Author Topic: is output of MC050-120 protected ??  (Read 7029 times)

Offline Pankaj

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is output of MC050-120 protected ??
« on: August 23, 2017, 09:48:28 AM »
Hi ,

Is output pins on MC050-120 protected ? I mean can I drive relay directly without diode in parallel.


Offline FluidPowerTom

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Re: is output of MC050-120 protected ??
« Reply #1 on: August 23, 2017, 05:26:12 PM »
I've never needed to add a diode in parallel to any relay, valve, or anything else that I drive with a PLUS1 controller.  Granted most 'bang-bang' solenoid valve relays have a diode in parallel inside the valve coil.  Either way, all outputs on the PLUS1 controller are designed to source at least 3A directly, so unlike an industrial PLC there's no need for a relay and diode to be used when controlling a solenoid valve.
Controls Engineer
Hydra-Power Systems

Offline niteRider

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Re: is output of MC050-120 protected ??
« Reply #2 on: August 23, 2017, 07:19:26 PM »
only thing you really have to watch out for is to design your system such that there is never any chance of a power source being present on a output pin when the controller is powered off.  Voltage on an output pin with the controller powered down will blow the output pin, and it will become stuck in an ON state (i.e., a short to VCC).

Like Tom says, the pins are protected from transients and shorts... you sometimes have to add logic on the outputs to watch out for Overloads on the pins if your solenoids are not equipped with a flyback diode/MOV.