Re: [CAD_CAM_EDM_DRO] Re: Pixie error connection

Tom , Keith,
I believe Keith is using the Sound Logic breakout boad.
So unless I am not understanding what you are trying to do This is what I would do.
Ehe Estop terminals on the breakout board is the coil of a 5v relay that needs to be held on ( open gives ESTOP condition ), so all he really needs
is the ULN2803 to turn the relay on. The ULN2803 has the diode for the coil built in. It requires no external power.
The 5k pull up is more that enough to drive the chip.
Keith, I will send you a drawing as to how to wire it up.
Jim

On 7/16/2007 1:26:30 AM, Tom Hubin (thubin@...) wrote:
> Hello Keith,
> Hello Keith,
>
> I looked at the Pixie specs at
> http://www.skyko.com/datasheets/SKY-P100.pdf . The paragraph on errors
> says that the error signal is pulled up to +5v with a 5kohm resistor. It
> does not mention current specifically but I can make some good guesses.
>
> A 5kohm resistor to +5v can source 1ma.
>
> The spec says that multiple Pixie errors can be wired together. This
> means that the open collector at any one of the error pins must be able
> to sink the total current from all of the error pullup resistors. I
> don't know how many Pixie boards are permitted but I would guess that a
> six axis machine is not out of the question. That would mean that the
> open collector should sink at least 6ma.
>
> As for the relay, I only found data on the Dayton 5Z950 solid state
> relay at the Grainger website. Is that a Grainger house brand?
>
> The Grainger spec gives voltage range for the control input but gives no
> info on control current or resistance. So I have no idea what current is
> needed to activate the relay. Could be a couple of ma or could be 100ma.
> Gotta get the info from the vendor or the manufacturer or you need to
> test it yourself.
>

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