Are the SIT rectifiers usefull ?

[diyiggy]

Hi,
Should we use SIT diode for rectifiers ?
Any advantage for SS, Tubes, DAC ?
What do they bring and what they don't in power regulation, please ?


Thanks in advance for your inputs. I'm in particular interrested for tubes PS to swap the rectifier tube topology and also lower PS like ones for DAC devices 😕

 

[egellings]

I know there is a Static Induction Transistor (SIT), but am not aware of a diode using that technology. Not sure how it would.

 

[diyiggy]

Uh, I made a spelling error mixing with the famous Sony transistors.😱

Here a datasheet about what I'm talking : SIC diodes !



I know nowadays some use also IC chip for that purpose as well !


WHere does it matter ? Can we hear it, or is it juist for measurement gears ?

 

[diyiggy]

A little up.


So no particular to use those Schottky SIC diodes over non SIC ?

 

[Greg Stewart]

Cree SiC diodes were the rage back in the early 2000s. I built up my Bottlehead Seduction phono stage using them in 2003:

Audio Asylum Thread Printer

I thought it sounded good, though I never experimented with alternatives then.

Nowadays I'd spend weeks comparing... some rabbit holes I try to avoid if I can!

Greg in Mississippi

 

[diyiggy]

Thanks Greg.

I am a little late. I wondered if usefull...but with for instance Vishay SYB 27 for rectifiers we are soft and veryyyy fast with 15 nano seconds....

 

[Greg Stewart]

My experience is that you just have to try them and compare. I've not heard any strong correlation between measured specs and SQ in the higher-quality fast / soft-recovery diodes.

My 2 cents.

Greg in Mississippi

 

[diyiggy]

fair advice... I even saw some do not use parralel film cap filtering for them, saying the cap is a direct high pass for high frequency noise ! Better to use a serie output resistor on each raiul before the main smoothing cap, well OT !


Ok thanks, will use more classic and better for the wallet Schottky and very fast diodes.

 

[TonyTecson]

i used 10Amp flat in line bridge rectifiers on my tube amps that drew not more than 300mA of load currents....ordinary silicon rectifiers only please....leave the high speed stuff to smps where they can be of very good use...

 

[diyiggy]

Oh, I see !



Many thanks Tony ! Cause tube apps is what I have mainly in mind.... I found a nice **E188CC**, I don't want to waste that nice tube !

 

[Mark Tillotson]

silicon carbide (SiC) is a wide bandgap semiconductor, and outperforms Si in many areas, but only recently has it been possible to create sufficiently pure crystals of it for use in electronics. Its coming of age now.

 

[diyiggy]

Not sure if I understand. You mean it's good but there is better (sorry I'm lost in translation)



Is there an agreement about its use, please, in rectifiers ?


Good for SolidState, Bad for tubes rectifiers and further soft starting layout ?

 

[egellings]

Silicon carbide (SiC) diodes have a much larger forward drop than standard Si diodes do. That could be an issue in low voltage supplies not designed to take that into account. What they get you is nearly no reverse recovery time, and for 50/60Hz, that's a nothingburger; i.e. simply not needed. In HF switchmode settings, however, it matters.

 

[diyiggy]

Thank you for the further input. Clearer on how to use it or not.

 

[trobbins]

diyiggy - did you try and locate your likely applications on Fig 7 of your post #3 link ?

If you had purchased some SiC diodes and wanted to use them then it is in your interests to do some basic pre-design on how to use them - the end of section 2 of link goes a bit in to that for valve amps (ss amps would need more assessment on peak diode current consequences.
https://dalmura.com.au/static/Power%20supply%20issues%20for%20tube%20amps.pdf

 

[diyiggy]

Hi trobbins,

No, I just wondered, but indeed I plan a powersupply for a small 7803 tube.
Many thanks for the link