maintaining 12 V

hi.
well i have to implement an intelligent lighting system. after
detecting the person from PIR sensors, light has to be switched on for
some time only at night time. Im using a 12 V battery as a power
source which is powered by solar pannel.
im having the problem in keeping the battery output constantly at 12
V, because after sometime the voltage is bound to drop, and the
circuitry will not work properly in fluctuating voltage.

 

[Bob Monsen]

<aqe911@hotmail.com> wrote in message
news:b914d85f-969d-49a2-8c42-65db37cb2805@56g2000hsm.googlegroups.com...

hi.
well i have to implement an intelligent lighting system. after
detecting the person from PIR sensors, light has to be switched on for
some time only at night time. Im using a 12 V battery as a power
source which is powered by solar pannel.
im having the problem in keeping the battery output constantly at 12
V, because after sometime the voltage is bound to drop, and the
circuitry will not work properly in fluctuating voltage.

You need more batteries!

Also, Google for 'sepic'.

Regards,
Bob Monsen

 

[Jamie]

aqe911@hotmail.com wrote:

hi.
well i have to implement an intelligent lighting system. after
detecting the person from PIR sensors, light has to be switched on for
some time only at night time. Im using a 12 V battery as a power
source which is powered by solar pannel.
im having the problem in keeping the battery output constantly at 12
V, because after sometime the voltage is bound to drop, and the
circuitry will not work properly in fluctuating voltage.
if you used lower voltage circuitry, you can thus use a regulator

to operate the control electronics.
5 volt operation is common.

to keep your unit not working during light hours, employ a photo
cell that inhibits the circuit. Just mount it behind a lamp so it
won't see it self and oscillate.

If you take a part one of those cheap out side automatic flood
light systems, you'll find most likely the internal electronics
operates on low voltage. You have every thing you need there.

http://webpages.charter.net/jamie_5"