One power source two different ground

[clydeshere]

Ok sorry for my limited computer skills ill try sending this 2 ways because I don't think the quality is good enough to see when there combined.

LDR + boost the theramin control wire goes to the proximity control between D1 and Q1. I think the boost is correct but I don't use Vero so sorry if theres a mistake I know it's correct on my bread  board.


http://dl.dropbox.com/u/15134989/ldr%20%3D%20boost.gif

and this is my attempt to tie them both together but I dont think youll see it lol


http://dl.dropbox.com/u/15134989/theravolume.jpg

[jasperoosthoek]

Diagrams are a bit hard to understand because they only show how to connect the components, which I don't care about until I build it. They require some effort to read. A schematics shows how a circuit works. Schematics look like this: http://dl.dropbox.com/u/15134989/schem2.gif I could make a schematic myself but I have other things to do today .

The audio ground should be the same as what you call the theremin ground. Just use only one ground.  Did you notice that the output black and red wire go to parts in the circuit that are directly connected together? Right now the audio ground is actually the signal output! This means that nothing comes out of the boost circuit and you cannot pass a signal into the circuit as well. Just connect all the back wires to what you call the theremin ground and forget about the signal ground. 

What exactly is the function of LDR1? It looks like you try to mimic a potmeter, one LDR goes up, the other goes down. Only LDR2 is enough because you already have the 330k resistor in there. Also D1 is connected to the signal output! Take it away as fast as you can as it will lift the output voltage to almost the supply voltage and put a wrong voltage on the 10uF cap which will short over time. So take LDR1, D1 and R2 out of the circuit and connect LDR1 and R2 together.

Also disconnect the LED from the proximity control when you connect to the LED in the other circuit. LEDs don't work well in parallel. A red LED for instance will always draw more current than a yellow LED for instance. Tto connect more LEDs together you should connect them in series.

Anyway, lots of comments. But I believe it will work soon. Good luck!

[clydeshere]

LOL i knew there was gonna be questions about the grounds I put them this way because i have tried both ways and it doesn't seem to make a difference. The point of the LED's being different colors is that one needs to be brighter this helps the signal flow through it better. Trust me when i say the different components work exactley how I want them to when they are indepentdent of each other. And I originally didnt post the LED part of the circuit because I knew it would only confuse things.

[clydeshere]

Yah i could go through the whole process of what the LED's do there theramin ciruit doesn't let one go up and one go down so this way one is on all the time and the other one overrides it and turns the signal off. And the resistor is there because some signal in an LDR always leaks through so this helps it turn all the way off. But also I know is the cause of some of the volume loss.

[clydeshere]

Here's the prximity and LDR's tied together any sound u here is just before the volume swell is just my guitar sittint to close to the mic on the camera.
http://www.youtube.com/watch?v=9X4DcupPdp0

Ok really crazy idea what if i took the 9 volts used a doubler than split them into two different 9 volt circuits. I know prob wont work because theyd  still be tied into the original ground.

[jasperoosthoek]

Congratulations that you got it working.  But you raise more questions that I can give answers to.

LOL i knew there was gonna be questions about the grounds I put them this way because i have tried both ways and it doesn't seem to make a difference.

I'm pretty sure you didn't build it as in the diagram because your output should be shorted  . There is a direct connection between the black and red wire of the output wire in the diagram. It's the big jumper wire. There should be no sound at all if you built it like that.

The point of the LED's being different colors is that one needs to be brighter this helps the signal flow through it better.

I'm completely lost here  .

Trust me when i say the different components work exactley how I want them to when they are indepentdent of each other.

That's weird. Did you put a bypass cap between the ground and the 9 volts supply? Maybe the RF of the proximity circuit somehow plays tricks on the boost.

What exactly is the function of the red LED? Is it optically connected to LDR1? You seem to run DC through it and it is connected to the signal output not ground. That's one thing to fix. You are probably going to blow up C2 if it has a reverse voltage across it.

Yah i could go through the whole process of what the LED's do there theramin ciruit doesn't let one go up and one go down so this way one is on all the time and the other one overrides it and turns the signal off. And the resistor is there because some signal in an LDR always leaks through so this helps it turn all the way off. But also I know is the cause of some of the volume loss.

Why not skip LDR1 and D1? They don't seem to have any function at all. Or do you mean that you use them to turn everything off optically? I don't think that what you want is impossible, I'll think about how to turn one on and the other off at the same time.

Here's the prximity and LDR's tied together any sound u here is just before the volume swell is just my guitar sittint to close to the mic on the camera.
http://www.youtube.com/watch?v=9X4DcupPdp0

Nice! 

