🚀 go-pugleaf

Babak Sehari (sehari@iastate.edu) wrote:
: 
: There are many ways to do this the cheapest way is to put:
: 
:   12-3
: --------- = 13 diodes in series with the input voltage of your CD player,
:     0.7
: 
: Like this:
: 
: +12V -|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|- +3V
: GRD  --------------------------------------------------
: 
: The problem might be generated if the input voltage swings.  To avoid
: this problem try putting a 2N3055 transistor as follows:
: 
: +12V |>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-|>|-    ---+3V
:                                         | \_/ Emitter
:                                         R  |
:                                         |--|
:                                         |
:                                         ||>|-|>|-|>|-|>|-|>|-|
:                                                              |
: GRD ---------------------------------------------------------+-----
:                                     
: 
: R=1000 ohm
: Trans=2n3055
: Diodes= 1N4001 or 1N4005
: 
:                          With highest regards,
:                               Babak   Sehari.
: -- 

Sorry but all this is nonsense bcause of the high current. If you realise
a linear regulator you will generate very high lostpower. In this example
will be 0.6A * 9V = 5.4W. The better way is to build a switched regulator.
The advandage is the high efficiency ang therefore less powerdissipation.
There are many ic which can do this with a few additional components. 
Take the Switching-Regulator L296 from SGS-THOMSON. There is a kit with
pcb-board and the needed components. Ask a SGS-THOMSON-Distributor.

So I hope I can help you.	Greeting from Thomas