Making a VTL5C3 optocoupler

Ok, you got your soldering iron and nothing is going to hold you back, but you have no clue where to start or what to build. There were others before you with the same questions... read them first.
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Mrutg
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Post by Mrutg »

As far as i am concerned - it's a diode with photoresistor. I have seen people making them from diode and photoresistor elements.
But what should i take into consideration when chosing them for a optocoupler - ?
Will standard (on off red light diode) be ok? How to chose the photoresistor basing on On resitance and OFF resistance of an optocoupler datasheet?
This is for the McMeat clone.

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Nocentelli
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Post by Nocentelli »

Meatball/McMeat is not too picky about optocoupler used since the intensity control has an influence on the responce as well. It's more important that the two photoresistors/LDRs used for the two optocouplers have similar specs: I'll look at home tonight for the ones I used.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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Mrutg
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Post by Mrutg »

Looking foreward for your reply!
:)

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Post by Nocentelli »

Ok. I found the packaging they came in but it doesn't have the specs on. They are 5mm from Tayda, and I measured them before I put them in, and I recall they were around 1M in darkness and just under 1k fully illuminated. I'll just re-iterate that a) the specs aren't that critical since both the sensitivity pot and the intensity pot have a major influence on the sweep in conjunction with the response of the LDR, b) it's more important that whatever the spec, the two LDRs you use have SIMILAR specs for maximum filtering effect, and also c) when you actually measure them, they are not always that close to the specs quoted.

I used green standard 5mm LEDs.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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