Programmable power circuit of meter bus slave

The invention relates to a power circuit of a meter bus slave, belonging to the technical field of apparatus meters. The programmable power circuit of the meter bus slave consists of a program-controlled reference voltage generating circuit and an emitter follower, wherein the program-controlled reference voltage generating circuit consists of resistors, two voltage-stabilizing diodes, a reinforced NMOS (n-channel metal oxide semiconductor) tube and a singlechip MCU (micro control unit); a resistor R1 is serially connected with the two voltage-stabilizing diodes; the reinforced NMOS tube which is connected with one voltage-stabilizing diode in parallel is connected with a grid electrode of an NMOS tube VM through an I/O (input/output) port of the singlechip MCU; a resistor R2 is connected between the I/O port of the singlechip MCU and the grid electrode of the NMOS tube VM; a resistor R3 is connected between the I/O port of the singlechip MCU and a positive power supply; the emitter follower comprises two dynatrons V1 and V2 which are connected in a Darlington way; collector electrodes of the two dynatrons V1 and V2 are connected with a high voltage end of the meter bus; emitter electrodes of the dynatrons are connected on a slave load RL; and a substrate of the emitter follower formed by the two dynatrons is connected with the output of the program-controlled reference voltage generating circuit.