Abstract:
A mounting latch for mounting a device to a rail is provided. The mounting latch comprises: a moveable actuator having a profile; a latch mechanism comprising first and second opposed rail engaging members, at least one of the members having a face for causing the member to yield against a bias source when the latch mechanism is engaging with the rail; and a follower enabling the at least one member to follow a rotational movement of the actuator such that movement of the actuator in a first direction causes the at least one member to become unlatched from the rail.
Abstract:
There is described a method (20) of cooling a device generating heat. The method includes (21) monitoring a temperature associated with the device. The method also includes (25) automatically operating a cooling means at a first rate if the monitored temperature rises above a first temperature threshold. The method also includes (26) automatically operating the cooling means at a second increased rate if the monitored temperature rises above a second temperature threshold. There is also described a system (10) for cooling a device (16) generating heat. The system (10) comprises means (18) for monitoring a temperature associated with the device (10), cooling means (14), and a controller (12) for operating the cooling means (14) at various rates. The controller (12) is arranged to automatically operate the cooling means (14) at a first rate if the temperature rises above a first temperature threshold. The controller (12) is further arranged to automatically operate the cooling means (14) at a second increased rate if the temperature rises above a second temperature threshold. According to the invention, the point at which the monitored temperature reaches the second threshold may be delayed by operating the cooling means at a first rate prior to operating the cooling means at an increased second rate. In applications in which short periods of relatively high heat generation are experienced, the invention may delay the point at which the cooling means needs to be operated at a high level, reducing the overall noise generation of the cooling means.
Abstract:
A circuit for an electrical load comprises a passive transformer, the secondary of which is connected to power cells for each phase according to the transformer tappings. Each power cell comprises a low cost but efficient power factor correction circuit to produce lower harmonics on the transformer.
Abstract:
An inverter circuit comprises an inverter which can be configurable for controlling the supply of mains current from a grid to an electric machine in a start-up mode whereby the machine drives the prime mover for initialisation. Thereafter the same inverter is reconfigurable as part of the circuit to supply reactive power to the grid when the machine is running as a generator powered by the prime mover.
Abstract:
A desaturation detection circuit for use between the desaturation detection input of an optocoupler and the output of a power switching device, the desaturation detection circuit comprising: a threshold setting element having an input and an output, the input for connection to the output of a power switching device via one or more diode(s), the threshold setting element being arranged to set a threshold voltage at the input at which the threshold setting element will provide an output at the output of the threshold setting element when the input voltage is exceeded, and a detector having an input connected to the output of the threshold setting element and an output connectable to a desaturation detection input of an optocoupler, the detector being arranged to detect an output at the output of the threshold setting element and in response to provide a control signal at the output of the detector for the desaturation detection input to trigger a desaturation routine in the optocoupler.
Abstract:
A circuit for monitoring the operation of an electric motor comprises means for deriving a motor signal indicative of a relatively low frequency characteristic of the motor commutation current (for example the back EMF ripple) by rejecting the high frequency components which are mainly the result of the commutation events. The circuit also includes means for producing a pulse from the low frequency characteristic which has a duration related to the motor speed.
Abstract:
A method and apparatus to monitor the condition of an apparatus (e.g a variable speed drive), the apparatus comprising: a processor, a plurality of devices and a plurality of temperature sensors, each sensor associated with a device, the processor being arranged in use to: determine, for each of a plurality of sensors, the temperature of the associated device based on the temperature sensed by the sensor and the mode of operation of the device; compare the determined temperatures for each device with stored data relating to the mode of operation of the apparatus; and based on the comparison determine whether the apparatus is operating as expected in the mode of operation.
Abstract:
A method of controlling a current flowing through a component of a drive comprising the steps of: estimating the current flowing through a component; estimating the temperature of the component; comparing the estimated temperature with a desired maximum temperature for the component; and adjusting the current flowing through the component based on the result of the comparing step.
Abstract:
A sealing element (1) comprising, in cross-section, a body (7a) and a first sealing part (8a).The first sealing part (8a) providing a sealing face (12a), the first sealing part being connected to and angularly and resiliently displaceable relative to a first surface of the body (7a).
Abstract:
The present disclosure relates to a plate for use with a heatsink. The plate is adapted to engage with the heatsink and a fan subassembly, and comprises a first substantially planar section which is adapted to engage with the heatsink and a second substantially planar section which is adapted to engage with the fan subassembly.