noise: re Dynamo help
jim at well.com
Mon Jul 22 04:00:48 UTC 2013
assume some AC voltage coupled to a
transformer. If the transformer is 1-1,
then the secondary will present the same
voltage swings as the primary windings.
Note that a transformer has a current
limit, essentially a function of the
insulation on its windings as well as the
saturability of its core and winding
Note also that a transformer has
frequency limits, which may be a small or
large range as well as very low or full
audio or very high (e.g. radio) frequency
For starters you can probably get
away with using a power transformer,
and you can use its labeled primary as
a secondary (and its labeled secondary
as the primary). One typical power tranny
is a step-down transformer, taking 120 VAC
in and putting out 12 VAC, which makes it
a 10-1 step-down transformer, or, wired
in reverse, a 1-10 step-up transformer.
A trick: get two identical transformers
and wire their secondaries together, then
input an AC voltage on one tranny's primary
and you'll get that same AC voltage on the
other tranny's primary windings (remember
that the secondaries are wired together).
On Sun, 2013-07-21 at 17:46 -0700, Johny Radio wrote:
> jim jim at well.com
> Sun Jul 21 21:43:25 UTC 2013 wrote
> >>A different approach, assuming AC from the "dynamo", is to feed it
> to a transformer, even a 1-1 tranny, and feed the audio amp with the
> tranny secondary (with recitfier
> and conditioning circuitry between the secondary and the amp's power
> input stage).
> -- interesting, will try! How would a 1-1 tranny affect my signal?
> Johny Radio
> Stick It In Your Ear!
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