Low voltage detection easily copes with the power supply troubles of ultrasonic meter applications
Ultrasonic flow meters, including ultrasonic water meters, ultrasonic heat meters, and ultrasonic gas meters, are fully electronic flow meters made of industrial-grade electronic components using the principle of ultrasonic time difference. Using a pair of ultrasonic transducers to send and receive ultrasonic waves alternately (or simultaneously), the flow velocity of the fluid is indirectly measured by detecting the propagation time difference between the forward and reverse flow of the ultrasonic waves in the medium, and then the flow rate of the fluid is calculated by the flow velocity.
Compared with traditional mechanical flow meters, ultrasonic flow meters have very important advantages: high precision, good reliability, wide range ratio, long life, no moving parts, can be installed at any angle, very flexible replacement, etc.
However, for the application of the all-electronic smart flow meter, it is usually powered by a battery, and the battery is required to be used for at least 6 years. Therefore, this puts forward very strict requirements on the power consumption of the entire system, and has always restricted the development of ultrasonic flow meters. With the birth of ultra-low-power MCU and ultra-low-power ultrasonic dedicated measurement chip, the new ultra-low-power ultrasonic flow meter solution has successfully solved the problem of power consumption and met customer requirements. However, with the rise of the wireless centralized meter reading system, the power consumption problem is facing a severe test. The wireless module not only increases the power consumption, but also, due to the difference in the communication distance or the number of wall penetrations, the radio frequency transmission power is different, and the power consumption of each flow meter unit is also different, resulting in different battery life. The original method of uniform battery replacement is not very desirable.
We can detect the battery voltage. When the battery voltage is lower than a certain voltage value, an alarm will be sent to notify the system that the battery voltage is low and it is time to replace the battery. In this way, the battery can be replaced according to the actual service life of the battery, which can save costs on the one hand, and can prevent the battery voltage from being too low, which will lead to the failure of the flow meter and false reports and missed reports.
Voltage detection, there are many ways to achieve. One method is to use the AD conversion of the CPU itself to do voltage detection, but its power consumption is too large, and it cannot be detected from time to time, and the detection period needs to be set. If the detection period is set longer, the power consumption is small, but it is easy to miss detection. If the detection period is set short, the power consumption is too large, so it is not ideal. Another method is to use a special voltage detection chip for voltage detection. Once the voltage is lower than a certain voltage threshold, an alarm will be prompted.
Sh-meters produces various types of ultrasonic water meters, welcome to provide you with more suitable water meter solutions, and look forward to your consultation.