Re: [avr-chat] AVR on 1 AA bat with just 1 L and 1 C

[Dmitry K.]

On Thursday 24 March 2005 07:45, address@hidden wrote:
...
> 1) AVR grounds 'port pin', current flows via coil
>
> 2) AVR leaves 'port pin' floating, current still flows via coil and
> now it charges the cap via internal over-voltage protective diode on
> the pin
>
> Did I miss something?
>
> Well, how to switch it on... Maybe a pushbutton between port pin and
> gnd :-) ?  Not a big offense in a perverted design like this one...

This is very beautiful.

Bootstrap without active elements, may be:

Two aluminium capacitors and double switch:

  Off:  C1- ------------ Gnd
        C1+ -- switch -- Cell+
        C2- -- switch -- Gnd
        C2+ ------------ Vcc

  Insert cell:
        C1 == 1.5V
        C2 == aprox. 1.0V

  On:   C1- ------------ Gnd
        C1+ -- switch -- C2-
        C2- -- switch -- C1+
        C2+ ------------ Vcc

  Now:  C1 and C2 in serial with initial voltage aprox. 2.5V
        for power before program start. (I hope, 1.8V is minimum
        with this chip?).

Regards.