AVR-Chat

Hi Again, Yeah, that reset circuit is correct, it LP filters the reset
line, but still allows it to reset quickly when VCC drops out. 

Ive had endless trouble driving electric motors through fets straight
from the output of my micro controllers, noise and spikes can get to
the uc through an output! Maybe you can use a Schmidt trigger on the
back end of an optocoupler to keep the edges going to your fet nice
and fast ? Youd have to use a high speed optocoupler if you want to
PWM the fet tho. 

I believe the Tiny2313 is pin-compatible, not sure about the Tiny26. 

Yeah, its amazing how much punishment some power fets will take! And
the amount of current some of the IRF fets can pass is truly amazing,
but it's critical to keep the turn-on and turn-off times as short as
possible, I usually drive mine with a totem-pole configuration to
overcome the gate-source capacitance and have it turn on / off very fast!

Keep us informed on your progress and findings! 

Cheers
Hein B
Auckland, New Zealand. 


--- In AVR-Chat@yahoogroups.com, "max.motor" <imeelmax@...> wrote:
>
> 
> Thanks Hein & Leon,
> 
> Yeh, I've used a simple 78L05. It might be to slow. Have you got a
> partnr. of a quick version? Or would a suppressor be enough.
> 
>   I think swapping the 90s for a Tiny would be the easyest thing to do.
> Aren't both ones (Tiny26 & -2313) pin compatible with the 90s version?
> 
> About the reset circuit, would it be like this?
> 
> +                      -
> |           o--Reset   |
> |----|<|----|   100n   |
> |---[4k7]---|----||----|
> |                      |
> 
> The input signals are already opto coupled. The output signals aren't
> and that would be my next step. I wasn't for sure if it would give a
> sharp signal. as soon a power FET has to dissipate it'll get very very
> hot. I've got a To220 with a melted backside. (Yep, It's still alive)
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>