Re: Advice needed - Mariss' e-stop circuit

Hi Tom,

if you are looking for an enable/disable for the circuit, the
momentary listed as the e-stop is the on/off switch. All it does is
open one leg of the DPDT relay coil.

there is no other effect in software unless you add something.

As it is listed, the on momentary and off can be s single on-off-on
double pole momentary.

you can put in as many stops swithces as you like, drive them from
software or end switches or whatever.

if you use one as part of a total e-stop, that switch also needs to
be connected to the pc. you can do that by using a 3pdt relay and
the 3rd being a software link, or a second relay, or even a dp-
momentary.

also, the e-stop is not required to be a momentary. as long as it is
open the units will not run. so it could be a hard off.

Dave






--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Tom Murray
<thomasm923@a...>" <thomasm923@a...> wrote:

> I am building a power supply using Mariss' servodrive e-stop

circuit,

> which is in the files section of this group.
>
> http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/A%20Servo%20E-
> Stop%20Circuit.pdf
>
> I would like to add an on-off switch to this circuit. As is, the

only

> way to turn this circuit off is by hitting the e-stop switch or
> unplugging it. I am wondering if a momentary-off-momentary switch
> could be used? Since both sides of this switch are normally open,

the

> side that serves to interrupt the current to the relay's coil would
> need additional components. Would a switching transistor work here?
> If so, how should the circuitry it be set up?
>
> I realize that I could easily use two switches on the power

supply's

> front panel; a SPST momentary NC switch and a SPST momentary NO
> switch, but I am curious about the above mentioned option.
>
> Any ideas?
>
> Thanks,
> Tom Murray