Power Relays, Over 2 Amps

2903680 Application Field and Working Principle

Power relays, typically expressible as TP or SPST type relays, are typically employed as electromechanical switches that aids in the movement of electricity, from one circuit to another – often bridging the two. The application field of power relays are far-reaching, being prevalent in almost every electrical and electronic device currently available. This being said, the electromechanical switch behavior of the 2903680 power relay, or any other power relay, is determined by a handful of fundamental elements.

The general operating principle of the 2903680 power relay, and of power relays as a whole, involves the creation of an electrical field in the “coil” element. This field is created by supplying current through the coil, arising from the previous circuit. This current causes a magnetic field to form in the coil, which in turn causes a flux to permeate through the core. This flux, being comprised of electrons, is stationary in the ferric core until the current is interrupted.

The interruption of the current to the coil reverses the movement of electrons, and resets the flux from a stationary state. The coil at this point is immediately placed in a low current state, and can no longer cause a magnetic field to form. This event is recognized as the reset state of the power relay, and causes the switch to close, and the power to be moved from one circuit to another.

The resetting of a power relay involves the breaking of the magnetic field, which typically requires a “pickup voltage” component. This is explained by the fact that a “pickup voltage” must be applied to the coil, to cause a magnetic field large enough to create enough flux to open the contacts. The contacts of a power relay provide a mechanical path for the motors and controls to receive their commands through.

The last general principle of the 2903680 power relay, and of all power relays for that matter, involves the inherent “plunger” movement that completes the reset process. When the magnetic field is broken, the flux is corrupted, and the plunger is forced away from the core. This motion causes the contacts of the power relay to separate, restoring the power relay to its initial state.

Power relays, such as the 2903680, are widely used in most motor-controlled and pneumatically-driven circuits, due to their ability to start and stop an electrical path to a given device. The application field of power relays is ever-expanding, and its working principle remains relatively constant.