Simple Theremin Schem from this site

Posted: 5/18/2006 3:49:38 PM
newbie3

Joined: 5/18/2006

Has anyone tried to build this? I am very new to theremins and electronics in general so I have limited experience with schematics. I don't see where the power supply goes on the schem. Can anyone help out/ walk me through it?

Thanks
Posted: 5/18/2006 11:45:40 PM
kkissinger

From: Kansas City, Mo.

Joined: 8/23/2005

Hi. Please post a link to the schematic. Thanks.
Posted: 5/19/2006 9:35:09 AM
newbie3

Joined: 5/18/2006

http://www.thereminworld.com/pics/schematics/simple.jpg

It's from the Schematics section of this site.

Thanks
Posted: 5/19/2006 10:39:49 AM
Dayfan

Joined: 10/8/2005

Hi,

I would build this "dead bug" on a piece of wood big enough to hold a small transistor antenna in a drilled hole. You can glue the IC's (integrated circuits) on the board upside down close enough together to hook the legs up point-to-point with wire or the other components using a small soldering pencil or iron. I would use a 9 volt transistor battery hooked positive (+) to pins 14 and negative (-) to pins 7. You can find the physical layout of the IC's by doing a Google search on the number. Let us know how it works.

Mark
Posted: 5/20/2006 6:34:24 PM
newbie3

Joined: 5/18/2006

I would only need to hook up the + to both ICs at the points you mentioned and then the grounds? or is it more elaborate?

I'm sorry- it's just that i'm a total noob (hence the username)and need to totally be walked through things.

Thanks all for any help
Posted: 5/20/2006 11:42:26 PM
Dayfan

Joined: 10/8/2005

It's as simple as that. Be sure to get the pin locations correct by looking up the physical layout and being sure you are looking at the IC from the top or bottom as appropriate.
Posted: 5/23/2006 11:28:54 AM
newbie3

Joined: 5/18/2006

Thanks! I let you all know how it goes.
Posted: 5/24/2006 10:21:19 AM
newbie3

Joined: 5/18/2006

Wait!!!! I have yet more questions. Close look at the scheme shows the 29k resistor connected to the bottom 4093 has a diagonal arrow through it. What does that mean? Also, i just want to make sure... the cap just before the "ausgang" is an electrolytic, and the - is connected to "ausgang" (output)? That's what I can gather..

The resistors at the 4093- are they in fact connected to pin 3 or connected to the circuit after pin 3? I read it as after...

Lastly (i promise)- at pin 1 for each 4093 I see a +. I assume that that is the + for the 100 pf cap? does that mean it's electrolytic?

How do I ground something that's stuck to wood?

Thanks Dayfan for your advice and in advance to anyone else who responds!
Posted: 5/25/2006 11:35:22 PM
wgardiner

Joined: 5/17/2006

the resistor between 2nd and 3rd pins 4093 isn't a normal resistor, its a potentiometer aka pot. It's a variable resistor, but the middle lug isn't being used. I'm not sure it's a 29k it looks like 20k to me.

I'm not sure whether or not the 1uf is an electrolytic whoever drew this schematics uses weird symbols, but maybe youve seen ones like this before. On an online translator german to english ausgang = exit so I'd agree with you that thats the tip of the out.

It doesn't matter whether or not the resistors connected to pin three or the circuit after pin three as long as its before the 4077, but use sockets instead of soldering to the pin since it would probably overheat and break the ic.

I doubt that the plus on the 1st pin is a connection to the 100pf cap because caps only have two leads. I also don't think its electrolytic. I'm think that the +'s are a connection for the +9v.

The ground is connected to the - and the grounds are all the thick black lines I'm pretty sure but not 100% because it's drawn weird. I wouldn't be too worried about the grounding, just attach the ground lug to something.

I wouldn't build it on a board. I mean you could, and it would work fine it's just a bit strange. I would prototype it on a breadboard (not literally a board). Especially since it would be easier and you can test it first. You could use a board and it would be alright as just a way to keep them anchored.
Posted: 5/26/2006 1:30:58 PM
newbie3

Joined: 5/18/2006

So does that mean pin 1 to the + of the battery and pin 14 (like it says on the scheme)? That doesn't seem right.

Ur right it is a 20K. I'm calling my eye doctor!

Thanks

You must be logged in to post a reply. Please log in or register for a new account.