Abstract: A voltage regulator for regulation both of AC and of DC voltages, is provided in a regulator module (30) which uses a repetitive switching signal (32) to control a switch (36) allowing current to be supplied to a reservoir capacitor (42) by supply from an unregulated rail (18). The module contains a dual inductor (44, 46, 48) having first (44) and second (46) identical windings and a common core. A current pass capacitor (43) is also provided. When the switch (36) is closed, the first winding (44) delivers current to the reservoir capacitor. When the switch (36) is open, both the second (44) and the first (46) windings deliver current to the reservoir capacitor (42). The apparatus can support balanced operation, where pairs of switches are operated alternately and oppositely. The switching signal (32) can be suitably voltage restored to provide a signal suitable to control and operates switches (36). Different configurations of transistor switches (36) and diodes (38) are shown.

Abstract: The invention provides a plug (100) which is adapted to be connected to a cable, such as an Ethernet cable, the plug (100) having a generally rectangular cross section and being dimensioned and arranged to be received by an aperture in a socket. On opposite lateral faces of the plug a region, or layer, of conductive material (24, 26) is provided for the transmission of electrical current to/from the cable. Use of the invention therefore permits cabling that has conventionally been used to supply data to also supply power, typically in excess of 200 Watts or so. Such amounts of power are sufficient for operating most equipment that also requires a data connection.

Abstract: The present invention relates to a motor controller and related method. The invention is particularly well suited for use with an alternating current (AC) induction motor. Previously motor controllers did not take into account the combined effect a control circuit and controlled motor, had upon a mains supply and more particularly their separate and combined effect upon the power factor of an alternating current. The invention solves this problem by providing a motor controller which modifies an input current to an alternating current (AC) motor. The motor controller comprises: a power input rectifier; a low voltage power supply; a variable output voltage circuit for adjusting a drive output voltage circuit; and a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit.

Abstract: Speed of a motor, generator or alternator, more particularly the speed of an alternating current (AC) induction motor is determined. Problems associated with previous devices are overcome by providing a speed monitoring device that is readily retrofitted to an existing motor. A test signal is superimposed onto an input voltage, which voltage in use is applied to at least one winding of the stator of a motor (the test signal is at a frequency substantially equal to the rotor frequency). The test signal frequency is varied so that it varies from a minimum frequency to a maximum frequency. A current monitor monitors a resultant current, in the at least one stator winding. and deriving from the resultant current is a signal indicative of the rotor frequency.

Abstract: A voltage regulator for regulation both of AC and of DC voltages, is provided in a regulator module (30) which uses a repetitive switching signal (32) to control a switch (36) allowing current to be supplied to a reservoir capacitor (42) by supply from an unregulated rail (18). The module contains a dual inductor (44, 46, 48) having first (44) and second (46) identical windings and a common core. A current pass capacitor (43) is also provided. When the switch (36) is closed, the first winding (44) delivers current to the reservoir capacitor. When the switch (36) is open, both the second (44) and the first (46) windings deliver current to the reservoir capacitor (42). The apparatus can support balanced operation, where pairs of switches are operated alternately and oppositely. The switching signal (32) can be suitably voltage restored to provide a signal suitable to control and operates switches (36). Different configurations of transistor switches (36) and diodes (38) are shown.

Abstract: The invention provides a plug (100) which is adapted to be connected to a cable, such as an Ethernet cable, the plug (100) having a generally rectangular cross section and being dimensioned and arranged to be received by an aperture in a socket. On opposite lateral faces of the plug a region, or layer, of conductive material (24, 26) is provided for the transmission of electrical current to/from the cable. Use of the invention therefore permits cabling that has conventionally been used to supply data to also supply power, typically in excess of 200 Watts or so. Such amounts of power are sufficient for operating most equipment that also requires a data connection.

Abstract: A circuit is provided for providing a drive signal. The circuit comprises a live input and a neutral input, an output for providing a drive signal, a master logic gate. The first output is connected to the master logic gate output. A dc signal is connected to the input of the master logic gate so that the output of the master logic gate changes when the state of the input changes. A shunt is connected to the live input and is capable of being switched into and out of the circuit in response to the live input voltage changing from positive to negative with respect to the neutral input voltage and vice versa. The shunt is also arranged to provide a short circuit for the dc signal to bypass the input of the master logic gate.

Abstract: A switching regulator for regulating an ac signal, and method of supplying power thereto wherein the regulator includes a positive half cycle part and a negative half-cycle part arranged to regulate the respective parts of an input ac signal. Each half-cycle part includes a modulating transistor, having an associated modulator diode, and a clamping diode arranged to protect the modulating transistor from reverse-bias voltages and having an associated clamp switch. The regulator further has a first switching controller operable to cause the modulating transistors to switch and a second, separate switching controller operable to cause the clamp switches to switch.

Abstract: The present invention relates to an apparatus and method for determining the speed of a motor, generator or alternator, more particularly for determining the speed of an alternating current (AC) induction motor. The invention overcomes problems associated with previous devices by providing a speed monitoring device that is readily retrofitted to an existing motor an comprises: a means for superimposing a test signal onto an input voltage, which voltage in use is applied to at least one winding of the stator of a motor (the test signal is at a frequency substantially equal to the rotor frequency); a means for varying the frequency of the test signal so that it varies from a minimum frequency to a maximum frequency; and a current monitor for monitoring a resultant current, in said at least one stator winding; and deriving from said resultant current a signal indicative of the rotor frequency.

Abstract: The present invention relates to a motor controller and related method. The invention is particularly well suited for use with an alternating current (AC) induction motor. Previously motor controllers did not take into account the combined effect a control circuit and controlled motor, had upon a mains supply and more particularly their separate and combined effect upon the power factor of an alternating current. The invention solves this problem by providing a motor controller which modifies an input current to an alternating current (AC) motor. The motor controller comprises: a power input rectifier; a low voltage power supply; a variable output voltage circuit for adjusting a drive output voltage circuit; and a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit.

Abstract: A circuit is provided for providing a drive signal. The circuit comprises a live input and a neutral input, an output for providing a drive signal, a master logic gate. The first output is connected to the master logic gate output. A dc signal is connected to the input of the master logic gate so that the output of the master logic gate changes when the state of the input changes. A shunt is connected to the live input and is capable of being switched into and out of the circuit in response to the live input voltage changing from positive to negative with respect to the neutral input voltage and vice versa. The shunt is also arranged to provide a short circuit for the dc signal to bypass the input of the master logic gate.

Abstract: A switching regulator and method of regulating an ac input signal to provide an ac output signal, receiving the ac input signal, generating a reference signal, detecting the points when the ac input signal is zero and synchronising the reference signal to these points, performing a subtraction between the reference and ac input signals to obtain an error signal, dividing the error signal by the reference signal to obtain a fractional error, and producing a regulated ac output signal by modulating the ac input signal to correct for the fractional error. The switching regulator uses a modulating transistor and clamping diode for each half-cycle of the input signal.

Abstract: A switching regulator for regulating an ac signal, and method of supplying power thereto are provided. The regulator includes a positive half cycle part and a negative half-cycle part arranged to regulate the respective parts of an input ac signal. Each half-cycle part comprises a modulating transistor, having an associated modulator diode, and a clamping diode arranged to protect the modulating transistor from reverse-bias voltages and having an associated clamp switch. The regulator further provides a first switching controller operable to cause the modulating transistors to switch and a second, separate switching controller operable to cause the clamp switches to switch.