Anyone used Phillips BYM26C diodes before? Specs look really good to me (but what do I know?) At 30nS, they appear to be 40% faster than MUR860, AND they are soft recovery too! I know they are only rated @ 2.3 A, but I don't think that will be a problem for me, as I am thinking of using them for a bridge in an Aikido preamp PSU. The reason I am asking about this particular one is that it shows up in a local supplier's catalogue.
I see they (Phillips) call this a fast soft recovery controlled avalanche rectifier. Quite a mouthful! I don't understand exactly what that means, so I hope it doesn't mean they are unsuitable for my needs.
I see they (Phillips) call this a fast soft recovery controlled avalanche rectifier. Quite a mouthful! I don't understand exactly what that means, so I hope it doesn't mean they are unsuitable for my needs.
What's the difference between ultrafast diode (like MUR820) and ultrafast soft recovery (like FFPF06U20S)? Fairchild one is "soft recovery", what the difference with other ultrafast rectifiers.
Is schottky still better than "ultrafast soft-recovery"? I can get MUR820, FFPF06U20S and 90V schottky here (enough for +/-35V rectification, I guess), which one is better for audio gear rectifier?
Is schottky still better than "ultrafast soft-recovery"? I can get MUR820, FFPF06U20S and 90V schottky here (enough for +/-35V rectification, I guess), which one is better for audio gear rectifier?
I want something self healing, so a small metallized film of no bigger than 0.1uF works fine. IMO, a full blown snubber circuit is overkill. Hint- find a small AM radio and tune it to between stations. Hold the antenna near your operating bridge. Don't short it out! If you hear an increase in noise near the bridge (or any other part of your audio equipment), it's time for some bypassing. There's probably a difference in the amount and frequency of junk generated by various types of diodes, but I don't know the specifics. I do find faster is better than slower, even on 60hz circuits.
A full blown snubber circuit? Just 1 resistor added to your film cap. I will always go that extra inch, no matter what diodes I am using.
Actually, I started out using good old 1n4007's, even in bridges for 15v PSU's. Then someone said try MUR 860 - everybody says they are so good , so fast etc. Well, my experience was that the when both were snubbed, the 1n4007's seemed to sound better (at least to my ears.) Maybe the fast switching creates a hectic spray of higher harmonics that are more difficult to get rid of? Anyone had similar experience?
Actually, I started out using good old 1n4007's, even in bridges for 15v PSU's. Then someone said try MUR 860 - everybody says they are so good , so fast etc. Well, my experience was that the when both were snubbed, the 1n4007's seemed to sound better (at least to my ears.) Maybe the fast switching creates a hectic spray of higher harmonics that are more difficult to get rid of? Anyone had similar experience?
Hi Lumanauw,
I don't have enough experience to answer your question with certainty. From what I have read, soft recovery may be even more advantageous than high speed, but why not get both properties in one diode? As for comparisons to Schottky, I think there are probably a lot of people who would like to know the answer to that one! Wouldn't you like to be a "test pilot" and give us all a report back on that comparison?
I don't have enough experience to answer your question with certainty. From what I have read, soft recovery may be even more advantageous than high speed, but why not get both properties in one diode? As for comparisons to Schottky, I think there are probably a lot of people who would like to know the answer to that one! Wouldn't you like to be a "test pilot" and give us all a report back on that comparison?
Do the radio trick. If the diodes are generating anything, it will probably be at a frequency where the radio can easily pick it up, and that's a lot more sensitive than a scope- microvolts instead of millivolts. Then, if you're like me, you'll run about the house checking for RF from everything else. My humidifier turned out to be a terrible generator until I added an LC filter to the motor speed control. A snubber can be more than a single resistor, but in this case I don't know if even a resistor is needed. You should probably just ignore the next part, but IMHO if you can hear the effect of this sort of ps mod, other than killing off RF, which I believe can be audible, there is something fundamentally wrong with either the circuitry or the grounding scheme. The type of cap used on the diodes, and even the type of diodes themselves, shouldn't be audible. Not even to bats or dogs, who hear way better than we do. I wouldn't be quite so negative, but I just did some tests of various supply changes and found their audibility is mostly self created illusion. Anyway, I'll go for the self healing metallized part, because it could save the rest of the power supply in the event of failure. Admittedly diodes fail too, but why add to the risk? If you were working on the input side of the fuse, say for a line filter, nothing else would be acceptable. In this case you have a bit more freedom.
O.K., so now I have to go buy an AM radio and start looking for 400v Schottky's?!
Seriously though, thanks for the info guys.
When I use the bym26C's, I will report back if anyone is interested enough to hear my take on them.
As for snubber caps, I always use seriously overrated caps (1000v or more). If they fail, then I have to believe the hi-fi gods are after me and it is time to start changing my ways.
Seriously though, thanks for the info guys.
When I use the bym26C's, I will report back if anyone is interested enough to hear my take on them.
As for snubber caps, I always use seriously overrated caps (1000v or more). If they fail, then I have to believe the hi-fi gods are after me and it is time to start changing my ways.
The hi-fi gods are fickle and you have to sacrifice some semiconductors every now and then, lest a horrible fate befall your system. Though I've been able to hold off disaster for quite a long time, they only tease me with almost-good-enough sound, but never allow me long term satisfaction.
And yes, you do have to find an AM radio. Surely you can get some cheap Walkman-like thing, or an old rectangular transistor radio. It will give you more bang for the buck than any other piece of HF test equipment. We talk a lot about RF, but wouldn't it be nice to know if there's really something there?
And yes, you do have to find an AM radio. Surely you can get some cheap Walkman-like thing, or an old rectangular transistor radio. It will give you more bang for the buck than any other piece of HF test equipment. We talk a lot about RF, but wouldn't it be nice to know if there's really something there?
I have specialized equipment to satisfy the God of Smoke and keep the Prince of Darkness satisfiedConrad Hoffman said:
This beast eats mosfets one tube at a time and full bag of electrolytics
http://www.ee.oulu.fi/~tech/kart/6_8_07/IMG_3857.jpg
http://www.ee.oulu.fi/~tech/kart/6_8_07/IMG_3859.jpg
http://www.ee.oulu.fi/~masaj/Lipasto_takeaway/P1070687.JPG
Once they pop you cant stop
(when one of the 24 parallei fets dies the rest of the story is _very_ short with 1800A)BTW: Conrad, that one has pretty low supply impedance, apprx 0.25mOhm, and no plastic caps
Hi, TVI,
Thanks for the link
But this murdiodes.pdf article seems not obtainable now. http://www.irf.com/technical-info/whitepaper/murdiodes.pdf
Do you still have a copy?
Thanks for the link
But this murdiodes.pdf article seems not obtainable now. http://www.irf.com/technical-info/whitepaper/murdiodes.pdf
Do you still have a copy?
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