Re: [CAD_CAM_EDM_DRO] Re: Spindle Relay Question

volitan712003 wrote:

>Let me be more clear. The drive will accept a 10 volt analog signal to
>control the speed, so controlling the spindle via computer is no
>problem.
>
>

I'm curious how you are controlling it? Are you just giving it 5v to
run it at a single speed, or do you have fancier interface?

>The drive will not reverse the motor. The only way to do that is swap
>the 2 power wires going to it (the motor). That's why I'm after (I
>think) a DPDT relay. Just can't find one. Or else if anyone has any
>better idea...
>
>

I assume the brushless motor controller is smart enough to figure out
how fast the motor is running an handles keeping it at the correct speed?

It sounds to me like all you need are some beefy MOSFETs to make a
standard h-bridge, and maybe a bit of logic to set the input control
lines, depending on what kind of interface you need. I know the solid
state relays are pretty popular for things like this, but I think the
discrete MOSFETs will be more reliable. Set it up right and they'll
take a heck of a beating. I suppose your comfort level with building
simple circuits would decide whether or not it would be realistic to set
up something like that.

Dave