A tester for a relay comprises an enclosure, a testing circuit that includes a controller, electronic switch components, a power source, indicator LEDs, a test start switch, a relay selector switch, and five electric leads each connected with one terminal of the relay. With the relay selector switch toggled to indicate the type of relay being tested, with power supplied to each lead, and with the test start switch actuated, the controller sets each lead to ground, in turn, and then count the number of other leads that are grounded as a result. The controller then illuminates the at least one indicator to indicate either the passing relay test or the failed relay test based on the counts measured. Once the leads connected to the relay coil are identified, cyclic testing of the relay can be performed.

The present disclosure discloses a high-voltage DC relay with an auxiliary contact. The high-voltage DC relay includes a cover, a main contact leading-out terminal, a pushing rod assembly, a main movable contact piece, an auxiliary contact leading-out terminal and an auxiliary movable contact piece. The main contact leading-out terminal and the auxiliary contact leading-out terminal are respectively fixed on a top wall of the cover and their bottom ends respectively extend into a cavity of the cover. The main movable contact piece and the auxiliary movable contact piece are respectively matched with corresponding bottom ends of the main contact leading-out terminal and the auxiliary contact leading-out terminal. Two auxiliary contact leading-out terminals are arranged on both sides of a connecting line between two main contact leading-out terminals, and the auxiliary movable contact piece is also connected with a plastic body.

The present disclosure discloses a high-voltage DC relay with an auxiliary contact. The high-voltage DC relay includes a cover, a main contact leading-out terminal, a pushing rod assembly, a main movable contact piece, an auxiliary contact leading-out terminal and an auxiliary movable contact piece. The main contact leading-out terminal and the auxiliary contact leading-out terminal are respectively fixed on a top wall of the cover and their bottom ends respectively extend into a cavity of the cover. The main movable contact piece and the auxiliary movable contact piece are respectively matched with corresponding bottom ends of the main contact leading-out terminal and the auxiliary contact leading-out terminal. Two auxiliary contact leading-out terminals are arranged on both sides of a connecting line between two main contact leading-out terminals, and the auxiliary movable contact piece is also connected with a plastic body.

An electromagnetic trip unit, wherein: the electromagnetic trip unit includes a movable core, an upper static core and a lower static core; the movable core can move relative to the upper static core and the lower static core in the upper static core and the lower static core; a movable core body end of a movable core body of the movable core faces and approaches the lower static core end of the lower static core, when the electromagnetic trip unit is not released, a first magnetic field air gap is formed between the movable core body end and the lower static core end; the movable core body of the movable core is also provided with a movable core body step, when the electromagnetic trip unit is not released, a second magnetic field air gap is formed between the movable core body step and the lower static core end.

An electromagnetic trip unit, wherein: the electromagnetic trip unit includes a movable core, an upper static core and a lower static core; the movable core can move relative to the upper static core and the lower static core in the upper static core and the lower static core; a movable core body end of a movable core body of the movable core faces and approaches the lower static core end of the lower static core, when the electromagnetic trip unit is not released, a first magnetic field air gap is formed between the movable core body end and the lower static core end; the movable core body of the movable core is also provided with a movable core body step, when the electromagnetic trip unit is not released, a second magnetic field air gap is formed between the movable core body step and the lower static core end.

An electrical switching element includes a housing, an armature moved by a coil arrangement, a contact arrangement switchable by the armature into at least two switching statuses, and a magnetic field sensor outputting a magnetic field-dependent switching signal representing the switching statuses. The armature, the contact arrangement, and the magnetic field sensor are arranged in the housing. The armature is arranged between the contact arrangement and the magnetic field sensor.

An electrical switching element includes a housing, an armature moved by a coil arrangement, a contact arrangement switchable by the armature into at least two switching statuses, and a magnetic field sensor outputting a magnetic field-dependent switching signal representing the switching statuses. The armature, the contact arrangement, and the magnetic field sensor are arranged in the housing. The armature is arranged between the contact arrangement and the magnetic field sensor.

A method of controlling an electromagnetic relay includes supplying a first voltage to an exciting coil to bring a movable terminal into contact with a fixing terminal; causing a coupling state determination unit to determine that a coupling failure is detected in a case where the movable terminal is not brought into contact with the fixing terminal and the electromagnetic relay is not turned on despite the supplying the first voltage to the exciting coil; and supplying a second voltage higher than the first voltage from a booster circuit to the exciting coil in a case where the coupling state determination unit determines that the coupling failure is detected. The second voltage is generated by boosting the first voltage by the booster circuit.

A method of controlling an electromagnetic relay includes supplying a first voltage to an exciting coil to bring a movable terminal into contact with a fixing terminal; causing a coupling state determination unit to determine that a coupling failure is detected in a case where the movable terminal is not brought into contact with the fixing terminal and the electromagnetic relay is not turned on despite the supplying the first voltage to the exciting coil; and supplying a second voltage higher than the first voltage from a booster circuit to the exciting coil in a case where the coupling state determination unit determines that the coupling failure is detected. The second voltage is generated by boosting the first voltage by the booster circuit.

A contactor includes first and second fixed contacts coupled to a housing having mating ends located in the cavity. The contactor includes a movable contact movable within the cavity between a mated position and an unmated position. The movable contact engages the second mating end in the mated position and is separated from the second fixed contact in the unmated position. The contactor includes a coil assembly in the cavity operated to move the movable contact. The contactor includes a magnetic shroud coupled to at least one of the movable contact and the second fixed contact to provide a magnetic holding force to hold the movable contact relative to the second fixed contact in the mated position.