Which coil type is energized when the signal does not reach the coil and de-energized when it does reach the coil?

Which coil type is energized when the signal does not reach the coil and de-energized when it does reach the coil?

• A. Non-Latching Coil
• B. Set & Hold
• C. Inverse Non-Latching Coil
• D. Reset Coil

Answer: (C)

Think in terms of negative logic: the coil here is designed to be energized when no signal is present and to drop out when a signal arrives. An inverse non-latching coil follows the input with inverted behavior, so it turns on in the absence of control input and turns off as soon as the input appears. Because it’s non-latching, it does not hold its state after the input changes—the coil responds directly to the current signal. This contrasts with a regular non-latching coil, which energizes when the signal is present; a Set & Hold coil, which latches on after condition and requires an action to release; and a Reset coil, which is intended to reset when a signal is present.

Think in terms of negative logic: the coil here is designed to be energized when no signal is present and to drop out when a signal arrives. An inverse non-latching coil follows the input with inverted behavior, so it turns on in the absence of control input and turns off as soon as the input appears. Because it’s non-latching, it does not hold its state after the input changes—the coil responds directly to the current signal. This contrasts with a regular non-latching coil, which energizes when the signal is present; a Set & Hold coil, which latches on after condition and requires an action to release; and a Reset coil, which is intended to reset when a signal is present.