Re: Circuit Power Consumption

On Mon, 26 Jun 2006 13:33:42 -0500, John Fields
<jfields@xxxxxxxxxxxxxxxxxxxxx> wrote:


---
Neglecting the buzzer for a moment, if the rest of the circuit draws
500 microamps from the battery, all the time, and the battery has a
capacity of 500mAH, that means you can expect about 1000 hours out
of the battery. About 6 weeks.

If the buzzer needs 50mA and it runs for 15 seconds a day, that's
only increasing the load on the battery by about 9 microamps, so the
life would still be about 6 weeks. The trick here would be to get
the timer to run on as little current as possible. I think 100
microamps is doable and that would get the life up to about 10000
hours. About 417 days.

---
Oops...
Checking Eveready's site gives 625mAH for their 9V alkaline, so with
a 100µA load that's 6250 hours, or about 260 days.



--
John Fields
Professional Circuit Designer
.

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