Whenever I'm in the car listening to my
favourite CD, it always happens-my batteries go dead. To
solve that problem, I built this extremely simple
regulator circuit. It steps down the 12V from the
lighter socket to 9V which is used by the CD player.
Different CD players (I have a Sony Discman) may require
different voltages, so just use the correct regulator.
All the 78xx series regulators have the same pin out, so
the circuit is universal.
Schematic
Parts
Part
Total Qty.
Description
Substitutions
C1
1
1000uF 25V Electrolytic Capacitor
C2
1
10uF 25V Electrolytic Capacitor
C3
1
1uF 15V Elextrolytic Capacitor
C4
1
0.1uF 15V Electrolytic Capacitor
U1
1
7809 Or Other Regulator (See "Notes")
See Notes
MISC
1
Cigarette Lighter Plug, Plug For CD Player
(See "Notes"), Heat Sink For U1, Wire, Case.
U1 1 7809 Or Other Regulator (See
"Notes") See Notes
MISC 1 Cigarette Lighter Plug, Plug For
CD Player, Heat Sink For U1, Wire, Case.
Notes
The voltage your CD player needs will
determine which regulator you use. For 9V, use the 7809.
For 6V, use the 7806. For the unlikely 5V use the 7805.
Remember that whatever regulator you use, you will need
to heat sink it. The metal case or metal cover on the
case makes a great heat sink.
I built the circuit in a small case
with the long wire to the cigaratte lighter plug coming
out one end, then another, slightly shorter wire going
out the other end to the CD player.
Triple check your wiring. You would
hate to ruin an expensive CD player because you reversed
one of the connections or hooked the regulator up
backwards.......