Abstract: A toroidal core for a toroid, comprising at least two toroidal rings that are stacked co-axially one upon another. At least one of the two toroidal rings has a body including a gap that forms a break in one side of the body. The gap is present to avoid saturation of the core.

Abstract: A power supply module for use between an AC/DC power supply unit and an electrical power tool driven by an electric motor and powered by a rechargeable battery pack which has a normal operating voltage and a higher fully-charged terminal voltage. The module comprises an input connectable to the supply unit and an output connectable in parallel to the battery pack, and an operating circuitry for delivering DC power from the supply unit to the tool in parallel with the battery pack. The operating circuitry provides a DC operating voltage at the output of a value between the normal operating voltage and the fully-charged terminal voltage of the battery pack, and provides an output current limited to a predetermined value. The circuitry has a comparator for determining whether the output current is less than or has a tendency exceeding the predetermined value and then providing a corresponding control signal.

Abstract: A circuit breaker includes two movable contacts for electrical connection to a load and a power source, respectively, a movable contact holder holding the first contact, a first spring biassing the contact holder, and an actuator for moving the second contact into contact with the first contact. A locking frame locks the contact holder and, in turn, the first contact at a first position in the path of movement of the second contact, against the spring, for contact by the second contact. The locking frame pivots between a first locking position locking the contact holder in the first position and a second position releasing the contact holder from the first position. A second spring biasses the locking frame towards the second position. A solenoid holds the locking frame in the first position against the second spring. An electronic control circuit detects occurrence of a circuit fault and, in response to detecting a fault, disables the solenoid.

Abstract: An electrical switch comprising a casing and a rotor supported within the casing for rotation about an axis. The rotor has a first surface extending around the axis and a second surface extending transversely of the axis. A moving contact is mounted on the rotor for rotation therewith, which has first and second inter-connected parts adjacent the first and second rotor surfaces respectively. A plurality of fixed contacts is located laterally of the rotor for short-circuiting by the moving contact whereby the switch is closed. At least one of the fixed contacts has first and second inter-connected parts bearing resiliently against the first and second rotor surfaces respectively for contact with the corresponding fist and second moving contact parts according to the angular position of the rotor.

Abstract: An electrical switch assembly for controlling an electrical appliance, which assembly comprises first and second electrical elements. The first element is an on/off switch for initially switching on the appliance. The second element is a pressure-sensitive variable resistor for subsequently adjusting the operating condition of the appliance. The variable resistor comprises a first part having a resilient deformable and electrically conducting resistive surface, and a second part having a surface including two contacts and a resistive element connecting the two contacts. One of the parts is movable to press against the other part such that their surfaces bear against one another, thereby causing the resistive surface to deform against the surface of the second part over an area of contact and causing electrical connection between the resistive surface and element.

Abstract: A circuit breaker (100) for use between a load and a power source, comprising at least two movable contacts (212/222) for electrical connection to the load and power source respectively, a movable contact holder (220) holding the first contact (222), a first spring (224) biassing the contact holder (220) to move, and an actuator (210) arranged to move the second contact (212) into contact with the first contact (222). A locking frame (230) is arranged to lock the contact holder (220) and in turn the first contact (222) at a specific position into the path of movement of the second contact (212), against the action of the spring (224), for contact by the second contact (212). The locking frame (230) is supported for pivotal movement between a first position locking the contact holder (220) in said specific position and a second position releasing the contact holder (220) from said specific position. A second spring (238) biasses the locking frame (230) towards the second position.

Abstract: An electrical switch includes a body, three control terminals and a common terminal for external connection and a movable contact for establishing connection between the control terminals and the common terminal. The movable contact has one end acting as the common terminal and three opposite ends that pivot to connect to the control terminals, respectively. Each opposite end is pivotable between a first position in contact with the corresponding control terminal and a second position separated from the corresponding control terminal. A switching member is supported for pivoting the opposite ends of the movable contact to establish the connection. A single metal heat sink is located within the body for contact by the opposite ends of the movable contacts when the movable contacts are in the second positions.

Abstract: An electrical switch (100) comprising a body (110), three control terminals (121-123) and a common terminal (134) for external connection, and a movable contact (130) for establishing connection between the control terminals (121-123) and the common terminal (123). The movable contact (130) has one end (134) acting as the common terminal (134) and three opposite ends (131-133) pivotable to connect to the control terminals (121-123) respectively. Each opposite end (131/132/133) is pivotable between a first position in contact with the corresponding control terminal (121/122/123) and a second position off the corresponding control terminal (121/122/123). A switching member (140) is supported for pivoting the opposite ends (131-133) of the movable contact (130) to establish the said connection. A single metal heat sink (160) is located within the body (110) for contact by the opposite ends (131-133) when they are in the second positions.

