just a simple dumb question. 5 hours ago i just getting a psu that really "new" from my friend. i think those are used just for about 2-3 months before failed. It hasn't even a hair of dust insidely !! so i just open the case and looking for the culprits, smelling and looking round and i notices one diode has burned on the board. so i checks it in circuit. it has low reading resistance both forward and reverse. desoldering it and see the diode is 1n5819. i have a 1n4007 on my box same amperege as those diode, trying to replace it and get a good result. but the question, it is dangerous for my cpu if i using those 1n4007 instead 1n5819 in the psu to powering my psu? also it could long last? yes i have download the datasheet already, but i didn't know exactly, i think the expert one on repairing usually know about universal replacement parts. any short answer appreciated. thank you
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1n5819 rectifier replace with 1n4007 rectifier??
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
1N5819 is a fast, low loss, schottky rectifier.
1N4007 Is a slow, high loss, silicon rectifier.
No, you cannot. The 1N4007 will likely last a few minutes before failure, probably less.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
Originally posted by tom66 View Post1N5819 is a fast, low loss, schottky rectifier.
1N4007 Is a slow, high loss, silicon rectifier.
No, you cannot. The 1N4007 will likely last a few minutes before failure, probably less.
thank you for your kind answer"There is no shortcut to be successful. No pain, no gain."
Best Regards
Rudi
Thank You
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
A 1N5819 is a 1A, 40V Schottky rectifier; its V(f) at 1A is .6V, and it is very fast. A 1N4007 is a 1A, 1000V standard recovery rectifier; its V(f) at 1A is 1V, and its reverse recovery time is ~920nS. If the circuit in the P/S requires either the lower forward drop or the very fast reverse recovery time, a 1N4007 will fail pretty quickly, though it may take more than a few minutes. I strongly recommend that you replace that 1N4007 with a 1A-3A, 40V-60V Schottky rectifier, as I don't think the circuit designer would specify a Schottky rectifier without a reason.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
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To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
Originally posted by PeteS in CA View PostA 1N5819 is a 1A, 40V Schottky rectifier; its V(f) at 1A is .6V, and it is very fast. A 1N4007 is a 1A, 1000V standard recovery rectifier; its V(f) at 1A is 1V, and its reverse recovery time is ~920nS. If the circuit in the P/S requires either the lower forward drop or the very fast reverse recovery time, a 1N4007 will fail pretty quickly, though it may take more than a few minutes. I strongly recommend that you replace that 1N4007 with a 1A-3A, 40V-60V Schottky rectifier, as I don't think the circuit designer would specify a Schottky rectifier without a reason."There is no shortcut to be successful. No pain, no gain."
Best Regards
Rudi
Thank You
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
I have seen some switching PSUs use a 1N4007 in the secondary to feed the SMPS chip. Bad, but surprised it worked. I guess the low current requirements may let it work (milliamperes) but I was surprised that the reverse recovery time was fast enough.
If you had an UF4007 instead, these probably are better for replacing a 1N5819, but even these are a terrible replacement due to the Vf drop being higher.
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
I'm guessing a UF4007 is a 1A, 1000V ultra-fast - 25-50nS reverse recovery time. Fast, but probably a 1.2V-1.5V V(f) at 1A.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
Originally posted by eccerr0r View PostI have seen some switching PSUs use a 1N4007 in the secondary to feed the SMPS chip. Bad, but surprised it worked. I guess the low current requirements may let it work (milliamperes) but I was surprised that the reverse recovery time was fast enough.
If you had an UF4007 instead, these probably are better for replacing a 1N5819, but even these are a terrible replacement due to the Vf drop being higher.Originally posted by PeteS in CA View PostI'm guessing a UF4007 is a 1A, 1000V ultra-fast - 25-50nS reverse recovery time. Fast, but probably a 1.2V-1.5V V(f) at 1A."There is no shortcut to be successful. No pain, no gain."
Best Regards
Rudi
Thank You
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
Yes it's less efficient and if the 1N5819 failed in a short time then the UF4007 will faster but at least it will work for a quick test.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
A standard recovery rectifier (e.g. 1N4007) has a 50%-70% higher v(f) than a schottky (i.e. higher loss when conducting); it also switches off slower, so it also has higher losses when switching. The latter losses become increasingly significant as the frequency being switched increases (i.e. not significant at 50Hz or 60Hz, but critical at SMPS frequencies).
An ultrafast has a V(f) ~20% higher than a standard recovery rectifier, and 80%-100% higher than a schottky. So I think an ultrafast would probably last longer than a standard recovery rectifier, but overheating is certainly possible, and other things might suffer (e.g. efficiency, cross-regulation, low-line regulation).PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************
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Re: 1n5819 rectifier replace with 1n4007 rectifier??
wow. i dont even hope could get any answer for this dumb question. smps frequency using a high frequency maybe around kHz-MHz as i know if not wrong, so it must to be consider when using the rectifier (different with linear psu that almost same as mains frequency) and guess what? i dont have good enough knowledge about the rights replacement.haha. btw i have fixed her and her running well now, thank you for all of kind (especially the friend those kindly give me)
i had learn much from this forum.Last edited by senz_90; 10-22-2013, 02:17 PM."There is no shortcut to be successful. No pain, no gain."
Best Regards
Rudi
Thank You
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