Easyvibe, easy question

[Bucksears]

(....but I still don't know the answer)

On the Easyvibe, is there a particular direction the cathodes should be facing with regards to the LDR package soldered into the board? I couldn't see anything on the layout, so i thought I'd ask before assuming it doesn't matter.

Thanks!
- Buck

[petemoore]

  LDR's like resistors, are non directional, or, have no polarity.

[Bucksears]

Ok, thanks!
I have the photocells and LEDs, I just didn't know if (after you seal the two together) the LED's cathode needs to be facing one way or the other in order for it to work.
I finished etching/drilling the PCB and just need to populate the board next.

Thanks again,
- Buck

[Bucksears]

Pete,
When I built the Craig Anderton Tremolo, it used a CLM6000 Opto-Isolator, which needed to be oriented correctly with the cathode on a particular side.
Is there any similarity to that and using the LED/photocell combo in the Easyvibe?

Thanks,
- Buck

[petemoore]

  The LED should have...er...LED's 'plain' are marked and have polarity just like the LED in your opto...
  This can be determined also with a DMM, set to diode checker, check, then reverse polarity and check again, you should get a number like 1.4 [I forget the foreward threshold of an LED] and no response the other way...
  Now I'm sorry I've led you astray into territory I can't just type quickly how to do...good thing you have chosen to figure that out first.
  Here's one...you can probably take a regular LED and test which way the circuit lights it, then use that diode DMM check trick to find and connect the Opto's LED the same way.
  I would guess there is a marking on it that denotes the same thing the flat side on an LED does...
  I've run out of vocab...

[petemoore]

  Must Be Anode...seen here is a compressor w/opto...
  http://aronnelson.com/gallery/bcreekmur/flatline_compressor?full=1
  I'll bet the denotation [the dot] on opto's anodes are consistant.

[Bucksears]

Thanks again, Pete.
I know that the short lead on my LEDs is the cathode. I'm assuming that there is no polarity on the LDR, so it can be turned either way. I just need to know which way to turn the LED/LDR combo so the cathode on the LED is in the correct position, if that matters.

- Buck

[petemoore]

  The LED lead orientation DOES matter....
another way to test is [using a resistor so as not to burn out your precocious LED/LDR opto device]...
  Get a voltage and current the LED can handle, connect the LDR to the DMM in say 200k or 2meg R Range setting, connect the LED to the voltage source and watch if the resistance of the LDR jumps...if it changes Rvalue markedly when connecting/disconnecting the Voltage...'ll there 'ya go...
  Orient it so the voltageon the EZ vibe is the same as your test...don't those LEDs go right to ground or 'close'?...Neg Gnd. so that'd be the same as what your voltage test makes work.
  I shouldn'ta typed really, seein' on how I figure the LED's 'my' way...and don't even know how to hook one up...which pole the flat side 'is' on an LED...which pole the flat side connects to when connecting it to a PS...
 

[spudulike]

Is this easier ?

[Bucksears]

THAT'S what I was looking for!
Thanks Spudulike!!