I recently pulled a Varian 524-2 cold cathode gauge and controller from an old scanning electron microscope. A bit of web research suggests that the Varian 524 and 525 are similar. One PDF document suggests that you drive the tube with 2 KV and that the sensitivity is 2 amperes per Torr, from E-2 to E-6 torr.
My controller was integrated into other electronics, so I cannot simply extract what I need to create a stand alone controller. The electronic package has a meter on the front panel and a red potted assembly mounted on a PCB.
Has anybody had any experience with the Varian 524 and /or this red potted power supply thingy? I'll attempt to reverse engineer the schematic of the supporting electronics, but I'm hoping some can give me a head start.
Varian 524 Clod Cathode Gauge?
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AllenWallace
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Varian 524 Clod Cathode Gauge?
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Richard Hull
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Re: Varian 524 Clod Cathode Gauge?
Cold cathode gauges tend to be non-linear. Therefore, you should keep any supply and or readout and electronics that appeared with the gauge in the original gear. I assume you have all this at hand? If the supply "thingy" has a lead going to the gauge, then you need to figure its connections out or retain the bulk of the instrument in some fashion. These things use between 1.5 and 3KV. I think mine used about 2.4kv
A cold cathode gauge is excellent for fusor work when used in conjunction with a standard TC gauge. The combo usually offers a cheap solution to fusor vacuum work if you can't secure an adequate capacitance gauge.
I was prepared to use an old varian CC gauge with vacuum tube based metering circuit on my fusor IV, but came into posssion of a .1 torr capacitive manometer gauge which is far more accurate and not gas type sensitive. I did use the CC gauge for about two weeks and liked it a lot. I picked up the old varian CC gauge and the electronics for about $25.00 at a hamfest. I retain it now as a fall back should the capacitance gauge go south on me.
Some of this older intergrated stuff like you seem to have just needs to be noodled out on a case by case basis and requires a bit of fore knowledge of how the gauges work and a bit of electronics background.
For scrounging purposes, one needs to not only know a bit of engineering, but also a bit about how to reverse engineer.
Richard Hull
A cold cathode gauge is excellent for fusor work when used in conjunction with a standard TC gauge. The combo usually offers a cheap solution to fusor vacuum work if you can't secure an adequate capacitance gauge.
I was prepared to use an old varian CC gauge with vacuum tube based metering circuit on my fusor IV, but came into posssion of a .1 torr capacitive manometer gauge which is far more accurate and not gas type sensitive. I did use the CC gauge for about two weeks and liked it a lot. I picked up the old varian CC gauge and the electronics for about $25.00 at a hamfest. I retain it now as a fall back should the capacitance gauge go south on me.
Some of this older intergrated stuff like you seem to have just needs to be noodled out on a case by case basis and requires a bit of fore knowledge of how the gauges work and a bit of electronics background.
For scrounging purposes, one needs to not only know a bit of engineering, but also a bit about how to reverse engineer.
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment