Any experiences bypassing UF4007 with .01uF cap?

[mtl777]

noise should not matter b/c the 22 ohms impedance is so small here, so either or
If I was doing snubber studies and plots of ringing in switching test circuits I might prefer carbon. Can you buy decent carbon resistors in 1/8W ?

No. DigiKey has only 1/4W for 22 Ohms carbon comp. I guess 1/4W is fine, right? And the nearby store (which saves me shipping cost) has only metal films. Metal films will also be fine?

 

[infinia]

Yea I don't think its really a huge deal here but all things being equal i think physically smaller parts are better RF wise.

 

[mtl777]

Yea I don't think its really a huge deal here but all things being equal i think physically smaller parts are better RF wise.

OK, thanks a lot! 🙂

 

[mtl777]

added snubbers and HF bypass
see attached 0.01uF ceramic 100V , 22R 1/8W10%, & X7R ceramic 0.1uF bypass

As I was going through my things, I found some 0.01uF 100V Wima FKP2 caps. Can I use this instead of 0.01uF ceramic? Will FKP2 be even better due to it being polypropylene foil or is ceramic the preferred type for RC snubbers?

If FKP2 is not good for this, how about polyester? I also found some 0.01uF 100V polyesters that are like chicklets and are smaller than FKP2.

 

[infinia]

go for smaller lead pitch for plastics, I like ceramic for RF stuff and supply bypassing. But you can use what you have.

 

[mtl777]

Thanks! 🙂

I have one more question. In the Delta 1010 PSU schematic, C22 and C60 are 2200uF 25V. Would it also be good to bypass each of them with a 0.1uF 25V X7R ceramic?

 

[DreadPirate]

I have a question on the use of UF4007. I believe these are claimed as "better" due to their fast response? If so, why not use UF4004 that is faster and still 400V which is more than adequate? Your getting a 30% quicker response (50 vs 75) and not giving anything up, since they are also high voltage. Or is there some other reason to go with 1000V?

http://www.fairchildsemi.com/ds/UF/UF4005.pdf

 

[mtl777]

I have a question on the use of UF4007. I believe these are claimed as "better" due to their fast response? If so, why not use UF4004 that is faster and still 400V which is more than adequate? Your getting a 30% quicker response (50 vs 75) and not giving anything up, since they are also high voltage. Or is there some other reason to go with 1000V?

http://www.fairchildsemi.com/ds/UF/UF4005.pdf

Well, my only reason is because the UF4007 is what I have at hand right now. 🙂 But yeah, any of the UF4001 to UF4004 is faster, though I'm not sure about "better" as I'm not an expert. Let's leave that question to the gurus on this forum. Which brings me to this question:

What parameters or other info from the data sheet should be considered when comparing and choosing diodes for audio gear? Like, is faster reverse recovery time better? Or how about "soft recovery" -- how is it quantified in the data sheet?