hvac, a simple fitting with a Kel-F or Viton
            "O" ring can
            > be made. The glass envelope is actually very strong and can easily
            compress
            > these seals to make a perfect vacuum seal, and bake able (no epoxy
            > necessary).
            > > >
            > > > I have used these gauges with very good repeatability to 5e-4.
            > > > Hope this helps.
            > > >
            > >
            > I surfed the net and found these older manuals for early digital readouts.
            > They still contain circuits for the analog part. It's all conventional
            stuff
            > and from the trouble shooting and calibration instruction you may find all
            > the info to build the analog electronics, The readout on these older
            system
            > was simply an analog moving coil meter displaying the voltage between pin
            1
            > and pin 4. Linearization was then made by calibrating the scale of the
            > meter. In newer system a microprocessor takes care of all the calibration
            > and other functions so digital display and programming becomes feasible.
            >
            > Good luck!
            >
            > Chris
            >
            > http://www.brooks.com/documents.cfm?documentID=4840
            > http://lartpc-docdb.fnal.gov/0001/000132/007/275539-01.pdf
            >
            >
            >
            > No virus found in this incoming message.
            > Checked by AVG - www.avg.com
            > Version: 8.0.238 / Virus Database: 270.12.6/2084 - Release Date: 05/01/09
            > 06:17:00
            >

            No virus found in this incoming message.
            Checked by AVG - www.avg.com
            Version: 8.0.238 / Virus Database: 270.12.6/2084 - Release Date: 05/01/09 06:17:00

          • mtuchelt
            You might try US patent database search. You won t get the schematics but it gives full disclosure of the operating principles . Try PN 6227056 to start and
            Message 5 of 14 , May 3, 2009
              You might try US patent database search.
              You won't get the schematics but it gives full disclosure of the operating principles .
              Try PN 6227056 to start and check [referenced by] and [references]. The inventor of this gauge was one of the inventors of the convectron gauge.
              If you are good with electronics, you may be able to design the analog interface and correction scheme with the information.
              I have built a ton of one off stuff from info from patents.
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