Dwayne said:
>What sensor are you using?  Why is it at 3V?  Is the only
>load going to be this 5V reed relay?  How much current
>does the relay draw?

>Can you do a simple ASCII sketch of your hall effect circuit?

>I see several easy solutions depending upon what you tell us.


I have the allegro 3209 which runs at 3V and although there are numoreous
hall sensors this is the only one working for me.  The hall needs to give
pulse on any magnet pole N or S and no signal when there is no magnet (I
think it is called omnipolar).  If I could find the same sensor running at
5V another problem would arise as I need to run this circuit from either a
3V or 5V supply.

The hall sensor is powered from 3V, the open drain output is connected to
the + side of the reed relay (of course the relay needs 5V and it does not
work with this setup), the - side of the relay goes to ground.  This is the
basic circuit.

Eventually what I am trying to accomplish is that convert the hall sensor
output to a reed relay output and be able to run the circuit from either 3V
or 5V without any jumpers etc.

Any ideas is appriciated,

Regards,

Omer

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.