Re: A LEGO double-throw switch?

On Mon, August 22, 2005 4:38 pm, Kyle McDonald wrote:
> Steve Hassenplug wrote:
>
>>When the switches are in the same position, the belt will not move.  When in
>>opposite positions, it will run (some direction)
>>
>>Two problems:
>>1) Half the time, the motor will run backwards (can be fixed using diodes)
>>
>>
> Since turning the 9V wire connectors 90 degrees reverse the polarity,
> can't you play with how the wires are connected to the switches to
> re-reverse the polarity on one wire?

No, because it's only wrong half the time.

HOWEVER, now that I think about it, you could mechanically connect two polarity
switches together at the end with the motor.  Then, instead of connecting one wire
from each of the polarity switches to the motor, you connect them to the third
polarity switch, and connect that directly to the motor, and let the switch reverse
polarity.  I don't think it matters which end it's on.

Now, to figure out that pesky dead-zone problem...

>2) The "dead" zone where a crate can turn "off" switch 2, but not move it all the
>way to the "reverse" direction.
>

That may be solved, depending on how the crates get unloaded from the belt.  Heck,
considering the motors will be "floating/coasting" the crate and belt may be able to
coast to the next stop, at which point it will go into "Brake" mode.

Steve