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2. To install an early 5 speed transmission into a 1981 (&
later) bike means a different input shaft on the transmission is
needed; and, you will have to re-shim the transmission, etc.
It will then work OK. Without hesitation we have recommended Avery Appliance Service to… Deal with a company that is well
established and known for the work they have completed in their industry - a commercial entity, for instance -
and who can produce proof that other clients have
positive feedback about their service and knowledge. Not wanting to test this under vacuum (in part because my vacuum plumbing isn't ready and to avoid possible damage to my limited
collection of ion gauge tubes), I decided that it would
be nice to have a means of simulating an ion gauge tube
without an ion gauge tube since there is no way to power one without a vacuum below
about 1x10-3 Torr. While designed specifically for the GP-270, this basic approach should work
for other ion gauge controllers.
Attach the auto head light bulb to the filament pins of the ion gauge tube
connector. The circuit I'm going to build simulates the behavior of the common Bayard-Alpert (hot filament) ion gauge tube using light bulbs and
photodiodes. The MKS-909 operates exactly like other ion gauges based on the
Bayard-Alpert except that everything is miniaturized.
While many common ion gauges consist of a (usually) fragile
glass tube sensor and separate display/readout, the MKS-909 MIG (Miniature
Ion Gauge) Transducer puts all of that in a compact relatively robust unit with overall dimensions less the 3x4x5 inches and weighing in at about 1 pound
- smaller and lighter than the typical ion gauge tube in protective enclosure alone.
This provides both a load to test the filament power supply as well as a warmup
delay (due to its filament heating) to test the interlock circuits of the ion gauge controller.
The MKS-909 contains a stainless steel ion gauge "tube" (replaceable)
and complete electronics to drive it that runs on 24 VDC.
A photodiode monitoring the output of the light bulb drives
a current source which simulates the emission current of the ion gauge tube.
The ion gauge tube filament is a single filament 12 V auto head light
bulb. Having done preliminary testing of my turbo pump (see
the section: A Small High Vacuum System), I acquired a Granville-Phillips model 270 ion gauge
controller (GP-270). Where the unit also includes a thermocouple vacuum gauge or gauges, these can be tested separately either using a tester or under vacuum, and then with the ion gauge section.
The simulated emission current passes through the LED of an opto-coupler whose photodiode is used to provide the simulated
ion current from the ion gauge collector electrode to the high sensitivity (electrometer) amplifier
of the controller. Power down and make sure the voltages on all the ion gauge tube
pins have dropped to near zero. Depending on the design of the controller, the actual
voltages may vary but their difference should
be close to the spec for the ion gauge tube - typically about 150
VDC positive on the grid. The operation manual can be downloaded via the MKS Instruments
Web site but a Web search for "HPS Series 909 Miniature Ionization Gauge"
should return a direct link. The manual includes complete programming
information.
But if you've forgotten how it works, there's even an instant theory section in the manual.
Even if they had totally separate terminals, there might be some
thermionic emission or discharge current flow between the two filaments of the light bulb
(depending on whether it was evacuated or gas-filled).
Note that a dual beam head light bulb CANNOT be used
because the two filaments aren't isolated (for filament and
grid). Install the 100 ohm resistor or your second auto head light bulb between the two grid pins.
A second light bulb is used for the grid to test the "degas" function. Power up and test out the degas function. Adjustments permit the "sensed" pressure to be varied to test the
controller's response on each range and its autoranging circuits.
Without feedback (filament current to emission current),
it may not be possible to keep it on but there may be
a range of positions of the external pot and/or emission pot where
the brightness of the filament can be varied. For example, exposure to increased insecticide concentrations
may lead to elevated tissue concentrations, respiratory distress, and changes in development.
If you're having trouble with a machine but aren't sure if, for example, you need to get a washing machine repair or if you should just buy
a new washer, appliance professionals will be able
to asses the problem and provide you with the information that you need to make a decision.
My website; "http://Www.Register.Sblinks.net/News/appliance-repair-service-in-calgary/ |
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