TOKO Inductors Needed for EM Theremin!

You are not looking for a transformer with
a ground (which would be earth ground). The
transformer has a line, center-tap and neutral.

It is a very common part that you can get
at Digikey, Mouser or Radio Shack.

(* jcl *)

Is the center-tap an actual wire that is an output of the transformer? As far as the schematic goes, it doesn't specify where the center-tap or neutral wires are attached to the circuit.

How does the ground work if it's not an earth ground? If there is no earth ground, does that mean a 2-Prong plug can work? How is the theremin grounded without an earth ground?

What's the difference between an adapter and a transformer? This seems to be a discrepancy in what I'm looking for.

Does anyone know of an example of the type of transformer that I need (not necessarily the values I need, just the characteristics?)

Thanks

When you mentioned you thought you needed a
center-tap transformer I must have misread it.

For a bridge rectifier you need a center-tap
which is a separate wire. For this circuit you
just need a line and neutral. The Hotrodding
the Etherwave schematic shows that neutral
and earth ground are connected (pin 2 and 3 on
the DIN connector).

(* jcl *)

A transformer provides isolation and sometimes
a voltage conversion (step-up or step-down).

Adapters come in a wide variety of models.
You can get an AC-AC adapter (which is essentially a transformer), AC to unregulated DC adapter, an AC to regulated DC adapter.
The DC conversion may be done with linear
regulators but could be done with a switch-mode power supply. I believe the majority of adapters provide isolation.

(* jcl *)

So if all I need is a line and neutral, how is the theremin grounded?

If what I understand is true, and all I need is in fact that line and the neutral, so something like http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=T601-ND would work. Is this true?

This is backtracking a bit, but could pots from RadioShack work instead of the Digi-key ones you used. They have a high enough wattage rating and the correct resistance. Is the quality of RadioShack parts adequate?

I'm wondering about the RadioShack pots because I think I'll have an easier time finding knobs for them.

Here's the link: http://www.radioshack.com/product/index.jsp?productId=2102789&cp=&fbn=Type%2FPotentiometers&f=PAD%2FProduct+Type%2FPotentiometers&fbc=1&kw=pot&parentPage=search

Thanks,
Dan

I believe that the EM Theremin has an earth ground
on the DIN connector (I believe it is pin 2).
Check out the power supply section in the Hotrodding
article.

If you build your own power supply you would use
the earth ground prong of the 3 pin AC connector.

(* jcl *)

I have no experience with RadioShack pots.
For this application I would be surprised if
you had a problem.

Knobs should not be a problem for either style
pot.

(* jcl *)

I haven't been able to find any AC to AC transformers/ adapters with 3 prongs where I could have access to an earth ground...they all simply have 2 prongs for the input.

From what I see in the diagram, the earth ground is then attached to one of the other wires. Is it the line or neutral?