Abstract: The present invention provides waterborne curable film-forming compositions comprising: a) an aqueous dispersion of polymeric acrylic particles, wherein the particles have a Z average particle size less than 80 nm and have reactive functional groups; wherein the particles are prepared from a monomer mixture comprising ethylenically unsaturated monomers that are polymerized in the presence of a branched polymer having an acid value of 40-200, wherein the branched polymer is prepared from ethylenically unsaturated monomers; b) a crosslinking agent having functional groups reactive with functional groups on the polymeric acrylic particles; and c) an aqueous dispersion of at least one additional polymer having hydroxyl and/or acid functional groups and having a Z average particle size greater than 100 nm. Further provided are multilayer coated substrates comprising the curable film-forming compositions and methods for forming a composite coating on a substrate using the curable film-forming compositions.

Abstract: The present invention provides waterborne curable film-forming compositions comprising: a) an aqueous dispersion of polymeric acrylic particles, wherein the particles have a Z average particle size less than 80 nm and have reactive functional groups; wherein the particles are prepared from a monomer mixture comprising ethylenically unsaturated monomers that are polymerized in the presence of a branched polymer having an acid value of 40-200, wherein the branched polymer is prepared from ethylenically unsaturated monomers; b) a crosslinking agent having functional groups reactive with functional groups on the polymeric acrylic particles; and c) an aqueous dispersion of at least one additional polymer having hydroxyl and/or acid functional groups and having a Z average particle size greater than 100 nm. Further provided are multilayer coated substrates comprising the curable film-forming compositions and methods for forming a composite coating on a substrate using the curable film-forming compositions.

Abstract: A fan speed control circuit is used for controlling rotation speed of a fan. The fan speed control circuit receives a pulse width modulation (PWM) signal from a system and comprises a programmable control unit and a current control unit. The programmable control unit receives the PWM signal, is connected to a Hall element for receiving a voltage signal therefrom, and provides a control signal. The current control unit takes the control signal to control current flowing through a stator coil unit of the fan so as to control the speed of the fan. The programmable control unit has a program written for the PWM signal, and when the fan speed control circuit is used in another system with a different PWM signal, the programmable control unit can be given a new program for the different PWM signal for controlling the speed of the fan.

Abstract: An apparatus is used for controlling a rotating direction of a fan. The apparatus comprises a power source, a signaling unit, a switching unit, and an activating module. The power source is used for supplying power for the apparatus. The signaling unit is used for generating direction-control signals. The switching unit is connected to the power source and the signaling unit, and used for controlling the switching unit to work. The activating module is connected to the switching unit and the fan, and used for driving the fan to selectively rotate in one of two opposite directions based on the direction-control signals. A method for driving the fan in the two directions is also disclosed.

Abstract: A fan speed control circuit is used for controlling rotation speed of a fan. The fan speed control circuit receives a pulse width modulation (PWM) signal from a system and comprises a programmable control unit and a current control unit. The programmable control unit receives the PWM signal, is connected to a Hall element for receiving a voltage signal therefrom, and provides a control signal. The current control unit takes the control signal to control current flowing through a stator coil unit of the fan so as to control the speed of the fan. The programmable control unit has a program written for the PWM signal, and when the fan speed control circuit is used in another system with a different PWM signal, the programmable control unit can be given a new program for the different PWM signal for controlling the speed of the fan.

Abstract: An apparatus is used for controlling a rotating direction of a fan. The apparatus comprises a power source, a signaling unit, a switching unit, and an activating module. The power source is used for supplying power for the apparatus. The signaling unit is used for generating direction-control signals. The switching unit is connected to the power source and the signaling unit, and used for controlling the switching unit to work. The activating module is connected to the switching unit and the fan, and used for driving the fan to selectively rotate in one of two opposite directions based on the direction-control signals. A method for driving the fan in the two directions is also disclosed.