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From: ycy@walt.cc.utexas.edu (Joseph Yip)
Newsgroups: sci.electronics
Subject: 12V to 9V, 3V (from car)
Message-ID: <34133@ut-emx.UUCP>
Date: 16 Jul 90 18:14:02 GMT
Sender: news@ut-emx.UUCP
Reply-To: ycy@walt.cc.utexas.edu (Joseph Yip)
Lines: 19

Hi,

There were some discussion on conversion from car +12V to +5V.
I am interested from +12V to +9V or +3V. I need 9V or 3V to power my
cassette player or walkman. 

What kind of voltage protection, DC-to-DC converter, voltage
regulators, do I need? Normally voltage regulators are either 5V or
12V. How good is a variable voltage regulators?

I was thinking of using a zener diode IN4728 (3.3V) and IN4738 (8.2V) 
because they seem to give me the best voltage approx. However, the
diodes will be constantly drawing current. 

Thank you.

- Joseph

Email: joseph@zeus.ee.utexas.edu