[Halld-controls] Coil inductances and plans for the quench detector

[Elliott Wolin]

Hi,

Floyd's spreadsheet dated 17-Mar-2011 shows the inductances below.  I'm 
not sure whether these account for the coil ordering 2-1-3-4 since the 
table is in 1-2-3-4 order, but I think Floyd told me the values were 
calculated with the coils in the correct order.  These do not include 
effects of the extra cladding, but George says this is a small effect.  
Our experience from the coil test is that the calculations are good to 
about 10%.  Inductance in Henry's:

coil 1             coil 2           coil 3          coil 4
7.1983          4.1534         4.1166       9.6083

Coils 1 and 4 balance with ratio 1.33, well within the range of the 
Danfysik QD (with appropriate modifications).  Coils 2 and 3 are well 
matched.  Coils (1+2) balance (3+4) with ratio 1.21.

Thus I conclude there should be no problem using the Danfysik QD for the 
full solenoid.

We are planning on using three QD channels:

channel 1 - coil 1 vs 4
channel 2 - coil 2 vs 3
channel 3 - (1+2) vs (3+4)   (for redundancy)

Finally, the PLC will be programmed to act as a redundant QD using a 
different technology, one that involves many more components and PLC 
programming, of course.

Comments are welcome...

Thanks,


-- 

				Sincerely,
					Elliott


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  Those raised in a morally relative or neutral environment will hold
		    no truths to be self-evident.
				

Elliott Wolin
Staff Physicist, Jefferson Lab
12000 Jefferson Ave
Suite 8 MS 12A1
Newport News, VA 23606
757-269-7365

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