[sprite_tm] sent in this nice little single AA battery micro-controller power hack. He’s using the uc to generate a PWM signal for a simple voltage step up circuit – the catch is that the controller has to start working before it can generate the signal. He came up with a nice little solution to this caveat – a push button start that gets things rolling once the coil charges up.
Thanks for the tips guys, keep em comin.
Not bad, but I think I’d have gone for the gusto and used a cap or RC between the coil and the FET gate… power on, cap is a short as it charges, which turns on the FET and bootstraps the chip… He’s right though… not bad.
Holy crap, I was just thinking about doing this the other day, except that I was planning to use a coin cell for the startup… Dam, guess I’ve been beaten to it.
hehe.. i had an idea for a miniature intelligent solar garden lamp with PIR proximity sensor, but the main sticking point was power.
charging a single high capacity NiMH AA cell is fairly easy. Also, a simple Schmitt trigger should be enough to generate the very brief pulse train to get things started when the light starts to fade.
as for low power, use a pic 12f675 in 32k mode, it draws under a milliamp when asleep.
-A
Thanks for the information.