Which component is commonly used as the memory logic element in pneumatic control circuits?

Which component is commonly used as the memory logic element in pneumatic control circuits?

• A. Control relay
• B. Pneumatic cylinder
• C. Limit switch
• D. Pressure sensor

Answer: (A)

Memory in pneumatic control circuits is typically implemented with a control relay because its contacts can hold a state independent of the immediate input. Energizing the relay coil closes a contact that can create a self-holding path, keeping the coil energized even after the initial signal is removed. This latched condition stores the on/off state, which is exactly what a memory element needs in simple logic circuits. The other devices serve different roles: a pneumatic cylinder is the actuator that performs motion, a limit switch provides a position-based signal, and a pressure sensor monitors pressure. They don’t store a state to control subsequent actions in the same way a relay can.

Memory in pneumatic control circuits is typically implemented with a control relay because its contacts can hold a state independent of the immediate input. Energizing the relay coil closes a contact that can create a self-holding path, keeping the coil energized even after the initial signal is removed. This latched condition stores the on/off state, which is exactly what a memory element needs in simple logic circuits. The other devices serve different roles: a pneumatic cylinder is the actuator that performs motion, a limit switch provides a position-based signal, and a pressure sensor monitors pressure. They don’t store a state to control subsequent actions in the same way a relay can.