Search Results
7/1/2025, 11:24:52 AM
>>2928063
>Think of it as a wire running parallel to another because that is what it is
It's definitely not parallel, but you're saying there's a non-trivial parallel component because of the angle of the winding? I've never heard of that kind of current-transformer before, is there a name for it I can look up? Intuition tells me that a single layer of helical windings going down length L of the main conductor is no better than a single secondary "winding" wire that's fully parallel to the main conductor for length L, but I wouldn't know for sure.
>I have no idea what you mean here
Pic related. Turning a coaxial resistor into a triaxial one. No clue if it would improve anything though, it's just my intuition.
>What is it you expect to not work?
The narrow clearance between the coaxial faces in the image of the coaxial current shunt you posted will have significant capacitance at the impulse frequencies you talk about. Say they have an area of 5cmx10cm and a spacing of 1mm. That's 44pF, which at 0.5GHz is 7.2 ohms. I don't know how many significant figures you're trying to measure, but you may well find this RC constant to be smoothing out the sharp edges of the triggering spark-gap. Doubly so since the round-trip distance through the resistor is almost a nanosecond longer than the short capacitively-coupled distance.
>The problem might rather be that certifying an arbitary length of coax for its resistance might be a bit overboard
Did you know that you can just put a known current through the wire and measure the voltage? Could even build that into your machine.
>You'd also introduce problems when you find the length of conductor is significantly longer than your edge
Yeah ideally you'd have whatever current sensing resistor be as short as possible, but the smaller it is the more heat will build up in it, or the higher gain you'll have to put in your sense amplifier. Below 1uV absolute accuracy and GHz speeds means really expensive ICs.
Bergoz makes fast CTs
>Think of it as a wire running parallel to another because that is what it is
It's definitely not parallel, but you're saying there's a non-trivial parallel component because of the angle of the winding? I've never heard of that kind of current-transformer before, is there a name for it I can look up? Intuition tells me that a single layer of helical windings going down length L of the main conductor is no better than a single secondary "winding" wire that's fully parallel to the main conductor for length L, but I wouldn't know for sure.
>I have no idea what you mean here
Pic related. Turning a coaxial resistor into a triaxial one. No clue if it would improve anything though, it's just my intuition.
>What is it you expect to not work?
The narrow clearance between the coaxial faces in the image of the coaxial current shunt you posted will have significant capacitance at the impulse frequencies you talk about. Say they have an area of 5cmx10cm and a spacing of 1mm. That's 44pF, which at 0.5GHz is 7.2 ohms. I don't know how many significant figures you're trying to measure, but you may well find this RC constant to be smoothing out the sharp edges of the triggering spark-gap. Doubly so since the round-trip distance through the resistor is almost a nanosecond longer than the short capacitively-coupled distance.
>The problem might rather be that certifying an arbitary length of coax for its resistance might be a bit overboard
Did you know that you can just put a known current through the wire and measure the voltage? Could even build that into your machine.
>You'd also introduce problems when you find the length of conductor is significantly longer than your edge
Yeah ideally you'd have whatever current sensing resistor be as short as possible, but the smaller it is the more heat will build up in it, or the higher gain you'll have to put in your sense amplifier. Below 1uV absolute accuracy and GHz speeds means really expensive ICs.
Bergoz makes fast CTs
Page 1