Use temperature monitoring intelligent LED light safety improvement

For a conventional filament type bulb, the thermal temperature generated by the filament is properly isolated and does not conduct due to direct contact. In the case of LED lighting fixtures, the LED is the light source, and the heat generated by the LED directly contacts the LED bulb to generate heat conduction. Direct contact is due to the fact that the LED must be mounted to the driver circuit. To remove heat, the thermal temperature must be dissipated from the LED and the driver circuit through heat dissipation or thermal management. Thermal management or heat dissipation is a necessary task to keep LED lighting fixtures running for hours.

For example, replacing a luminaire on a general lamp holder with an LED lamp, such as a wall lamp or a recessed ceiling lamp, is controlled by a switch on the wall. The heat dissipation efficiency of this kind of application is not ideal, because the heat generated by most standard lamps is to dissipate the heat temperature emitted by the lamps through heat convection or airflow, and the original heat dissipation mechanism of the wall lamp or the embedded ceiling lamp is for the general bulb. Designed.

Failure to do enough thermal management may result in the need to replace faulty LED lights, or even a serious disaster in the entire building. The use of intelligent LED lighting control technology to monitor the temperature of LED lamps can greatly simplify the work of thermal management, and the lamps will reduce their power due to temperature rise, and LED lamps will be safer.

NTC monitors temperature to maintain LED light safety

The purpose of the NTC circuit is to improve the safety of the LED luminaire by monitoring the temperature of the LED luminaire and to reduce the complexity of the design. When the temperature rises, the controller will reduce the brightness and keep the LED light in a safe range. That is to say, when the temperature rises, the brightness is lowered, and when the temperature is lowered, the brightness is increased.

In order to measure the temperature change of the LED lamp, the voltage measured by the NTC can be measured, and the measured voltage has a direct relationship with the temperature of the NTC. When the temperature of the NTC and the surrounding circuit rises, the resistance of the NTC decreases. The basic method can measure the temperature through NTC. The first method is to treat the NTC as a voltage divider circuit, connect the system to a known voltage, and measure the voltage at the NTC node. When the NTC temperature increases, the resistance will drop. A drop in resistance causes a change in the voltage-to-voltage ratio, and the voltage at the NTC node also drops as the temperature rises.