Need advice to find a simple circuit to play with vactrol

[Le québécois]

Hi,

I'm looking for a circuit that can light a LED and fade a second one simultaneously with one potentiometer for control. When the pot, is max, one LED is fully on and the other is fully off and vis-vers-ça.
Any idea? Or keyword for me two do some more efficient search. I have already tried some like "LED dimmer circuit", "Alternate LED flasher" with no success.   

I'm working on a wah anti-wah circuit with LED/LDR and twin-t circuit.

Charles

[armdnrdy]

Off the top of my head I'm thinking bipolar switching and a RC time constant circuit. Or...maybe some sort of comparator circuit.

I'm sure someone will pop in with a good path to lead you down.

Sounds like with the things you want to accomplish breadboarding and a little experimentation would be the way to go.

[Le québécois]

The beast is already on the breadboard with good succes (a signal splitter feeding two Twin-t wah and mixed back to one signal at the end). My only problem is to have perfect synchrony (one up one down) between my dual LED/LDR.
at the momment, i'm using a LED dimmer circuit to control the first LDR in one Twin-T and a second LED/LDR is link to the inverse LDR action circuit from deadastronaut. It work but the sensitivity of the reverse LDR circuit is diffrent (more like on and off). Overall it work but we can ear that the sweeping is not really reversed.

charles 

[armdnrdy]

Do you have a schematic drawn up?

It would be easier to see what you have going.

[Le québécois]

No schematic but here is the principle followed by a link to the schematic of the circuit I use to control LED1 and 2.


http://www.seekic.com/blog/project_solutions/2011/08/22/30_mA_LED_Dimmer.html

The idea would be to remove the reverse action LDR circuit and the third LED/LDR.
The led dimmer circuit actually work quit well for one wah and is easely tweakable to match any LED/LDR range. If I could modded it to control two LED in opposite direction at the same time it would be splendid. 

[kimelopidaer]

Hi.
There is a .pdf called "1-100 transistor circuits" available on Google.
I have seen something in there that you could apply to your circuit.
K