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Sony XA5400ES fuse directionality...

Hello! I just purchased a pair of Hi-Fi Tuning (directional) fuses to upgrade the stock ones, and was wondering if any 5400 owners have discovered which way the current flows through them in this player. Do the arrows point to the right or left when viewing the fuse holders from the front of the player? Thanks for your help!
bigshutterbug

Showing 5 responses by magfan

magfan
1,583 posts
 
Hak, it's best to leave the fuse people alone. I tried reason once.....like how IS ac directional again? to no effect but getting people POd. And yes, they'll have you believe in all sorts of weird stuff. Fuse Microphonics and diode effcts. Break in of a fuse. All the rest.
Leave it be for the sake of 'peace in our time'.
magfan
1,583 posts
 
Such claims SHOULD be testable.
magfan
1,583 posts
 
You were able to consistently measure such low resistance? What kind of meter are you using?

This is how littlefuse approaches fuse resistivity:
http://www.littelfuse.com/data/en/Technical_Articles/TB98-004.pdf
magfan
1,583 posts
 
Here is the data for a 2ag, 5 amp fuse, which should be in the 'normal' range for power supplies of larger amps.
NOTE: resistance, measured cold, is <.02 ohms.

http://www.littelfuse.com/products/Fuses/2AG+(5x15mm)/208/0208005..html

Now, I have a cheap-o meter which is of low resolution. I'd like the bench meter I had at work years ago which had 8 or 9 digits of resolution.
magfan
1,583 posts
 
Are you talking damping factor change for a power supply fuse or in the protection part of the output?
One makes a little sense, the other none at all.
Sine the max current draw is isolated from the output by (presumably) a fair amount of capactitance and the max draw thru the fuse is during 'recharge' that is a little......strange.

What is the alloy of the fuse in question. I believe Littlefuse uses a Zinc alloy which this test beforehand so they get the final fuse resistivity correct per amperage.

I've used test equipment called a 4-point probe. 2 tips used to force a voltage, the other 2 tips used to measure. VERY precise readings of resistivity are possible by this method. Repeatable and process capable (in the most rigorous technical sense) such a metrology tool is used in the semiconductor industry for process evaluation.

Wouldn't wrapping the fuse element in ANYTHING result in it changing the characteristics of the fuse?

I have suggested, in the past, a test to be used for microphonics. Put the test piece in an enclosure with a speaker. Have the same circuit OUTSIDE the enclosure. Using a dual trace scope, do with / without sound subtraction of the signal. Microphonic effects should show up very easily.
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