Colin- your simple Dual LFO

[expanoncolin]

When it's opposite ground it will pulse, but not when the resistance between the output and the LED is too low. 

When I fade more to ground the maximum brightness of the LED gets dimmer and dimmer, as it should. 

So, unless I'm confused, it sounds like it works as you want it to except that the LED output gets too bright?  Couldn't you just fix this by adding series resistance?

-Colin

[SpectralJulian]

Yes I could. 

My problem is isn't that it doesn't work, just that it will work opposite as to how it should. 

When I decrease the overall brightness of the LFO output to LED, I'm also increasing the LDR's minimum resistance, which I don't want to do.  I want the depth to decrease the LDR's maximum resistance.  I can already increase the minimum resistance by turning up the potentiometer that is in series with the LDR. 

I've tried wiring the LED up for inverted output and that doesn't seem to work too well either.  In fact, it works worse. 

[SpectralJulian]

I'm thinking perhaps I'll leave it how it is and later revisit it.  I'm sort of at the point where I just want to get this done.  I was playing around with it, and as it is, it sounds cool. . . it's just not perfectly tweakable.

[mikebike]

i dont think you need a vactrol to conect the lfo to the PWM....

[manuhoz]

Dear Colin,
I try to create your simple LFO, but it seems that it's not simple enough for me :p
I'm a very beginner  in electronic and I'm French so I speak broken english as well.
Anyway I try to follow the schematics and I have nothing on the output when I plug it to a guitar amp. (maybe it's normal ?)

What I want is something simple to generate a frequency audible in a speaker in between 0 and approx 48khz square or triangular.

I Use a 4558 IC, a 1uF for C and a 47uf electro for generating the Vb.

A/ I'm not sure I plugged correctly the potentiometer, I mean is it always like on the drawing with the middle, being the middle pin ? Is that important if you invert the left and right pin on the potentiometer ? I is normal one of the pin of the 100k speed is not plugged ? it should be on the gnd ?

B/ Is it normal that I measure 9V at Vb

C/ I use 87kohm for the close 100k resistance, Is that too close ?

Please help

Manu

[expanoncolin]

A/ I'm not sure I plugged correctly the potentiometer, I mean is it always like on the drawing with the middle, being the middle pin ? Is that important if you invert the left and right pin on the potentiometer ? I is normal one of the pin of the 100k speed is not plugged ? it should be on the gnd ?

Yes - one wire to the middle pin, one to one of the side pins - doesn't matter which.  One lug should be disconnected completely.

B/ Is it normal that I measure 9V at Vb

No, you should measure close to 4.5V. If you're measuring 9V, something is wrong.  Triple check your wiring, or re-wire it.

C/ I use 87kohm for the close 100k resistance, Is that too close ?

87k shouild work.  You can also try 68k.

-Colin