forum.cncdrive.com

that looks really nice- would have saved me a lot of wiring headache on my last big machine! that too has just started throwing external estop called when my head up solenoid switches off. - will be adding a diode/cap to it today hoping to cure it. strange as its been running fine for 18 months now

Maybe electrolit capacitors drying out if it was running fine for 18months and just started having this issue.

So would this snubber work for something like solenoid noise?
http://www.newark.com/red-lion/snub0000 ... dp/05R0282

Could I put it at the solenoid or would it need to be at the board?

I know I'm paying a premium for connivance but I like that it's in a sealed package. And if I could slap it on my pneumatic valves it would be good insurance.

I'm using these across the 24V coils on my contactors. They might work with the solenoids.

https://www.amazon.com/gp/product/B00W1 ... UTF8&psc=1

One part of the problem with solenoids is the back emf generated by the coil when switching, the parallel diode will give a solution for that.
The other part is the switching transient and for that is what I advice a small ceramic capacitor, e.g. 100nF or a few hundred nanofarads across the solenoid coil,
because that will slow down the dV/dt, so the transient will be not that sharp.
A snubber could be also used or it could be used in addition, but it requires proper selection / sizing to the coil and switching parameters and for a small power part like this it is easier to just install a capacitor, because it has a low charge, so it causes no harm to the switching transistor or mosfet,
An incorrectly sized snubber will have zero or small effect on the frequency domain of the switching noise.

Please humor the Luddite:)

Would this capacitor: https://www.amazon.com/Ceramic-Capacito ... nF+ceramic
And this diode suggested by Gerry https://www.amazon.com/gp/product/B00W1 ... UTF8&psc=1
Do the job for 12v and 24v coils?

Thanks
Derek

If you're asking me, I'm not smart enough to know.

My choice of diode's was based on Automation Direct info on the contactors I'm using.

The in4007 is a great diode for back emf and will serve your needs well they are general purpose diodes with a very high (1000v) reverse voltage tollerance

Balazs, is it possible to publish the names for IO pins on the UC300ETH processor board and positions of the IDC26 connectors on the board?

Andrew,

You can probably work out the pins from this uc300 bob manual

http://cnc4pc.com/Tech_Docs/M44B-R1_USER%20MANUAL.pdf