Ok really crazy idea what if i took the 9 volts used a doubler than split them into two different 9 volt circuits. I know prob wont work because theyd  still be tied into the original ground.

That wouldn't work. But it seems to work in the YT video. What exactly is the problem with the grounds?

[clydeshere]

Yah the video is just the proximity circuit without the boost.

And the reason one LED is on all the time is that that acutally lets the sound through. Then when the other led goes on it turns the sound off. I actually think this works out better even though it's the opposite of what a normal volume pedal does. It allows the sound to be on all the time then when foot is on the Plate the sound is off.

Ok and the basic problem is that the LDR's cause a volume drop. I think thats just how they are. The same thing happened when I built a tremelo with LDR's. so thought i would add the boost circuit onto this. I used to beginer project from this site.

    BUT and this is were the problem is. When u run the proximity circuit and the boost circuit together they affect each other in a bad way.
My theory and believe me I could be wrong is that because the proximity is affecting the power turning the LED up and down and the Boost i think shunts more power to ground that they are being affected. when they are hooked to the same power source the volume on the boost doesnt work and the LED's dont smoothly go up and down just kind of off and on.

[clydeshere]

Oh and the red LED is a super bright its just on all the time. Super bright lets more sound through.

[jasperoosthoek]

Oh and the red LED is a super bright its just on all the time. Super bright lets more sound through.

If you take it out it will let even more sound through.

[clydeshere]

Yah but the volume wont get down to zero there its based off a LDR volume pedal but if someone could figure out away to make one LED go up while one goes down it might help the volume drop.

[clydeshere]

Kind of based on this circuit and me tinkering. sorry i cant save it rotated.



http://dl.dropbox.com/u/15134989/plaes.pdf

[jasperoosthoek]

Yesterday I designed a little circuit to have a second LED go down when the first goes up. All you need are a couple of extra resistors, a trimpot and a 2N3906. Unfortunately I didn't have my imageshack password with me. I'll post it soon.

[clydeshere]

Yesterday I designed a little circuit to have a second LED go down when the first goes up. All you need are a couple of extra resistors, a trimpot and a 2N3906. Unfortunately I didn't have my imageshack password with me. I'll post it soon.

Cool maybe I can get rid of some of the volume drop. Ill have to figure out away to make it so that the volume turns off when your touching the anttena but shouldn't be a problem.

[jasperoosthoek]

If you use two LDRs with 'opposite' LEDs you can get rid of the 330k resistor. Also, the it will go to zero much better and there will be almost no volume drop when fully open.

Wednesday I'll have some more time to post it. The coming days I'll be away for work.

[clydeshere]

If you use two LDRs with 'opposite' LEDs you can get rid of the 330k resistor. Also, the it will go to zero much better and there will be almost no volume drop when fully open.

Wednesday I'll have some more time to post it. The coming days I'll be away for work.

WEDNESDAY !!! ok I think I'm getting the enclosure for this around the anyway. LOL patience not my virtue. 

[clydeshere]

Thanks for the help on this!!!!!

[PRR]

I can't make out WHAT that 'gator control is supposed to do.

It sure is not a drop-in for what you have.

And putting the LEDs in parallel makes trouble.

SIMPLIFY!!

You have an LED that gets light-and-dark when you move, your foot, yes?

The basic opto-fader is one lamp and one LDR.

Bust the prox-board LED off, or put the LDR next to the prox-board.



Does that work?

[clydeshere]

I can't make out WHAT that 'gator control is supposed to do.

It sure is not a drop-in for what you have.

And putting the LEDs in parallel makes trouble.

SIMPLIFY!!

You have an LED that gets light-and-dark when you move, your foot, yes?

The basic opto-fader is one lamp and one LDR.

Bust the prox-board LED off, or put the LDR next to the prox-board.



Does that work?

No doesn't work LDR's never get to zero volume hence the need for two. And I've built two pedals now usind LDR's and there seem to alway's be a volume drop just because an LDR si a resistor so with 2 I think might bump the volume up.

the only thing i could figure out with that cirtuit is why theres two LED's one on one off and one on all the time i built one with a Potentiometer control and it worked fine with just the 2 LED's.

[clydeshere]

couldn't figure out sorry.

P.S. I'm leaving the LED in the circuit with the potentiometers controls in the proximity control. I've actually seen theremins in use and it seems whenever there put in different situations that react completely differently. So I'm going to leave the LED in the circuit and mount on the enclosure so I can make changes in different situations.

[jasperoosthoek]

Just checking this in my hotel room before I go to bed. I'll try to post my super simple idea tomorrow. Hope it works.