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Posted to uk.d-i-y
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Adding a PSU to a turntable
On 16/04/2019 07:32, wrote:
Hi All,
As some of you are aware, I have an old Sony Midi system complete
with turntables.
In recent years, the only thing Ive used the main boxy bit for, is
to provide 12V to drive the turntable. Id like to feed it from
something a bit more compact. But as usual, have zero budget.
Ive taken the bottom of the turntable and discovered It has a 9
point Something volt motor (it also has an auto Arm liftty and Putty
away mechanism).
I checked the power out from the big box, and its a little over 12V.
I had a dig in my PSU box and the nearest Ive got claims to be 13.1
V.
One silicon diode and one Shottky diode in series will drop a shade
under a volt which should be fine. It is unlikely that something that is
old and designed for a crude bridge rectifier PSU would be particularly
voltage sensitive. The PSU voltage of the original is quite likely to be
load dependant and higher when not spinning up the turntable.
The main thing you need to know is how much current does the turntable
draw at 12v.
Does the team think thats near enough? Or do I need to get Id down?
If so, could I get away with adding a diode (and resistor (value?)?)
in series?
If not, could I add a 12V regulator? Or would I need more than 13V to
feed the regulator?
Although low dropout regulators are available the most common ones need
a couple of volts headroom.
--
Regards,
Martin Brown
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