how to make a Led/LDR like a VTL5C1?

[morelius21]

Hello!

I want a build the double flush but i have a question. I want to make the Vactrol (VTL5C1) but I don't know what type of LED & ldr to choose. I searched in topics but i didn't find.

Thanks for your answers,

MOrelius21

[Haberdasher]

Here, have a look at madbean's build.  I think he said he used a red 10mm clear led along with a photocell out of a radio shack assortment bag.  It looks like they're just each soldered in & bent over at 90's towards each other so they meet face-to-face.  Some people enclose that in heat shrink but Brian didn't seem to think it was necessary once it was inside the enclosure.

There is also some info in the build doc on the projects page and there may be one or two more threads on completed projects in the Builds room on this forum.

I haven't built it yet, so that's all I got.

[morelius21]

Hello,

I have looked at madbean's build and I understand the construccion. The problem is that I find a lot of diferent  resistor values of the photocells. When i use led red (10mm) what value of photocell should I choose?

Before i didn't explain correct my question!!!Sorry   


-thanks

[Haberdasher]

...maybe I should wait and let someone who has built the pedal take this, but I do remember reading that the value of the photo-resistor is not critical in a trem the way it would be in a vibe.  I think you can just grab one roughly the same diameter as the LED you end up using and give it a whirl.  If you're worried about it, I guess you could socket that side & try different pieces.  Once you're satisfied, solder down one one of the legs so it stays put.

[morelius21]

OK, thanks, you have given me a good solution, I wait for another answer if not i will try diferent photocells.

MOrelius

[Haberdasher]

ok, good luck.  I'll be in the same boat soon, so let me know what worked for you. 

[stecykmi]

I've not built this project, but I think I remember people saying the values of the LDR were not critical.

[nzCdog]

I built this pedal using a small cheap photocell from futurlec and a standard 5mm clear red LED.
Popped a bit of heatshrink on to join them together, nice and compact and works a treat... I must say it is one of the most lush sounding tremolos I've played.  Me likey!

FYI the LDR/Photocell I used had these specs:
Rating: Vp - 150, mW - 100
Resistance: Light - 10 kohm, Dark - 100 kohm
Dimensions: 5mm Wide, 4mm High, 2mm Thickness

[morelius21]

Hey!

Thanks, now i have a lot of information. I will make the Vactrol and i will tell you the results.

MOrelius21

[madbean]

You could always look up the datasheet for the VTL5C1 and get the nominal dark/light resistance. There's a lot of interesting info in the datasheet, and it covers just about all the Vactrols they make.

I only used the 10mm cause it looked cool...even a 3mm would probably work. And, I pulled my photocell out of the bag without bothering to check any spec on it. I did this on purpose to see if the result was good without worrying about the specs. It was