voltage conversion puzzle.

 

Hello

How would I convert 13.2 volts dc from my motorcycle down to 9 volts dc for
my helmetcam?
Something in-line in the wire?
A resistor?
The camera uses 50 milliamps during operation.
Please reply to

brian_motorcycle_rider@yahoo.com

Thanks for any replies.

;)

 



Yes, for example.


No. You need a voltage regulator, such as a 7809 and a few capacitors. See
for example
<http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref ‘002&Row#2062&Site=US>


--
Dr. Hans-Christian Becker
'96 VN750 SM5TLH KG6POK
Uppsala, Sweden

 

Hans-Christian Becker wrote:


<http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref ‘002&Row#2062&Site=US>

The other solutions provide voltage regulation/safety. If for some
reason your voltage at the battery goes to 20V they will protect the
camera.

If you want to keep it real simple you can just use a couple of diodes
in series from the 13.2 volts to the cam. I would use ~5 1N4001 diodes
wired end to end.

Switched 12V from cycle ->|->|->|->|->|----camera

They only cost about 8¢ each, are good in this design for ~12 Watts, and
should drop the voltage about .8V to 1.2V per diode. 5 is a good
starting place and can be adjusted with the addition or removal of
diodes later.

Rick

 

wrote:


Quick, cheap and dirty:  a 50 ohm 1/2 watt resister in series with a 9
volt zener diode to ground.

 

On Mon, 21 May 2007 13:01:30 GMT, ls650@sbcglobal.net
(Paladin) wrote:


Checking my math, make that a 60 ohm 1 watt, a 1 watt zener, and if
you hook the zener up backwards you'll have zero volts out and will be
smoking the resister.