REQ: 12V Power Supply Help

[[news]]

hi all

I've popped the top off my panasonic RX-ES27 stereo CD player

http://www.clubic.com/photo/00032400.jpg

I've located the power supply, sussed out the +ive and GND terminals
on the secondary side and got an output reading of 15.37V

I intend to power the device off a 12V car battery and they usually output
13.8V or thereabouts. does anyone forsee any problems I might have as
it's only 1.5V under ? (better than over I suppose)

I intend to cut and bare the + and GND output leads and solder on the
appropriate flyleads and route them through the battery compartment
onto a fused cigar lighter type plug.

here's the crux of the matter, should I just power it off the battery, neat,
with the fused cigar ligher type plug or should I use a regulated 12V
gigar lighter plug ?

in the past I've done a similar bodge with crocodile clips to the battery terminals
which worked fine, if a bit dodgy. I want this to be a fixed mod for use when
camping and boating where there's always a12V DC socket

tia for any help



RT

 

[Rich Grise]

On Mon, 09 May 2005 13:56:59 +0000, [news] wrote:

hi all

I've popped the top off my panasonic RX-ES27 stereo CD player

http://www.clubic.com/photo/00032400.jpg

I've located the power supply, sussed out the +ive and GND terminals
on the secondary side and got an output reading of 15.37V

I intend to power the device off a 12V car battery and they usually output
13.8V or thereabouts. does anyone forsee any problems I might have as
it's only 1.5V under ? (better than over I suppose)

I intend to cut and bare the + and GND output leads and solder on the
appropriate flyleads and route them through the battery compartment
onto a fused cigar lighter type plug.

here's the crux of the matter, should I just power it off the battery, neat,
with the fused cigar ligher type plug or should I use a regulated 12V
gigar lighter plug ?

in the past I've done a similar bodge with crocodile clips to the battery terminals
which worked fine, if a bit dodgy. I want this to be a fixed mod for use when
camping and boating where there's always a12V DC socket

tia for any help

It will work, with the addition of one component - a Transzorb such as a
1.5KE16 (1N6276) or so: http://www.vishay.com/docs/88301/15ke.pdf .
You should be able to get one at almost any electronics vendor. Put it
just like a Zener across the +12/gnd, between the plug and the box,
cathode (band end) to +12, and anode (blank end) to ground.

Car +12V is terribly nasty noisy crappy DC - I've heard there can be
spikes of 60V or worse. You might even want to add a hash choke and
filter cap.

Good Luck!
Rich