【 Weak current College 】 affect prepaid water meters of the main design factors

Prepaid water meters is the rise in recent years China's new residential water metering and settlement of instrument, it directly to people, accuracy and reliability are particularly important. Pre-paid water meters in the design-time should be considered in conjunction with its working principle and structure characteristics, with particular attention to the following main factors.
Electro-mechanical switching device is prepaid water meters measure the performance of one of the main factors, it must meet the controller's low-power design requirements. The industry's most magnetic-Double Reed pipe, its electrical output signal switching device is switched on the substance of the signal, low-power, but there is poor resistance to jitter and steering characteristics of the poor. Rather magneto-double ten spring tube in terms of resistance to jitter with strong advantages, is now widely adopted. In many of the instruments adopt magnetic-double ten spring tube sampling mode and attach a steering Reed pipe (reach steering attack function). However, this design if there is no valid controller signal recognition method support, in theory cannot be completely overcome jitter interference. Found by analysis, hardware on magnetic-double ten spring tube using sampling mode, the controller's software uses the combination of identification and identification techniques for sampling delay signal recognition, in theory, can be completely overcome jitter interference and magnetic interference, can greatly improve the reliability of prepaid water meters measure (for details, refer to the Chinese metrology magazine issue 2 2004 the prepayment meter traffic signals and mechanical conversion optimization ").
Electric control valve is prepaid water meters measure the performance and reliability of another major factor. Electric control valve on the water meter measurement performance impact depends on the valve structure, in particular the choke part structure. Valve's flow part can usually drag depending on whether or not to change the flow direction is divided into two kinds. Change the direction of flow, valve structure may be on the water meter measurement performance have a greater impact. Research has shown that flows through the water meter measuring bodies of water, when the channel change, because of the impact on meter internal secondary flow, its direction and strength and resistance of the structure of flow parts. When the second stream of sufficient strength and water meter flow measuring element of direction of rotation, the secondary flow accelerates flow measuring element of speed, meter high area curve measurement error gets upwards morphology; on the contrary, the measurement error of the meter high area curve illuminates to droop.
When the water mass occurrence of such a character error curve has been unable to adopt water meter internal regulation device implementation error curve of the migration, you should review the implementation of error curve of the migration, you should re-examine the valve spoiler parts of structure design. Usually by adjusting the structure of the runner, transition parts as possible, avoid sharp angles, arc in the process improve the smoothness of the wall, thus, to a certain extent, can improve the error curve characteristics. Without changing the flow direction of the valve structure, to the meters measure the error curve has little to no impact. In addition, the circulation capacity to change the direction of the valve flow structure as a direct result of flow through a collision energy loss, to the meters of pressure loss specifications have a greater negative impact.
Electric control valve as executing agency, is the most power meter single work, therefore at design time in order to achieve the purpose, requires power electric control valve in contradiction of load capacity, are usually too small load capacity affect the reliability of the valve movement. Electric control valve'sactuator with electromagnetic and electric motor. Electromagnetic actuator was generally not a reduction gear box, do one of the high efficiency, driving current is also relatively small. But because of the closing valve speed too high, the pipeline will have the effect of water hammer, vacuum, instantly would have an impact on the instrument and pipeline damage. In addition, the valve seals are fast, easily damaged and affect the service life. Motor-driven institutions usually in motor and valve action parts room equipped with gear transmission, the driving current General is large, but due to the extended on-off valve, an effective solution to the shortcomings of the electromagnetic drive.
Affect the performance of pre-paid water meters and another factor is the power supply battery performance. The battery itself of technical performance, though important, but more important is to have the battery performance and the overall performance of the meter to match the design concept. In pre-paid water meters in the design process, the main consideration should be given a battery of load and discharge characteristics.
Battery load resistance including high voltage load and low voltage at the load characteristics, this was largely considered the electric control valve movement, when the electronic control valve switching valve, due to produce high-current, battery voltage drop U, high ¡÷ voltage, reduced voltage after still controller micropower single-chip allows the voltage range. But when the battery is spent several years later, the voltage is reduced to near-chip allows lower operating voltage, battery low voltage at the load characteristic may affect the reliability of the controller. When a voltage drop U, actual △ supply voltage is lower than the minimum operating voltage controller, single chip die chance to crash, leading to electronic control valve action does not execute or perform half, memory disorders, and other data.
Battery's discharge characteristics means the battery time and output voltage. In the design life of the battery voltage falls from high voltage to low voltage U1 U2, U2 is a meter controller allows minimum operating voltage. The voltage values are usually available as power under voltage protection design values of the reference value, but U2-△ U should meet the minimum micro-power single-chip voltage.
Through the analysis can be found, the above three factors on the impact of pre-payment meter is not entirely independent, in particular in terms of reliability and controller design. Thus you can analyze the section with the controller interface and parameter control requirements to guide the design of the technical parameters of the controller.