Continuation of "TOKO Inductors Needed for EM Theremin"

Posted: 12/13/2007 7:52:51 PM
jluciani

From: Massachusetts

Joined: 8/18/2007

Probably. I am going to let you tell me.

Look at the output voltage tolerance, output current, and input voltage range. Compare that to the part that is specified in the Etherwave plans.

The DIP parts are probably OK as well but you
should check the specs.

(* jcl *)
Posted: 12/13/2007 8:00:56 PM
therem13

Joined: 9/25/2007

They have all of the same values, so instead of a probably, I'll make that a definitely.

Please tell me if I'm incorrect, or confirm if I am right...I don't want to order the wrong thing again ;)
Posted: 12/13/2007 9:00:19 PM
omhoge

From: Kingston, NY

Joined: 2/13/2005

hey guys
thanks so much for all the great info.!
side note, if you could line break really long unbroken
urls it would help a lot, they break the layout
on some machines and would save us
extra work.
much appreciated.

[updated later]
Forgot to mention your other option, you can use this Bariliant Portal pattern which is also described in the "Message formatting options" (http://www.thereminworld.com/article.asp?id=14) among the other posting options.

url=http://www.thereminworld.com ThereminWorldurl becomes ThereminWorld
(replacing with [, if I use the real thing it's translated here by the forum engine)
thanks again!
Posted: 12/13/2007 9:13:19 PM
therem13

Joined: 9/25/2007

omhoge, yes, I can definitely do that. I think I have experienced some of the layout problems myself.
Should I edit all the posts containing long urls, or just line break them from now on?

-Dan
Posted: 12/13/2007 10:43:31 PM
therem13

Joined: 9/25/2007

As far as all the questions about me asking if other parts would be compatible with the EM Theremin, I think that I went into this project thinking that I had to get the exact parts mentioned in the plans. However, I've come to learn that a substitute is a substitute, and a theremin isn't really anything too extraordinary and unusually special when it comes down to finding substitute parts. I think that the inductors are important, but as far as these DC regulators go, shouldn't 12VDC at 100mA with 5% tolerance just be 12VDC at 100mA with 5% tolerance?!? The data sheet for the part listed in the schematic and the part I found at Mouser is actually the same data sheet for the two different parts, therefore, I'd like to hope that either one will work. Further, why the heck would a company make two of the exact same thing (RoHS reasons?), because that's a major factor in my uncertainty.

So...I think I'll try to get the alternate part at Mouser, mainly because it has the same characteristics (as far as I can see) and it has a better configuration of the IC and leads.

Also, when it comes to building the cabinet, the plans say not to use any large cabinet parts. However, would two small hinges so that I could open and close the top cover be ok to use? Otherwise, I'm not sure if I'd be able to access the board as easily. Seeing that the front panel is metal, I don't think it could really hurt to add some small hinges...?

-Dan
Posted: 12/15/2007 6:12:08 PM
therem13

Joined: 9/25/2007

At Mouser, the LM prefixed part actually cross-references to the MC prefixed part. However, I'm still not absolutely 100% sure that the MC will work, so I'm reluctant to order...
Posted: 12/15/2007 7:25:09 PM
jluciani

From: Massachusetts

Joined: 8/18/2007

LM is the prefix normally associated with
National Semiconductor. MC is the prefix normally
associated with Motorola (now On Semi).

If the rest of the part number matches exactly
you are usually safe. If the key
specifications match then I would not worry.
Be careful to order the correct package.
Also do not pay for a temperature grade that
you do not require.

(* jcl *)
Posted: 12/15/2007 9:08:28 PM
therem13

Joined: 9/25/2007

Thanks. I'll make sure to get to TO-92 configuration.
Posted: 12/18/2007 5:43:56 PM
therem13

Joined: 9/25/2007

I've mentioned before that there are many places on the theremin schematic the have the earth ground symbol. Should all of these places be connected to the earth ground? Here's a link with a picture (the second diagram in the article) about what I mean:
misctutorials/Ground/grd.html>

I am aware that there are certain components that are polarized, and it matters which way I put them in the circuit. Right now, all I know of is diodes, transistors, rectifiers, ICs, and caps with stripes (I don't think I have any caps w/ stripes). How can I know how to orient them by looking at the component? I can figure out the transistors and ICs, because the orientation is marked on the schematic. However, I'm not sure about the diodes and rectifiers (especially in the power supply).

Thanks,
Dan
Posted: 12/19/2007 10:14:28 AM
therem13

Joined: 9/25/2007

In the plans, the front panel is supposed to be made of sheet aluminum. I do have access to this and can easily make a front panel out of aluminum, but would it be ok to use wood instead? I think the wood would look better.

-Dan

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