Abstract: The power supply (20) for LEDs provides power to a LED light source (10) having a variable number of LEDs wired in series and/or in parallel. The power supply (20) uses current and voltage feedback to adjust power to the LEDs and provides protection to the LED light source (10). A feedback controller (27) compares sensed current and sensed voltage to a reference signal and generates a feedback signal, which is processed by a power factor corrector (124) to adjust the current flow through the transformer supplying current to the LEDs. A LED control switch (24) clamps a peak of the current to the LEDs to provide further protection to the LED light source (10). A short/open detection circuit (30) indicates any detection of a “LED outage” of the LED light source (10).

Abstract: A circuit and method measures main motor winding voltage and detects points in the electromagnetic wave cycle where this voltage “crosses” zero. It also measures auxiliary motor winding voltage. Phase shifts measured in the auxiliary winding are compared as a means for starting and restarting the auxiliary winding. The points in the electromagnetic wave cycle where the current in the auxiliary winding “crosses” zero are detected and compared with a first window pulse that is generated when the main voltage crosses zero. When the zero current crossing points fall outside the first window pulse, the auxiliary winding is disconnected. The points where the voltage in the auxiliary winding “crosses” zero are also detected and compared with a second window pulse that is generated when the main voltage crosses zero. When the zero voltage crossing points fall within the second window pulse, the auxiliary winding is switched back into the circuit.

Abstract: A circuit and method measures the voltage at the main motor winding (1) and detects the points in the electromagnetic wave cycle at which this voltage “crosses” zero. The method and circuit also measures the voltage at the auxiliary motor winding (2). The voltages measured in the main winding (1) and in the auxiliary winding (2) are compared by the circuit (13) as a means for starting and restarting the auxiliary winding (2). The circuit and method also detects the points in the electromagnetic wave cycle where the current in the auxiliary winding “crosses” zero and compares the phase of these current zero crossing points with a window pulse (11) that is generated when the main voltage crosses zero. When the zero current crossing points fall within the window pulse, the auxiliary winding (2) is up to proper operating speed and the auxiliary winding (2) is disconnected by the starting circuit.

Abstract: A circuit and method measures the voltage at the main motor winding (1) and detects the points in the electromagnetic wave cycle at which this voltage “crosses” zero. The method and circuit also measures the voltage at the auxiliary motor winding (2). The voltages measured in the main winding (1) and in the auxiliary winding (2) are compared by the circuit (13) as a means for starting and restarting the auxiliary winding (2). The circuit and method also detects the points in the electromagnetic wave cycle where the current in the auxiliary winding “crosses” zero and compares the phase of these current zero crossing points with a window pulse (11) that is generated when the main voltage crosses zero. When the zero current crossing points fall within the window pulse, the auxiliary winding (2) is up to proper operating speed and the auxiliary winding (2) is disconnected by the starting circuit.

Abstract: The power supply (20) for LEDs provides power to a LED light source (10) having a variable number of LEDs wired in series and/or in parallel. The power supply (20) uses current and voltage feedback to adjust power to the LEDs and provides protection to the LED light source (10). A feedback controller (27) compares sensed current and sensed voltage to a reference signal and generates a feedback signal, which is processed by a power factor corrector (124) to adjust the current flow through the transformer supplying current to the LEDs. A LED control switch (24) clamps a peak of the current to the LEDs to provide further protection to the LED light source (10). A short/open detection circuit (30) indicates any detection of a “LED outage” of the LED light source (10).

Abstract: The driver circuit for light emitting diodes (LEDs) of the present invention provides power to LEDs using pulse width modulation (PWM). The driver circuit 100 uses current feedback to adjust power to LED arrays 54 and provides a full light and a dim mode.

Abstract: The driver circuit for light emitting diodes (LEDs) of the present invention provides power to LEDs using pulse width modulation (PWM). The driver circuit 100 uses current feedback to adjust power to LED arrays 54 and provides a full light and a dim mode.

Abstract: A control circuit (10) is provided for automatically re-applying starting torque to a single phase AC induction motor by reconnecting the auxiliary or starting winding (2) to the AC power source (3) if the motor has not accelerated to a given cut-out speed, or otherwise begins to stall. Multiple reconnections of the auxiliary winding (2) are automatically provided as needed, without external intervention, to provide multiple bumping action. The auxiliary winding (2) is connected to the AC source (3) during initial energization of the motor, and is disconnected after a given starting interval. Induced voltage in the auxiliary winding (2) is sensed and compared against a reference voltage (17) for reconnecting the auxiliary winding (2) when the sensed auxiliary winding voltage drops below a given value relative to the reference voltage. The disconnecting, sensing and reconnecting functions are accomplished with a minimum number of components.

Abstract: A speed sensitive, load sensitive and AC line voltage fluctuation insensitive, motor starting system is provided for an AC motor having a main winding (1) and an auxiliary winding (2) both connectable across an AC power source (3). Relative magnitudes of main and auxiliary winding voltages are sensed and compared. The auxiliary winding is disconnected (5) from the AC source when the auxiliary winding voltage, including the components from the AC source and from rotationally induced voltage, rises above a predetermined value relative to the main winding voltage as a function of motor speed. After starting, when the motor is in a run mode and the auxiliary winding is disconnected from the AC source, only the rotationally induced auxiliary winding voltage is sensed.

Abstract: In an AC motor having a main winding (1) and a start winding (2) both connectable to an AC power source (3), and having a switch (22) for disconnecting the start winding from the AC source, an improved control circuit for the switch is provided. A pulse generator (15) responds to main and start winding or capacitor voltage sensors (11 and 12) for generating a first set of variable width output pulses (16) having a width determined by the phase differential between the voltages. A comparator timer (17) responds to the pulse generator for outputting a second set of variable width pulses (18) having a width determined by the amount of which the pulse width of the pulses of first set (16) exceed a selected duration (42). An output pulse detector (20) responds to the comparator timer for detecting the second set of variable width pulses and outputs a delayed turn-off signal (21) to the switch (22).