Hey there!

I'm looking at a circuit using a VTL5C4/2 , I've never used such thing

So from the datasheet while for a normal photoresistor we vary the resistance of that single resistor, here is like having a potentiometer?

I mean the resistance between pin 3 and 5 is always the same?
Or is like modulating 2 resistors that will have the same resistance anywhere on the curve?

 

What are you planning to use it for?

It is not like a pontentiometer because what would be the wiper on the pot is fixed and never moves, and the two LDRs vary in resistance with the light from the LED which means the resistance on 3 and 5 varies in proportion. It acts as a voltage divider which would be beneficial in some circuits.

 

Is there really a pin 4? There is in the diagram but not in the photo.

And don’t think of designing it into anything commercial. It contains cadmium, so is illegal under RoHS regulations.

(although it does contain rather less cadmium than there is arsenic in a red LED)

 

Is there really a pin 4? There is in the diagram but not in the photo.

And don’t think of designing it into anything commercial. It contains cadmium, so is illegal under RoHS regulations.

(although it does contain rather less cadmium than there is arsenic in a red LED)

Pictured and mentioned in this. There are some application notes that mention the matching of the two elements but unfortunately no specific circuit examples. They mention that it can be “used as a voltage divider” and that’s as far as they go.

 

Guitar envelope filter, here you go

 

Is there really a pin 4? There is in the diagram but not in the photo.

And don’t think of designing it into anything commercial. It contains cadmium, so is illegal under RoHS regulations.

(although it does contain rather less cadmium than there is arsenic in a red LED)

The picture is of the single one

Here it is in all it's beauty



There's also written "RoHS complliant" on their page

https://xvive.com/audio/product/vtl5c4-2/

 

I once researched the use of cadmium, particularly with Cd:S cells in mind and apparently small amounts of it are ok. Just don't lick the photoresistor

 

There's also written "RoHS complliant" on their page

https://xvive.com/audio/product/vtl5c4-2/

They would say that. Unfortunately, it's a big fib.
Cadmium Sulphide optocouplers were granted an exemption to the RoHS regulations, (Annex III, exemption 40) but it expired at the end of 2013.

 

Thank you for this. It had so far been elusive.