Smallbear's new Univibe photocells and some other fun stuff

[midwayfair]

http://www.smallbearelec.com/servlet/Detail?no=1580

Just in case anyone missed it or is looking for a real in-spec part for their Harbinger. Maybe a year or two Smallbear noticed (and got complaints about) the Silonex 7532 photocells, which no longer had the super high dark resistance they used to have.

Granted it's 200M after 5 seconds, but it should easily get to several megs on a medium speed in a tremolo or something.

If I get some, I'll also end up testing them in the Cardinal, which might make things a little cheaper for folks balking at $7-$10 each for the 5C1s.

Oh, and he also got some interesting germanium diodes:
-1N100s in if you're building a replica Orange Squeezer, though I'd still recommend a decent Schottky there.
-A couple "transistor" style Ge diode packages with super low Fv

[Govmnt_Lacky]

Saw those yesterday....

Light resistance?? Recommended wavelength??

[LaceSensor]

interesting, Be keen to hear your thoughts on them

[madbean]

Got some already on the way I am excited to give those a go.

[cooder]

Awesome, thanks for the heads up and good to know... makes me wonder if my great sounding Harbinger could sound even sweeter with these...?!?

[midwayfair]

Steve sent me the datasheet link by e-mail:
https://www.smallbearelec.com/Library/Datasheets/UnivibePhotocell.pdf

Same on resistance and switching time as the 7530, just exponentially higher dark resistance. So the switching time isn't the fastest (that probably still belongs to the VTL5C1), but their specs are otherwise pretty much perfect for almost everything, not just the Univibe.

[Govmnt_Lacky]

Hmmmmmmmm....

Spectral peak of 615nm puts it in between the Green and Red spectrums for maximum efficiency.

Looks like it will take some experimenting with LED color to find just the right balance.

[jubal81]

Hmmmmmmmm....

Spectral peak of 615nm puts it in between the Green and Red spectrums for maximum efficiency.

Looks like it will take some experimenting with LED color to find just the right balance.

I always wondered about using RGB leds to dial in the spectrum ...

[midwayfair]

Hmmmmmmmm....

Spectral peak of 615nm puts it in between the Green and Red spectrums for maximum efficiency.

Looks like it will take some experimenting with LED color to find just the right balance.

Orange is the closest.

I suspect brightness trumps wavelength even when there's a huge drop in efficiency. A blue LED is many, many times brighter than a red LED. For instance, when I was futzing around with every photocell I could find for the blue warbler, I measured a bunch with different LEDs on them, and the NSL-7530 was driven down to a few K (yes, lower than the datasheet) with a blue light but was a little higher than that with a red light.