🔍 Key Concepts

• For a simple motor controller, think about how a PLC creates a "seal‑in" or "latching" circuit so the motor stays on after you release the start control. • Notice that Input A is in parallel with the Output contact, and Input B is in series ahead of the Output coil. • Recall the usual roles of start and stop pushbuttons in motor control: which is normally open and which is normally closed?

💭 Think About

• If the motor is supposed to keep running after you press a button and release it, which device (momentary or maintained) would you use for the initial start signal? • Which input in the diagram is more likely to be the stop device, based on being normally closed (slash through the contact) and placed in series with the coil? • Given that arrangement, what must Input A be so that once the output is energized, the parallel contact can hold the circuit in?

✅ Before You Answer

• Confirm which contact symbol in the figure is normally open (two parallel lines) versus normally closed (two lines with a diagonal slash). • Verify which device type is usual for a start push button versus a stop push button in basic motor control circuits. • Make sure your choice for Input A is consistent with a latching circuit: after you release the control, the motor should stay energized via the Output contact.