Joulwatt Technology (hangzhou) Co., Ltd.

Other

Yue Ji

Xunwei Zhou

Yuancheng Ren

Pitleong Wong

Yang Lu

A circuit and a method for detecting a current zero-crossing point, and a circuit and method for detecting a load voltage are disclosed. The circuit for detecting current zero-crossing point includes: a load power supply circuit, a voltage-dividing resistor, a transistor switch, a zero-crossing detection circuit; the load power supply circuit includes: a load, a diode, and a transformer; one end of a primary winding of the transformer is connected with the operating voltage input terminal, the other end of the primary winding of the transformer is connected with a first end of the transistor switch and a first end of the voltage-dividing resistor, a second end of the voltage-dividing resistor and a second end of the transistor switch are connected with the ground, the load voltage is controlled by the transistor switch.

Circuit and method for detecting current zero-crossing point and circuit and method for detecting load voltage

A circuit and a method for detecting a current zero-crossing point, and a circuit and method for detecting a load voltage are disclosed. The circuit for detecting current zero-crossing point includes: a load power supply circuit (), a voltage-dividing resistor (), a transistor switch (), a zero-crossing detection circuit (); the load power supply circuit () includes: a load (), a diode (), and an inductor (); one end of the load power supply circuit () is connected with the operating voltage input terminal, the other end of the load power supply circuit () is connected with a first end of the transistor switch () and a first end of the voltage-dividing resistor (), a second end of the voltage-dividing resistor () and a second end of the transistor switch () are connected with the ground, the load voltage is controlled by the transistor switch (), the voltage-dividing terminal of the voltage-dividing resistor () is connected to a signal input terminal of the zero-crossing detection circuit (), the zero-crossing detection circuit () is used to determine whether the current of the diode () crosses zero to obtain the on time of the diode (), and the circuit for detecting load voltage uses the on time of the diode () and the on time of the transistor switch () to obtain the load voltage. The circuits are simple, but with high detection efficiency and low cost.

Circuit and method for detecting current zero-crossing point, and circuit and method for detecting load voltage

A system and method for dimming an LED lighting installation using an AC power source are disclosed. The disclosed LED lighting system includes an LED light having one or more LEDs, a dimming control module for controlling and adjusting brightness level of the LED light toward a desired target brightness, and a user-operated lighting control device including a power on/off switch and a dimmer. The power on/off switch passes or interrupts the AC power fed into the dimming control module. A series of turned-off operations of the power on/off switch of transitory duration causes LED light target brightness levels to be progressively increasing or decreasing leading to a desired target brightness. Operations of the dimmer result in a target brightness setting signal being generated for the dimming control module, representative of a desired target brightness as well.

Growing community of inventors

Hangzhou, China

Yue Ji