Abstract: An electrical circuit, controlled by an electromagnetic relay, comprising an electromagnetic relay having relay contacts for controlling current flow to a load in use, and a relay winding which, when energized, causes closure of said relay contacts. First manually operable switch means is provided for energizing said relay winding, and a feed connection is provided from said relay contacts to said relay winding whereby said winding is energized while said contacts are closed. A second manually operable switch means for short circuiting said relay winding is provided to permit said relay contacts to open. An overload protection winding is physically associated with the relay winding and connected in series with the contacts, said overload protection winding being such that when the current flowing therethrough exceeds a predetermined value the electromagnetic effect generated opposes the electromagnetic effect of the relay winding to a sufficient extent to permit said relay contacts to open.

Abstract: An electrical switch wherein the movable contact is resiliently biassed out of engagement with the fixed contact and is movable into engagement with the fixed contact by a rotatable cam. The cam is rotatable by a manual operating member and there is provided an electromagnetic arrangement for moving the cam in the direction of its rotational axis relative to the moving contact. The cam can be rotated in one direction from a rest position to close the movable contact to the fixed contact and can be rotated in the opposite direction to disengage the movable contact from the fixed contact. The cam is also movable axially by the electromagnetic means without reverse rotation of the operating member so as to permit the movable contact to return to its rest position. The cam carries first and second cam forms each of which is capable upon rotation of the cam, of moving the movable contact to engage its fixed contact.

Abstract: An electrical switch having first and second sets of contacts and an operating member which is associated with both sets of contacts such that both sets of contacts can be moved from one of their operative states to the other operative state by a single movement of the operating member. A first electromagnetic arrangement is provided whereby the first set of contacts can be returned from the closed state to the open state by the application to the first electromagnetic arrangement of an electrical signal, and there is a second electromagnetic arrangement whereby the second set of contacts can be returned from the closed state to the open state by the application to the second electromagnetic arrangement of the electrical signal. The switch is so arranged that the first set of electrical contacts is returned by the electrical signal to its open state in advance of the return of the second set of electrical contacts to its open state.

Abstract: A switch including an input terminal which is electrically connected in use to one pole of an electric storage battery, an output terminal and a movable contact movable between an inoperative position wherein the movable contact is isolated from at least one of the input and output terminals and a operative position wherein the movable contact electrically interconnects the input and output terminals. An electro-magnet winding is provided which, when energized prevents movement of the movable contact to the operative position and the winding and a semi-conductor diode are connected in series between the input terminal and a further terminal which in use is connected to the other pole of the battery.

Abstract: A solenoid switch, particularly but not exclusively for use in a starter motor supply circuit includes a solenoid coil and at least one fixed contact. An armature is movable relative to the coil in response to energisation of the coil and carries a movable contact. The movable contact is urged by resilient means to a rest position relative to the armature and a member is coupled to the armature through said resilient means for movement with the armature in a direction to engage the movable contact with the fixed contact. The switch further includes a delay unit for slowing movement of the member in the contact engaging direction, the arrangement being such that in use when the movable contact engages the fixed contact the armature moves relative to the member and the movable contact compressing said resilient means and thereby increasing the pressure between the contacts.