RF3 + Duet2 + Electromagnet

  • To be on the safe side, I would need a second opinion before I spend more thought on it!

    Can a "Linear Solenoids Cylinder Solenoids" (e.g. https://www.red-magnetics.com/en/product-groups/linear-solenoids/cylinder-solenoids/its-lz-1335-z/) be controlled with the Duet?
    By using "exp.heater3 and exp.heater4" from Expansion header directly without using an expansion board.

    With RF3 this should be possible, right?

    Thank you for your answers and advice!

  • No. You could use a fan output if these are 8 watts, make sure you have a 1.02 or later PCB or you will need a flyback diode.

  • Pins in the expansion header can drive TINY amounts of current, at 3.3V. A few milli-amps at most.

    Those things need 6V 12V or 24v and can draw 6+ Amps under various circumstances. That is 6000 milli amps. Even attempting it would damage the pin.

    You CAN drive an SSR (solid state relay) from an expansion pin, and drive the solenoid from that. Or various transistor drive circuits.

  • Many thanks to you, I'm a little smarter now.

    So it would go to the fan output? Have Duet2 V1.03.

    Would 5V also go to the expansion header since there is more choice with 5V?

  • I am not 100% certain either way, but I believe those things might outdraw a Fan output in many cases. Since the result of a sustained over-current is a blown MOSFET on the DUET board, I wouldn't even try it.

    Expansion pin, or fan, to SSR. SSR to Solenoid.

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