Diode resistance question...

[jBam]

Hi all,

Reading up on diodes and their (tiny) region of useful variable resistance. I'm starting to get my head around it all, and applications in audio. Never really thought of them as anything other than: flowing, or not (until now). One thing I'm hoping to find is: is there a name for the region of Voltage between closed to fully open where the useful variable resistance is? Like "crossover voltage" or some terminology that describe how short or wide this voltage range is?? I'm hoping to search for diodes based on this characteristic online...

e.g. the forward V vs I graph for a 1n1418 seems to have 0.5-0.7V

I'm wondering if I can search for "diodes with a large crossover voltage" (with correct terminology) to understand options for tone shaping and dynamics circuits.

Suggestions on specific diodes for these purposes would also be welcomed

 

[JohnRoberts]

You appear to be confusing resistance with impedance. Diodes have a small real resistance term and a dynamic impedance that changes with forward current. Varying the current can modulate the effective impedance.

JR

 

[dmp]

You're going to love this thread

 

[jBam]

You appear to be confusing resistance with impedance. Diodes have a small real resistance term and a dynamic impedance that changes with forward current. Varying the current can modulate the effective impedance.

JR

Quite possibly John! I've been looking at those I/V graphs purely with ohms law in terms of voltage / current / resistor combinations... hmm... so... impedance... I mean... I get the idea of how / why capacitance occurs through a diode... ok: time for some more reading

Edit: and already as I think about it without reading up more, it must vary in capacitance as current increases... interesting.... now: time for that "more reading" commitment.

 

[jBam]

You're going to love this thread

Amazing!... thanks for this... a quick skim and it already looks like a gold mine!

 

[scott2000]

I was drawn into this video...

 

[jBam]

I was drawn into this video...

Thats really interesting... the dude in the video is pretty classic... kept cracking up. But yeah... very interesting. Haven't finished the full video yet, but it certainly helps to visually understand diode "recovery time"... more reading and watching for me