What are good diodes to get? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: May 27, 2019, 07:27:41 pm
content: What are the most recommended diodes to have on hand ? I'm nearly out of general purpose rectifiers, and signal diodes, and zeners, and LEDs too.And how good/bad are cheap ebay diodes vs buying brand name, diodes ?I have lots of 1N60 Germanium diodes, some varactor diodes.What all precision diodes are there ?my short list is some1N41481N400x1N54xxhigher wattage zeners than the 1/8 or 1/4W ones I have, but they are hard to find on ebay and expensiveWhat are some high current rectifiers for mains powered projects/repairsI barely have any fast switching diodes, for SMPS.Whats are some state of the art diodes ?? And RF diodes ?

author: bd139
author_rank: Super Contributor
timestamp: May 27, 2019, 07:52:16 pm
content: 1n4148 for 99% of stuff. 1n5711 for RF bits, mostly power detection for me. 1N4007 for low current rectifierEverything else I buy when I need it. There's not a lot that can't be done with the above that isn't expensive to keep in stock.

author: mariush
author_rank: Super Contributor
timestamp: May 27, 2019, 07:55:49 pm
content: Go to a store like Digikey and sort by quantity in stock - chances are whatever's stocked in bigger quantity is more popular. ex seehttps://www.digikey.com/short/p4dwnzLook into some fast/ultrafast rectifiers (UF**), schottky diodes, maybe stock some bridge rectifiers in DIP package or SIP (gbu family and others) instead of using 4 diodes to rectify ac voltagelook into max current and also forward voltage drop at some current... ex. 1n4007 may be good for up to 1A as long as you're fine with 0.8v..1v voltage drop at even 200mA but maybe you'll also want a 1A diode that has only 0.3..0.5v drop at 100-300mAMay want to have some 3A..5A diodes in stock even if you're gonna use them in 0.5A..1A circuits, simply because at 0.5A..1A the voltage drop will be very small and the diode's properties won't change as much with heat (bigger package, thermal mass etc)

author: bob91343
author_rank: Super Contributor
timestamp: May 27, 2019, 09:28:57 pm
content: I have thousands of 1N4148s so I will never have to buy any. I have a large stock of 1N4007s so those are good.Anything else, well I try to get germanium diodes like 1N270 to keep handy. And zener diodes are a different issue.From salvaging parts of obsolete or broken stuff I have amassed lots of LEDs, and rectifiers of the two and three or four in a package, some capable of several amperes. There are some high voltage diodes too, many with high current ratings.For varicaps I have found that ordinary diodes will behave well. I measure on my bridge while adjusting reverse bias. For temperature compensation of power amplifiers, again ordinary diodes do well, especially 1N4148. Sometimes I need a few in series and of course attached to the heat sink.

author: David Hess
author_rank: Super Contributor
timestamp: May 28, 2019, 12:15:33 am
content: These days I tend to use fast recovery rectifiers in place of standard recovery parts like the ubiquitous 1N4001 series simply so that I can stock fewer parts. I also tend to only buy the highest voltage part of a given series for the same reason.So for instance the 200 nanosecond 1N4937 replaces the 1N4001 through 1N4005 standard recovery rectifiers.

author: lordvader88
author_rank: Frequent Contributor
timestamp: May 28, 2019, 03:33:25 am
content: For typical usage, is there any reason to buy rectifiers that have lower blocking rating lower like the 100V 1n4001, if the price is the same would u just buy 1kV 1n4007 ?IDK any diode or transistor model that add internal capacitance or inductance. Over the years I've collected lots of diodes from CRT TVs, I guess I'll need them to make a CRT TV.Lately I made a little 17VAC Octopus tester , now I'm working on a curve tracer circuit, finally I made a way to test zener, but now to sort them out

author: digsys
author_rank: Unknown
timestamp: May 28, 2019, 04:18:06 am
content: Quote from: lordvader88There's be a bees dick in it - capacitance, leakage, IR loss etc but nothing that would concern any power app or general use. In those cases, you'd be lookingfor something a lot more specialized anyway. 1N4007 is most peoples "standard". Plus the 1N5404 or similar for 3A

author: David Hess
author_rank: Super Contributor
timestamp: May 28, 2019, 04:32:02 am
content: Quote from: lordvader88 on May 28, 2019, 03:33:25 amThe higher voltage diodes may have slightly different specifications in other respects. For instance the 600 volt MUR160 is 50 nanoseconds and 27 picofarads but the 900 volt MUR190 is 75 nanoseconds and 15 picofarads.Higher voltage parts usually have higher forward voltage drops but not always.All of the members of the 1N4937 series are the same except for voltage but the similar 1N4948 series has longer recovery times for higher voltage parts.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 28, 2019, 04:43:50 am
content: General purpose switching diode, PN: 1N914/1N4148 (THT), 1N4148W (SOT-123)Signal schottky diode: BAT85 (THT), BAT54H (SOT-123), BAT54S (SOT-23) (or other variants, -C and -A are common cathode/anode, S is series, etc.)General purpose rectifier: UF4007 (THT), ES1J (SMA), don't bother with slow (1N400x), who caresSchottky rectifier: B340 (SMA), etc.Also UF540x for higher current, or anything MUR (ultrafast rectifier), MBR ( barrier rectifier), B or SB, PMEG, etc.Zener: 1N5231B (5.1V 500mW), 5242 (12V), etc. 47xx is 1W series, etc.TVS: P6KExx(C)A, 1.5KExx(C)A, SMAJxx(C)A, etc.Probably if you need something more special than these, just buy them specific for the project.Tim

author: Brumby
author_rank: Unknown
timestamp: May 28, 2019, 05:15:17 am
content: Quote from: bd139 on May 27, 2019, 07:52:16 pmI'm the same, but I have a fistful of 1N5404 (3A) left over from a project that have been useful every now and then.

author: bd139
author_rank: Super Contributor
timestamp: May 28, 2019, 07:21:04 am
content: I probably have some 54xx as well. I’ll probably just buy more rather than try and find them. Although up there I tend to go for Vishay SB series diodes.A couple of things that are good about the 1N4007 which is why I keep them around versus an UF diode:1. They actually make a fairly reasonable and cheap PIN diode.2. They are less noisy than UF400x.I have some super fast diodes as well which were used to fix a Tek power supply (STTH2R06)