schottky vs. soft/fast recovery diodes - Page 2 - diyAudio
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Old 21st February 2010, 08:21 PM   #11
Telstar is offline Telstar  Italy
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This thread answers some of my questions. I put it up cause diodes are often neglected
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Old 21st February 2010, 10:17 PM   #12
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I've found it effective (with small transformers) to put an RC snubber on the transformer secondary, tuned to minimize ringing. Similarly, smallish and very low ESR bypass caps on each rectifier is a common practice, although I think a tuned RC there ought to be more effective at damping out the ringing, in combination with a Schottky or soft recovery device.

Even with Schottky or soft recovery devices, there is still inductive ringing; an RC snubber can deal directly with this problem, small as it may be.
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Old 22nd February 2010, 04:18 AM   #13
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Has anybody used MBR40250 in their power amps?
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Old 22nd February 2010, 11:50 AM   #14
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BTW, the CREE 600V/4A cost now 3,66.
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Old 6th October 2010, 02:43 AM   #15
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Default There...

are a lot of Shottky options available these days, especially for source component power supplies. I have a question though:

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Schottky diodes:

+ Low forward voltage
+ Fast recovery time
- Not available in ratings higher than about 60V
- high leakage current


What are the specific drawbacks of high leakage current? Thanks to anyone who can explain this to me.
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Old 6th October 2010, 02:50 AM   #16
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As a bridge rectifier, depends how high the leakage current. Not much disadvantage at all if its a few milliamps - the diode runs slightly warmer, slightly less efficient power supply.
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Old 7th October 2010, 01:03 PM   #17
Telstar is offline Telstar  Italy
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Quote:
Originally Posted by barrows View Post
- Not available in ratings higher than about 60V
False.
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Old 7th October 2010, 02:38 PM   #18
housing is offline housing  Hong Kong
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Quote:
Originally Posted by barrows View Post
are a lot of Shottky options available these days, especially for source component power supplies. I have a question though:

"
Join Date: Apr 2004
Location: Brisbane

Click the image to open in full size.

Schottky diodes:

+ Low forward voltage
+ Fast recovery time
- Not available in ratings higher than about 60V
- high leakage current


What are the specific drawbacks of high leakage current? Thanks to anyone who can explain this to me.
All false. Please refer to the datasheets of the latest silicon carbide schottky diodes.

Forward voltage more or less the same as FRED.
Zero recovery time.
Voltage rating higher than 1000V.
Very minimal leakage current.
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Old 7th October 2010, 03:44 PM   #19
housing is offline housing  Hong Kong
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I better rephrase my above reply as follows since I can't edit it now.

All false with the latest silicon carbide schottky diodes. Please refer to their datasheets such as:
http://www.cree.com/products/pdf/C2D10120.pdf

Forward voltage more or less the same as FRED.
Zero recovery time.
Voltage rating higher than 1000V.
Very minimal leakage current.

But I don't know whether they have any sonic benefit in audio application.
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Old 10th October 2010, 06:34 PM   #20
goody75 is offline goody75  United States
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Quote:
Originally Posted by Damon Hill View Post
I've found it effective (with small transformers) to put an RC snubber on the transformer secondary, tuned to minimize ringing. Similarly, smallish and very low ESR bypass caps on each rectifier is a common practice, although I think a tuned RC there ought to be more effective at damping out the ringing, in combination with a Schottky or soft recovery device.

I apologize for my ignorance but could you please be more specific about the RC snubber for the transformer secondary. I guess I am particularly interested about values and placement (e.g. between the negative and the 0V?).

Thanks.
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