Abstract: A device for sensing motor current for over-current protection in an electric power tool. The tool includes an electric motor supplied with electrical power via a live cable and incorporates over-current protection including a tripping circuit with a current sensor associated with the live cable. The device includes a toroid of the sensor and two cable segments connected in parallel to a section of the live cable such that the motor current will be distributed among the cable segments and live cable section in respective proportions. The toroid extends around one cable segment for sensing the respective proportion of the motor current.

Abstract: A power plug includes a plug body having opposite sides and an end, terminal prongs extending from the end of the plug body, and a built-in circuit breaker. The circuit breaker is operable between a normal condition enabling the power plug to connect a load to a power source and a tripped condition disconnecting the load upon the detection of a circuit fault. The circuit breaker includes at least two members at respective opposite sides of the plug body which are simultaneously movable between a first position corresponding to the normal condition and a second position corresponding to the tripped condition. The members provide an indication of the operating condition of the circuit breaker viewable on both sides of the plug body.

Abstract: A method and system for authenticating the identity of a user by an authority makes use of presenting biometric data for the user in a predetermined shared secret sequence. The method and system can be augmented by requesting an additional shared secret, such as a PIN or additional credentials, to establish multiple layers of authentication. Varying the layers of authentication results in greater or lesser security, and the accuracy for any given layer can be relaxed without compromising the integrity of the entire method.

Abstract: An electrical switch including a body, fixed and movable contacts in the body, a principal switching member supported by the body for movement between ON and OFF positions, and a subsidiary switching member supported by the principal switching member for movement in directions different from directions of movement of the principal switching member. The principal switching member has an inner part providing a switching profile to operate the movable contacts with respect to the fixed contacts for switching. The subsidiary switching member has an inner part positioned at the switching profile for changing the switching profile while the principal switching member is in the ON position. The switch may be used to control the operation of a hair dryer to provide, in particular, a COOL shot by operation of the subsidiary switching member.

Abstract: An on-off switch for an electric power hand tool such as an electric saw. The switch has a body, a switching mechanism within the body, and a spring-loaded trigger supported by the body for movement between a first position to turn on the switching mechanism and a second position to turn off the switching mechanism. The switch includes a movable locking device resiliently biased by a spring for locking the trigger in the second position against accidental switching on. The trigger and locking device include respective parts for abutment with each other to lock the trigger in the second position.

Abstract: An electrical rocker switch includes a body having at least two switch terminals, an internal switching mechanism for momentarily making or breaking an electrical connection between the terminals, an actuating knob on the body for operating the switching mechanism, a rocker supported on the body for pivotal movement between a first position depressing the actuating knob relative to the body and a second position releasing the actuating knob, and a resiliently biassed member for maintaining the rocker in the first and second positions.

Abstract: An electrical switch includes a body, pressure-actuated buttons, switch terminals having respective parts forming internal switches, cam sliders extending side-by-side between the buttons and the parts for movement by the buttons to turn on and off the internal switches. The buttons include a first button for turning off all but the first of the internal switches. The other buttons turn on the other internal switches. The first button incorporates a movable cam engageable with the sliders for momentarily turning on the first internal switch after the other internal switches have all been turned off.

Abstract: A circuit breaker comprising a switch for controlling the connection of a load to a power source, the switch having a fixed contact and a movable switch contact supported on a pivotable switching member and resiliently biased away from the fixed contact. The circuit breaker includes a solenoid having a first winding for initially moving the movable contact towards the fixed contact and a second winding for holding the movable contact against the fixed contact, a fault detection circuit adapted to detect a fault at the load and in response to disable the solenoid, and a reset switch for initially enabling energization of the first winding and when the movable contact is sufficiently close to or in contact with the fixed contact for subsequently enabling energization of the second winding. The reset switch is arranged to be operated by a part of the switching member by virtue of the movement of the movable contact in order to control energization of the windings.

Abstract: An electrical switch comprising a body having two switch terminals, a switching member having an a side and a window provided at the side. The switching member is supported by the body for pivotal movement between a first position in which the terminals are electrically interconnected and a second position in which the terminals are electrically disconnected. The switch includes an indicator supported behind and arranged for exposure through the window of the switching member to indicate the switching condition of the switch through relative movement between the switching member and the indicator. The indicator has a single surface to indicate said switching condition.