Which type of switch is recommended for a circuit that must be manually held ON?

The recommended type of switch for a circuit that must be manually held ON is a single-pole, single-throw (SPST), two-position normally open (NO) switch. This type of switch is designed to complete the circuit when it is activated, allowing current to flow through to the connected load. Its two-position functionality means it can be either in the ON position or the OFF position.

When the switch is pressed or otherwise engaged, it holds the circuit in the ON state until it is manually released, making it ideal for applications where a temporary connection is required. This is particularly useful in scenarios where the user needs to maintain control over the circuit's operation, such as starting an engine or activating a particular function within the aircraft.

The other types of switches do not offer the same tailored functionality for this application. A single-pole, double-throw (SPDT) switch might allow for switching between two different circuits rather than just ON or OFF, which isn't necessary for a simple hold feature. A double-pole, single-throw (DPST) switch is more complex with two circuits that are either both connected or disconnected simultaneously, which is also unnecessary for a straightforward manual hold. Lastly, the single-pole, single-throw (SP