What is the difference between normally open and normally closed of KSD thermostat?

What is the difference between normally open and normally closed of KSD thermostat?

Different in usage:

1. When the main switch is closed, the auxiliary switch is also closed. This auxiliary switch is called a normally open contact. When the main switch is off, it also opens.

2. The auxiliary switch that is in the closed state when the main switch is off is called a normally closed contact. When the main switch is closed, it will open.

Refers to different:

1. Normally open contact: The contact of the relay when the coil is not energized.

2. Normally closed contact: the contact of the relay in the closed state when the coil is not energized.

The principle is different:

1. Normally open contact: Add a certain voltage to both ends of the coil, and a certain current will flow through the coil, which will produce electromagnetic effects. Under the action of electromagnetic force, the armature will overcome the pulling force of the return spring and attract to the iron core. , So as to drive the moving contact of the armature and the static contact (normally open contact) to attract.

2. Normally closed contact: When the coil is de-energized, the electromagnetic attraction will also disappear, and the armature will return to its original position under the reaction force of the spring, so that the moving contact is attracted to the original static contact (normally closed contact).