What type of circuit is formed when a relay continues to energize itself after a momentary input is removed?

A seal-in circuit, also known as a latching circuit, is designed to maintain itself in an energized state even after the initial input signal is removed. This self-sustaining operation is achieved through feedback from the relay contacts back into the control circuit. When the relay is activated, it closes its own contact, which allows current to continue flowing even after the external momentary input is removed. This mechanism is widely used in applications where it is necessary for a device to remain active without continuous input, such as in push-button controls for lights or other outputs.

In contrast, a momentary circuit does not sustain its state after the input is removed, and a latch circuit is often used interchangeably with a seal-in circuit but is a more general term that can apply to different types of latching mechanisms. A timing circuit typically involves delay functions and is not concerned with maintaining an energized state after an input has ceased. Thus, the seal-in circuit is the most accurate description of the scenario where a relay continues to energize itself after the momentary input is removed.