Abstract:
The invention provides motor driving apparatus (10) for a cleaning appliance (100) comprising a battery source (12) and a power controller (16). The battery source (12) is adapted and arranged to supply the power controller (16) with an output (S1) having a first voltage (V1) which decreases as the battery source (12) is discharged. The power controller (16) is adapted and arranged to modulate the output (S1) to produce a drive signal (S2) for driving a motor (14). The drive signal (S2) has a second voltage (V2) and a variable duty cycle. The power controller (16) is adapted and arranged to increase the duty cycle of the drive signal (S2) as the first voltage (V1) decreases in order to maintain the second voltage (V2) at a substantially constant average value per unit time. By providing the above arrangement, the motor (14) can be supplied with a constant voltage throughout the available run time of the battery (12). When forming part of a cleaning appliance (100) having a motor (14), the above arrangement allows the motor (14) to operate at a substantially constant speed throughout the run time of the battery (12), resulting in more consistent cleaning performance.
Abstract:
The present patent application refers to an actuator for automotive climatization units, of the type designed to be driven by an electric control unit with direct current and low voltage, characterised in that it is provided with an electric motor able to operate at a lower voltage than the voltage delivered by the control unit and characterised in that it is provided with an electronic device able to modify the ascending ramp angle of the voltage of the successive pulses from the said control unit, in such a way that each pulse has an ascending ramp with sloped profile, so that the maximum voltage value of each pulse depends on the pulse duration.
Abstract:
Die Erfindung betrifft eine Vorrichtung zur Bereitstellung von pulsweitenmodulierten Leistungspulsen für den Motor eines Lüfters. Sie weist eine Recheneinheit und mindestens eine Leistungsendstufe auf . Die Recheneinheit und die Leistungs- endstuf e sind in einem stabförmigen Gehäuse angeordnet. Wei terhin betrifft die Erfindung einen Lüfter, welcher eine ineinem stabförmigen Gehäuse angeordnete Vorrichtung zur Bereitstellung von pulsweitenmodulierten Leistungspulsen aufweist .
Abstract:
A DC/DC bridge for controlling a direct-current load (M1), said bridge being provided with controllable semiconductor switch units (S21-S26) and having two bridge sections (B11, B12), one (B12) of which bridge sections conducts direct current while the other one (B11) is controlled via pulse-width modulation (PWM) to regulate the current magnitude, where the DC/DC bridge (B1) consists of three bridge arms, two (B111, B112) of which arms are connected in parallel, and where the semiconductor switches in the parallel-connected bridge arms are controlled via PWM to form a PWM-controlled bridge section.
Abstract:
A system and method for measuring fluid or gas flow rate, for the system where fluid or gas is pumped, such as gas monitoring instrument, via a conduit to a sensor. The flow of gas through a pump (14) is determined by measuring motor back emf which is proportional to motor (12) speed. The motor (12) speed is controlled by pulse width modulation "PWM" control (40) of the motor drive (38) voltage. The back emf is sampled (44) during intervals between the drive pulses applied to the motor (12). The sampling is done at selected, spaced-apart or infrequent intervals such as ones for every ten or once for every hundred motor drive pulses. In an instrument that uses a microprocessor (56) and analog-to-digital converter (50) to measure gas concentration, the same microprocessor (56) and converter (50) can provide the PWM control of the pump (14) in response to back emf generated by the pump motor between the drive pulses. The output of the analog-to-digital converter (50) that corresponding to the back emf, which in turn corresponds to the pump motor speed is compared via microprocessor (56) to set-point value of the desired pumpmotor speed. The processor then adjusts the PWM to remain the desired motor (12) speed.
Abstract:
A block diagram of circuitry, including control circuits contained within package (33). Thus, MOSFETS (31) and (33) are provided with respective shoot-thru protection circuits (61) AND (62) respectively and with over current shut down circuits (63) and (64) respectively.
Abstract:
A control system for driving a power tool is provided comprising a power source, a motor adapted to drive a shaft, a power switching unit interconnecting the power source and the motor, and a controller. The power switching unit applying a pulse width modulated (PWM) drive signal from the power source to the motor. The controller monitoring at least one electrical characteristic of at least one of the power source, motor and power switching unit and adjusting the operating duty cycle of the PWM drive signal based on the electrical characteristics.
Abstract:
A speed controller operates a DC-powered fastener drive assembly to efficiently drive fasteners from a DC power supply (22), thereby achieving a fully portable hand tool. In particular, the speed controller accelerates a flywheel (28) with a DC motor to a target speed appropriate for the type of fastener and user selection. Thereafter, the speed controller causes the kinetic energy from the flywheel (28) to be imparted to a linearly moving fastener driver. The speed controller is responsive to the rotational speed of the flywheel (28) to ensure a consistent depth of drive and to actuate a clutch for an appropriate amount of time to couple the flywheel (28) to the fastener driver. Thereby, consistent drives are achievement across a range of operating conditions (e.g., battery state of charge, type of fastener, mechanical tolerances and wear, motor performance, etc.).