What to do with extrememely low Vf diodes?

[hymenoptera]

What are some uses for diodes with crazy-low forward voltage drops?

I ordered 100 x 1n4148, and instead got 100 x BAT85. Forward drop measures 198mV @ 1mA. Are there any circuits that call for especially low Vf clipping diodes? Are these too delicate to be used as circuit protection? Datasheet says they're good for 200mA.

Do I return them? Or did I hit the jackpot? 

[MrStab]

more-efficient voltage multipliers come to mind, a less-serious suggestion would be clipping diodes for a low-voltage overdrive!

[mth5044]

You can use them in not low voltage over drives as well

[alr300]

Couldn't you stack them in series as clippers?

[MrStab]

they'd probably allow for quite a stark difference between halves of an asymmetrical clipping setup at 9V, but personally i wouldn't use em on their own. at least not in the typical YATS. but then, depends what you're going for.

[merlinb]

You can use them as passive clippers inside the guitar itself, for some mild, battery-free overdrive.

[antonis]

Forward drop measures 198mV @ 1mA. Are these too delicate to be used as circuit protection? Datasheet says they're good for 200mA.

I think they are good enough for most of "simple" circuits...
(many of them have current consumption less than 200mA)

For more current you can wire 2 or more of them in parallel but with a small resistor in series with each diode for equal current sharing - these resistors can also serve as "R" in RC power filter..

P.S.
I'll suggest you to measure the actual voltage drop at high limit current, if it isn't clearly stated on datasheet..

[anotherjim]

They generally aren't liked used in signal paths. Low Vf yes, but also very fast switching. Heard as harshness. I've seen an article that shows a little series R and maybe some filtering changes can equal other diode types as clippers, but while the usual diodes for those circuits are available - what's the point? Some designs do use Schottky clippers as switch-able alternatives to other types and sometimes using only one against another type to create asymmetry.

In signal rectifiers feeding envelope detectors (compressors and such), they could be used without worry. The lower Vf helps in these (and some schemes specify Germanium diodes for that reason), but the improvement isn't as noticeable as you might hope.

[hymenoptera]

All great info! Thanks, all!

What about in a ring mod? The style where it's transformer > bridge rectifier > transformer? I know highly-matched low-Vf germaniums are called for, but these BAT85's would also seem to fit the bill nicely. Thinking about buying the Synthrotek ring mod PCB and a couple of transformers from Mouser, maybe.

[anotherjim]

Ring Mod'? Have at it Sir!

[hymenoptera]

Okay, I think I'm going to do something similar, but different.

I'm going to try a couple of these in a Green Ringer. Should be perfect for that circuit!