How to protect outdoor cameras from extreme weather with temperature switches?
Outdoor cameras play an important role in security applications, so whether they are in tropical, cold, or climates with extreme differences in daily temperature, you need to ensure that they do not malfunction or malfunction.
Older outdoor cameras can only operate reliably over a specific temperature range. When the temperature is low, the internal resistance of the lithium battery is large, which causes the battery capacity to rapidly degrade and even fail. At high temperatures, the camera's image sensor may produce "hot pixels," bright single pixels that can adversely affect overall image quality.
Designing an outdoor camera that can withstand a wide range of ambient temperatures from -30 ° C to + 55 ° C faces two main design challenges. The first challenge is the ability to start at very high / low temperatures. The second challenge is to accurately measure the temperature over a wide temperature range, because the operation of the fan or heater installed inside the camera is based on the temperature measurement. Accurate temperature results maximize the camera's operating temperature range and prevent equipment failure.
A design with a temperature switch can help address these two challenges.
How fans and heaters operate efficiently
Outdoor cameras, especially high-definition cameras, generate higher energy. When the ambient temperature is high, the fan can reduce the internal temperature to keep the camera running normally. In extreme cold conditions, although the camera generates a lot of heat, this heat is not enough to allow it to operate above the minimum operating temperature. Therefore, when the ambient temperature is low, a heater can be used to raise the internal temperature.
The microcontroller (MCU) or processor starts first and detects the temperature with the help of a sensor. However, if the temperature is too low or too high, the MCU or image sensor may be damaged when trying to start. To avoid this, outdoor camera designs should restore the camera to its minimum operating temperature before attempting to start the camera.
The TMP390 dual channel temperature switch provides independent over- and under-temperature detection without using an MCU. Since the temperature switch directly controls the fans and heaters, it can provide the entire system with the proper temperature before the MCU starts, preventing the MCU from operating at extremely high or low temperatures. Resistor-programmable temperature trip points provide flexibility for a variety of applications, while resistor-programmed 5 ° C or 10 ° C thermal hysteresis options prevent unnecessary digital output switching.
During startup at extremely low temperatures, the temperature switch will start first after the power is turned on; the MCU or other components remain off. When the temperature exceeds the safe range, it is in an active low level, and at the same time, the heater and fan begin to increase the internal temperature. When the temperature reaches the preset value, the entire system starts. The TMP390 temperature switch adjusts the temperature before the system starts, thereby solving the challenge of starting at very low or very high temperatures.
The TMP390 temperature switch has 3C accuracy from -55 ° C to + 130 ° C (± 1.5 ° C from 0 ° C to + 70 ° C), which provides sufficient accuracy over a wide temperature range. With accurate temperature measurement, the outdoor camera no longer needs to make room for temperature protection, which can maximize the operating temperature range and effectively protect the equipment in the system. Because the TMP390 temperature switch can precisely control the fan or heater, unnecessary energy consumption in outdoor cameras can be saved.
If you want to know more, our website has product specifications for the switches， you can go to ALLICDATA ELECTRONICS LIMITED to get more information