SPST relays are the opposite of SPDT relays and are less common in the market. SPDT types are more widely used and have a wider range of applications. However, you can still find some SPST relays on the market. These devices are suitable for a variety of applications requiring small currents.

normally closed switch

The normally closed switch on the SPST relay controls the flow of current when the contacts are not actuated. In contrast, normally open switches allow current to flow when the contacts are actuated. Normally closed switches, also known as changeover contacts, have contacts in the "open" or "closed" position. When the switch is operated, the contacts will move from their closed position to their open position. This creates two distinct circuits.

Normally closed switches on SPST relays can be easily distinguished by their bidirectional contacts. When the excitation current is "OFF", the contacts of the normally closed switch are permanently closed. On the other hand, the contacts of a normally open switch open when current flows. In both cases, actuators are required to change the contact state.

Normally closed switches are used when circuits require high currents. This type of switch has two sets of terminals, one for each circuit. In the unipolar configuration, the switch has one common terminal, while the bipolar version uses two common terminals. One of the common terminals is connected to switch S1, while the other two are connected to the normally closed terminals of the circuit.

Normally open switch

Normally open switches on SPST relays are mechanical switches with two terminals. When the switch is activated, current flows from the normally open terminal to China automotive relay manufacturer the common terminal. The normally open switch on the SPST relay is more complicated because it is not a light switch. Normally open switches are used in a variety of applications including failover circuits and redundant signaling.

Normally open switches on SPST relays are similar to their opposite counterparts, but have alternating current (AC) circuits. When the switch is activated, current flows through its coil, causing the armature to move. This movement changes the state of the switch contacts. The maximum current rating of the contactor is higher than that of the normally open switch.

The normally open switch on the SPST relay is open when no current is flowing through the coil. In the inactive state, the NO normally open switch on the SPST relay disconnects power from the load. However, once current flows through the coil, the magnetic field closes the contacts and the load is energized. This is also known as a Type A relay.

Normally closed relay

A normally closed SPST relay is the opposite of a normally open SPST relay. In the open circuit state, this relay has no current flowing through its coil. In this inactive state, this type of relay disconnects power from the load. However, when current is applied to the coil, the resulting magnetic field closes the contacts, which turns on the load. These relays are also known as Form A relays.

Normally closed relays are used in many different applications. For example, some vehicles have safety features that shut down the vehicle if the driver is not in the seat. However, an immediate shutdown would be a lot of inconvenience, and a normally closed SPST relay would provide a delay for the driver to return to their seat. In addition, the G series time delay relays are hermetically sealed and can be used in flammable environments without the risk of sparking.

This type of relay has two circuits - one for the coil and one for the high current circuit. Coil resistance is usually around 80-60 W, indicating damage to the coil.

SPDT relay

SPDT relays are electronic switches used in electronic equipment. Its role is to connect a circuit with a smaller touch current to a larger circuit with a larger touch current. SPDT relays have 8 terminals: COM, COMMON, COIL, NO and NC terminals, and COIL. While the name SPST means that the switch has one pole and two throws, this is not always the case.

SPDT relays are commonly used in electronics. It is an electrical switch with five pins. Its contacts are normally normally closed (NC) and normally open (NO). The NC contact is electrically isolated from the common contact and has no physical connection to the other two contacts.

SPDT relays work by using a low voltage to convert an electromagnet into a magnetic field. The yoke on the relay connects the moving contacts of the armature to the circuit tracks on the PCB. This way, when the circuit switch is pressed, the relay will turn on and off.