On Sun, 12 Jul 2009 11:58:58 -0700, "Zootal"
wrote:

snip


A 7809 converts to 9V, not 5V.

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200µF capacitor?

Why not 10?

Why not 1000?

JF


Forget the regulator. Connect 4 diodes in series with the power supply and
that will get you into the ballpark.

---
But, (although it may not matter if the recorder's motor speed is
maintained constant by the recorder itself) the output voltage will fall
as the battery voltage does.

JF