EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: coppercone2 on December 13, 2024, 04:36:24 pm
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Most resistors are some kind of winding. Metal oxide, films, wirewound.. all have a helix structure
Which resistors are uniform. Composition resistors (ceramic, carbon) are one.
Are there others?
i.e. making a resistor controlled by deposition thickness only
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Some carbon film TH resistors are not helixed (low resistance, high resistivity).
For high-power RF applications, carborundum ("Globar") SiC resistors can be non-helixed.
The Vishay RNC90 metal-foil resistors have a planar pattern that is "non-inductive" due to a serpentine pattern.
[edit: changed RC90]
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Most resistors are some kind of winding. Metal oxide, films, wirewound.. all have a helix structure
Which resistors are uniform. Composition resistors (ceramic, carbon) are one.
Are there others?
i.e. making a resistor controlled by deposition thickness only
Look for "pulse" or "surge" resistant/tolerant thick-film resistors. Those want to avoid narrow bottlenecks that could become hotspots, so as I understand it, they do indeed work on the volume resistivity of the resistive thick film. I don't know whether they laser-trim those or not, and if they do, whether it's done the same way as on thin-film resistors.
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The Vishay RC90 metal-foil resistors have a planar pattern that is "non-inductive" due to a serpentine pattern.
You sure about that model number? Google finds nothing at all for "vishay" "RC90" resistor.
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Specialty RF resistors are AFAIK structured in such a way that they are a resistive line. These fellas are a tad extreme, but they do get the point across: https://www.vishay.com/en/product/53086/ (https://www.vishay.com/en/product/53086/)
Then there are special pulse rated resistors such as these monstrosities: https://www.hvproducts.de/wp-content/uploads/2021/04/washer_resistor.pdf (https://www.hvproducts.de/wp-content/uploads/2021/04/washer_resistor.pdf) . Ceramic composite are another material that's used in that way and also use their whole mass as a resistor.
And of course higher current shunts - pretty much a slab of metal.
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The Vishay RC90 metal-foil resistors have a planar pattern that is "non-inductive" due to a serpentine pattern.
You sure about that model number? Google finds nothing at all for "vishay" "RC90" resistor.
I believe he meant RNC90.
Datasheet:
https://www.digikey.com/htmldatasheets/production/1313242/0/0/1/rnc90x-z-foil-mil.html (https://www.digikey.com/htmldatasheets/production/1313242/0/0/1/rnc90x-z-foil-mil.html)
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Oops--I corrected my post.
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that looks like a creative way to make a flat spiral