How can I swing R

[breather-resistor]

I am looking for a way to make a circuit that increases and decreases R at a rate and depth that I select.  Is this possible?

any help would be appreciated.

Breather

[Seljer]

point a blinking led at an LDR

study the pedals at http://www.commonsound.com/kits/doku.php for a couple of examples on how to hook up an LFO to a LED

[breather-resistor]

Is there a way I can make it so that I have two blinking leds that are in opposite phase?

[petemoore]

  I came up with an easy way to do that mechanically, but very soon that was snatched up/claimed, and I got chastized for talking about it honestly....I'm not interested in doing chronological studies to determine who typed about it first [I remember that just fine].
  But there's certainly a way to do it electronically...
  Take the *LdR which has the 1rst blinking LED, use *that resistance change to trigger the second LED in opposite way [when one LED lights..the change in resistance of the first LDR controls a second LED to become unlit.
  But there's probably a simpler way to do it electronically...hmm.
 

[breather-resistor]

Pete thanks for your help that definitely makes SOME sense.  I would love to get a look at your idea.

I'm not an advocate of anyones proprietary toes getting stepped on here and I come down on the side of manufacturers that have an interest in protecting their designs.

However, I am no entirely sure how this particular function could be a proprietary technology so to speak.

[breather-resistor]

Take the *LdR which has the 1rst blinking LED, use *that resistance change to trigger the second LED in opposite way [when one LED lights..the change in resistance of the first LDR controls a second LED to become unlit.

How could this be done?

[Papa_lazerous]

rather than using opto-couplers or LED/LDR combos could you just have a FET to provide the variable resistance and control that with an LFO, if you wanted to have 2 LED's switching alternately you could do this easily also.  And if you have an decade counters handy you could have the 2 LED's on there and switch a FET from the decade counter and put a cap across the FET so not only do the LED's alternate but the cap draining would make the LED's switch off softly and fade as the other lights. you can also do nice trailing light displays this way...  Food for thought I hope

[breather-resistor]

papa lazerous,

can you go into more description of how these two methods would work, or how you would implement them?

[DougH]

Go read Mark Hammer's excellent article on envelope followers at GEO. He does a good job explaining various "variable resistor" techniques such as LED/LDR, FET, etc...

[Paul Perry (Frostwave)]

Out of phase flashing leds?
here's how: http://www.techlib.com/electronics/flipflopflash.htm

[Papa_lazerous]

Out of phase flashing leds?
here's how: http://www.techlib.com/electronics/flipflopflash.htm

nice link, just a thought you could be real cunning and use a 4013 chip and do it with that with virtually no external components....

[breather-resistor]

Thank you Paul, that is a great link.

papa lazerous can you diagram how that would work.  I have never used a decade counter before.

[Papa_lazerous]

Thank you Paul, that is a great link.

papa lazerous can you diagram how that would work.  I have never used a decade counter before.

4013 flip flop would be a better option if you want just 2 LED's out of phase, the decade coutner would be overkill I was just saying if you had some laying about like I do... its a 4017 btw

it was just food for thought to expand apon ideas, a google search will give you some basic examples, I just tried it

[miqbal]

here's how: http://www.techlib.com/electronics/flipflopflash.htm

Now I know how the flashing lamp of a police car works...