Low power consumption power supply circuit of meter bus slave computer

Abstract

The invention relates to a low power consumption power supply circuit of a meter bus slave computer, which belongs to the technical field of instruments and meters and comprises a constant voltage source circuit with high pressure resistance and low quiescent current and a low-pass filter circuit, wherein two triodes which are connected into a Darlington form are used as an emitter follower of the constant voltage source circuit, the base electrode of the emitter follower is connected with a standard voltage generated by a voltage reference, and a voltage with low output resistance is output from an emitter to form a constant voltage source; the low-pass filter circuit is formed by connecting a resistor with a low resistance value and a capacitor in series; and the emitter of the emitter follower is connected with the resistor of the low-pass filter circuit. Compared with the solution of the prior art, the current consumption of the slave computer in a dormant state is greatly reduced on the basis of not increasing the cost of the single slave computer, thus the overall energy consumption is reduced, and meanwhile, the number of the slave computers of a traditional meter bus network can be greatly increased, and the nodes of the meter bus network can be increased. The low power consumption power supply circuit of the meter bus slave computer is particularly suitable for low power consumption meter bus systems, such as water meters, gas meters and the like.

Description

technical field [0001] The invention relates to a power supply circuit of an instrument bus slave, belonging to the technical field of instruments and meters. technical background [0002] Meter-Bus (M-Bus for short) is a new type of serial bus standard, which is mainly used in the networking of consumption measuring instruments such as water meters, gas meters and thermal instruments. Because the instrument bus has the advantages of convenient networking, low cost and strong anti-interference ability, it has become the European standard for 2-wire bus. widely used. The main feature of the instrument bus is that only two non-polar wires are used as the power supply line and the data line for transmitting serial data at the same time. All terminal devices are connected in parallel on these two lines. Different nodes on the bus are distinguished by different address codes. . [0003] According to the different roles played in the instrument bus communication, the nodes of t...

AI Technical Summary

Problems solved by technology

But the current of the constant current source of the slave power supply circuit can only be in accordance with I active +I s The reason is: if the constant current source current is less than this value, the current provided by the power supply circuit will not be able to meet the needs of the active slave system, which will cause the active slave to be unable to obtain a stable power supply voltage

But most of the slaves in sleep state only need I sleep +I s current, in this case the excess current (size: I active -I sleep ) will be wasted in DW 1 superior

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