In article ,
wrote:
On 17 Jun 2005 15:29:32 -0700, wrote:

[ ... ]

When I try my values for R, L, and C, the program says, in effect, "No
resonance".

Still with 30 ufd across the main winding, 1 VAC is present, and a
mighty clean sine wave at that.

I have ordered a 1 pole, 12 position switch and will add 10 ufd per
position. It's a shorting switch. I may build a second switch up with
50 ufd per position. We will see....

Hmm ... consider the following:

1) One four-pole 12 position switch

2) One 10 uF capacitor.

3) Two 20 uF capacitors.

4) one 40 uF capacitor

Wire switch so in the following positions you have the following caps
connected:

0 None

1 Single 10 uF

2 Single 20 uf

3 One 20 uF and one 10 uF in parallel (30 uf total).

4) Two 20 uF in parallel (40uF total)

5 Two 20 uF and one 10uF in parallel (50 uF total)
or
One 40 uf and one 10uf capacitor in parallel (50 uF total)

6 One 40 uF and one 20 uF in parallel (60 uF total)

7 One 40 uF and one 20 uF and one 10 uf in parallel (70 uF total)

8 One 40 uf and two 20 uf in parallel (80 uF total)

9 One 40 uF, two 20 uF and one 10 uF in parallel (90 uf total

So -- you have 0-90 uF in 10 uF steps from four capacitors. This is
pretty much how capacitor decade boxes are made.

If you want to extend the range a bit, add another 20 uf (and another
deck) and you can get up to 110 uF from 12 steps.

Essentially, each capacitor has its own deck, and which are
connected in is determined by the wiring to the terminals of the switch.

I would suggest avoiding the switching while it is powered, as
it will burn the contacts each time you switch.

An alternative way would be to install one toggle switch for
each capacitor, and simply sum the values of the switches which are on.

Enjoy,
DoN.
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