What is temperature humidity sensor?
Temperature and humidity sensor (or rh temp sensor) is devices that can convert temperature and humidity into electrical signals that can easily measure temperature and humidity. Temperature humidity transmitters on the market generally measure the amount of temperature and relative humidity in the air, and convert it into electrical signals or other signal forms according to certain rules and output the device to the instrument or software to meet the environmental monitoring needs of users.
What is the principle of humidity transducer explain?
The components of the temperature and humidity sensor module mainly include a humidity sensitive capacitor and a conversion circuit. The humidity sensitive capacitor is composed of a glass substrate, a lower electrode, a humidity sensitive material, and an upper electrode.
Humidity sensitive material is a kind of high molecular polymer, its dielectric constant changes with the relative humidity of the environment. When the environmental humidity changes, the capacitance of the humidity sensitive element changes accordingly. That is, when the relative humidity increases, the humidity sensitive capacitance also increases, and vice versa. The conversion circuit of the sensor converts the change in humidity-sensitive capacitance into a change in voltage, which corresponds to a change in relative humidity of 0 to 100% RH. The output of the sensor shows a linear change of 0 to 1v.
How to monitor various climate factors and wirelessly communicate with heating, ventilation and air conditioning (HVAC) systems and other intelligent building management systems, while significantly decreasing maintenance costs.
As shown in the figure, the Air quality sensor consists of several parts, namely Non-isolated DC/DC power supply、Motion detection、Temperature sensor、Ambient light sensor、Signal input/output protection、Digital processing、Self-diagnostics/monitoring、Energy storage、Wireless interface.
Non-isolated DC/DC power supply
Long battery life is a key design consideration. Buck converters with high light-load efficiency may be considered for designs prioritizing maximum battery life. For designs operating from a low voltage battery, boost converters may be used instead. Non-isolated DC/DC power supply includes Boost converters (integrated switch)、Linear & low-dropout (LDO) regulators、Buck-boost, inverting & split-rail converters (integrated switch)、Series voltage references、Supervisor & reset ICs、Load switches、Shunt voltage references、Buck converters (integrated switch)、P-channel MOSFETs、Real-time clocks (RTCs) & timers、Analog switches & muxes, the Corresponding product models are TPS61299、TPS7A24、TPS63900、REF35、TPS3840、TPS22916、LM4040-N、LMR54406、CSD75207W15、TPL5010、TS5A3159A
Motion detection
A passive infrared (PIR) sensor can be used for room occupancy or motion detection. Motion detection includes General-purpose op amps、Precision op amps (Vos<1mV)、Comparators、Series voltage references、Shunt voltage references、Precision ADCs, the Corresponding product models are TLV9302、OP07C、TLV3691、REF35、LM4040-N、ADS1015
Temperature sensor
Temperature and humidity are closely monitored by wireless environmental sensors. A humidity sensor with integrated temperature sensor can be an option for designs requiring both sets of data. A standalone temperature sensor or a thermistor with a corresponding operational amplifier may be used in designs that only require temperature data. Temperature sensor includes Humidity sensors、General-purpose op amps、Precision op amps (Vos<1mV)、Comparators、Series voltage references、Shunt voltage references、Precision ADCs, the Corresponding product models are HDC3022、TLV9062、OP07C、TLV3691、REF35、ADS1015
Ambient light sensor
A light-to-digital sensor with integrated amplifier, analog-to-digital converter, and digital interface can be used for faster time-to-market and ease-of-use. A light dependent resistor may also be used. Ambient light sensor includes Light sensors、General-purpose op amps、Precision op amps (Vos<1mV)、Comparators、Series voltage references、Shunt voltage references、Precision ADCs, the Corresponding product models are OPT3002、TLV9302、OP07C、TLV3691、REF35、ADS1015
Signal input/output protection
An ESD protection device may be required for protection on user buttons. Signal input/output protection includes ESD protection diodes, the Corresponding product models are TPD4S012、TPD1E10B06
Digital processing
The design can use a dedicated microcontroller or a single system-on-chip solution which combines the microcontroller and radio on a single device. Digital processing includes Arm Cortex-M0+ MCUs、MSP430 microcontrollers、Low-power 2.4-GHz products、Sub-1 GHz wireless MCUs、Sub-1 GHz transceivers、Wi-Fi products、Series voltage references、Supervisor & reset ICs、Shunt voltage references、Noninverting buffers & drivers, the Corresponding product models are MSPM0L1306、MSP430G2553、CC2674R10、CC1352R、CC110L、CC3220SF、REF35、TPS3839、LM4040-N、SN74LVC2G17
Self-diagnostics/monitoring
A voltage supervisor can be used to keep the microcontroller in reset until valid voltage levels are reached. Self-diagnostics/monitoring
includes Supervisor & reset ICs, the Corresponding product models are TPS3839、TPS3840
Energy storage
Wireless environmental sensors may harvest energy from a window or light source. An ultra low power harvester power management IC can be used to charge a super capacitor or rechargeable battery using a solar cell. Energy storage includes Load switches、Battery charger ICs、Analog switches & muxes、Real-time clocks (RTCs) & timers, the Corresponding product models are TPS22916、BQ25570、TS5A3160、TPL5100
Wireless interface
A system-on-chip solution which integrates a microcontroller and radio allows designs to run the application layer and wireless protocol stack on one chip. A microcontroller with dedicated RF radio topology allows designs to separate the wireless protocol stack from the application layer. Wireless interface includes Low-power 2.4-GHz products、Sub-1 GHz wireless MCUs、Other wireless products、Sub-1 GHz transceivers、Wi-Fi products, the Corresponding product models are CC2674R10、CC1352R、TRF7970A、CC1120、CC3220SF
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