Ashley,

As you're probably aware the original API-Delevan inductors were
rated;
220uH was 2.025A
1000uH was rated 0.39A
so this gives you a clue as to the 'minimum' you should be looking
for.
You can go above this, but as others more knowledgable than me will
tell you, everything kind of impacts on everything else and a balance
has to be achieved.
I would look at what Jaycar or similar has or try looking at say the
Coilcraft range (I don't know who might stock it in Aus) as they will
have something to suit.
You could go for 100uF/ 25V at C1 and anything up to 6,800uF for C4,
the voltage arting of C4 should be at least double the battery
voltage.

For prtection youi should also put a 15V zener parallel to C1 to
protect against spikes.

Regards

Richard

--- In randrdesulfatorforum@yahoogroups.com, "Ashley" <tty07@...>
wrote:
>
> Hello, I'm glad to find this group as I've been reading the ezboard
> web forum but it appears to be more or less deceased. I'm in the
> process of building the basic, simple, original Alastair Couper
> desulphator comprising 13 components.
>
> I either already have, or can order all of the components but the
> chokes are throwing me for a bit of a loop. I've consulted with
> someone much cleverer than I (I'm an electronics ignoramus) who
> advised that two chokes I'd selected as potential candidates would
be
> unsuitable as they're only rated for 155mA.
>
> I can get the 220uH choke rated for 5A, and a 1mH (which I presume
to
> be the same as 1000uH) rated at 1.6A. Would this be sufficient? If
> the lower current ratings will do that would be great because
they're
> significantly cheaper, but since I'm only making 4 it probably won't
> matter that much.
>
> Also, will it be ok to substitute a 33uF 25V for C1 (should be 30uF
> 16V) and 100uF 25V for C4 (should be 100uF 16V)?
>
> Any advice gratefully received.
>
> Cheers,
> Ash
>