Power supply to run camera and 555 timer

[DorkyGrin]

I'm looking for ideas for building a power supply (out of batteries)
bank that will run a 555 timer circuit and a Kodak Digital camera. The
camera takes a 3vdc supply. I have a number of 555 timers but I think
they take at least 5 volts to work.

For the camera, I'm thinking of building a circuit that will activate
the focus button, then a couple seconds later activate the trigger.

I'd like to use the same power supply but have it as efficient as
possible. What's the most efficient way of using a 6V gellcell battery
to supply both 3vdc camera and 5vdc 555 timer trigger?

Thanks

 

[John Fields]

On Mon, 28 Jul 2008 10:15:11 -0700 (PDT), DorkyGrin
<DorkyGrin@yahoo.com> wrote:

I'm looking for ideas for building a power supply (out of batteries)
bank that will run a 555 timer circuit and a Kodak Digital camera. The
camera takes a 3vdc supply. I have a number of 555 timers but I think
they take at least 5 volts to work.

For the camera, I'm thinking of building a circuit that will activate
the focus button, then a couple seconds later activate the trigger.

I'd like to use the same power supply but have it as efficient as
possible. What's the most efficient way of using a 6V gellcell battery
to supply both 3vdc camera and 5vdc 555 timer trigger?

---
CMOS 555s like Maxim's ICM7555 will run down to 2V, so the best thing
to do would be to use a buck converter to get the 6V down to 3V and
then to run the timers and the camera both from 3V.

JF