CN2283862Y - Multifee rate card type kilowatt-hour meter - Google Patents

Abstract

The utility model relates to a kilowatt-hour meter which comprises an induction type kilowatt-hour meter and a control circuit composed of a backup battery, a function key, a buzzer, a photoelectric sensor, a single-chip microcomputer, an electric card, an electric card read-write device, a clock and a data storing chip, a serial-to-parallel conversion chip, a display, a cut-off relay. The photoelectric sensor is arranged at the scale of the induction type kilowatt-hour meter, and the output of the photoelectric sensor is connected with the interruption foot of the single-chip microcomputer. The function key is connected with the other interruption foot of the single-chip microcomputer, and the data end and the clock end of the electric card read-write device, the clock and the data storing chip are respectively connected with the two input-output feet of the single-chip microcomputer. The power supply ends of the clock and the data storing chip are connected with the backup battery, and the input-output feet of the single-chip microcomputer is connected with the buzzer and the relay. A serial port is connected with the display via the serial-to-parallel conversion chip. The utility model has the advantages of low cost and high reliability, and has the functions of planning power consumption and prepaying the electric charge.

Description

Multiple charge rate electric card type watt-hour meter

The utility model relates to a kind of electric card type watt-hour meter, belongs to electrician's metering outfit field.

Watt-hour meter is to be used for recording user institute power consumption, the foundation that collects charges for electricity as power supply management department nuclear.Traditional induction meter mainly is made of solenoid and mechanical counter, and it can only write down power consumption, can not control user's power mode, thereby be unfavorable for taking over of the planned supply and use of electric power and the electricity charge.At this kind situation, existing micro-processor controlled at present multiple charge rate digital kilowatt-hour meter occurs, it adopts electricity charge card (electricity card or magnetic card) and computer metering control circuit, electricity charge card is sold according to plan by power supply department, metering circuit measures institute's power consumption, when purchasing electric weight and exhaust in the electricity charge card, control circuit cuts off power supply, thereby has reached the purpose of planned supply and use of electric power and electric fees charging.But its cost is higher than the traditional electrical kilsyth basalt, and under the low price situation, can not reach higher measuring accuracy.

In view of above-mentioned, the utility model will provide that a kind of cost is low, reliability is high and have planned supply and use of electric power and the multiple charge rate electric card type watt-hour meter of prepayment electric expense function.

For reaching above purpose, the utility model adopts following scheme:

Multiple charge rate electric card type watt-hour meter, comprise induction meter and control circuit, it is characterized in that: described control circuit is by direct supply, reserve battery, function key, hummer, photoelectric sensor, single-chip microcomputer, electricity card and electric card reader, clock and data are preserved chip, string and conversion chip, display and the cut-off relay that is serially connected in the current supply circuit are formed, wherein: photoelectric sensor is contained in the scale place of induction meter, its output connects an interruption pin of single-chip microcomputer, function key connects another interruption pin of single-chip microcomputer, the electricity card reader, clock and data preservation both data terminals of chip and clock end connect two input and output pin of single-chip microcomputer respectively, clock and data are preserved the power supply termination reserve battery of chip, an input and output pin of single-chip microcomputer connects hummer, another input and output pin of single-chip microcomputer connects the control end of cut-off relay, the serial port of single-chip microcomputer connects the segment data mouth of display through string and conversion chip, and the input/output port of single-chip microcomputer connects the bit data end of display.

After the user will insert electric card reader from the electricity card that power supply administration buys, the electric weight of putting down in writing in the card was deposited in data and is preserved in the chip.After this single-chip microcomputer carries out stored count to the power consumption of photoelectric sensor collection, and more new data is preserved the electric weight of depositing in the chip, and when depositing electric weight there is not much left, single-chip microcomputer makes buzzer warning, and when depositing electric weight and be zero, single-chip microcomputer cuts off current supply circuit by relay.

The utility model has the advantages that: because the element that control circuit adopts is few, and the mechanical counter in the induction meter can save, so cost can be low than the microcomputer digital kilowatt-hour meter; Because being the revolution at scale, the metering of power consumption carries out, so can reach the precision of former induction meter and measure reliability; Owing to adopt clock and data to preserve chip, also preserve necessary data for a long time so can charge by different multiple charge rates; Because electric card must be bought from power supply administration, so have planned supply and use of electric power and pre paid functionality.

Below in conjunction with drawings and Examples the utility model is elaborated.

Fig. 1 is a control circuit schematic diagram of the present utility model.

The utility model is made up of induction meter and control circuit, and original mechanical counter can be save in the watt-hour meter.Be contained in that control circuit in the watt-hour meter is preserved chip U2,74LS164 string and conversion chip U5, display led by direct supply shown in Figure 1, reserve battery BAT, function key KEY, hummer BUZZER, photoelectric sensor OP, 89C2051 single-chip microcomputer U1, electricity card (be the AT240C2E2ROM chip, draw among the figure), electric card reader IC CARD, 8583E2ROM data and the cut-off relay REL that is serially connected in the current supply circuit forms.Wherein:

Civil power is after transformer TF isolates, through rectifier BRIGE rectification and 8705 voltage stabilizer voltage stabilizings, the 5V direct supply that controlled circuit is required.Photoelectric sensor OP is contained in the scale place of induction meter, and its output meets the interruption pin INT0 of single-chip microcomputer U1.Function key KEY meets another interruption pin INT1 of single-chip microcomputer U1, data terminal SDA, the clock end SCL of electricity card reader IC CARD and data preservation chip U2 meets input and output pin P1.0 and the P1.1 (OC door) of single-chip microcomputer U1 respectively, since both data terminal and connect, clock end also and connect, therefore sheet choosing end 1 pin of electric card reader IC CARD is put low level, data are preserved sheet choosing end 3 pin of chip U2 and put high level, make single-chip microcomputer U1 that different device identification addresses be arranged.The power end VCC that data are preserved chip U2 meets reserve battery BAT, the input and output pin P3.7 of single-chip microcomputer U1 meets hummer BUZZER by MC1413 driver U4, the input and output pin T1 of single-chip microcomputer U1 (is the P3.5 pin, it is used for the I/O mode) meet cut-off relay REL by transistor T 2, the serial port RXD of single-chip microcomputer U1, the serial shows signal of TXD output becomes eight bit parallel data-signal Q0～Q7 by string and conversion chip U5, connect the segment data mouth of six figure place sign indicating number tube display LED again through eight transistors (not drawing among the figure), input/output port P1.2～P1.7 of single-chip microcomputer U1 connects the bit data end of each charactron of display respectively through driver U4.

Data are preserved the RAM that the 256B capacity is arranged among the chip U2, can dynamically preserve current date, time, high ebb beginning and ending time, important informations such as multiple charge rate, consumption and dump energy, the pps pulse per second signal CLOCK that one of its INT pin output was used for the alignment time, adjust tunable capacitor CY, can obtain accurate clock CLOCK signal.

Narrate principle of work below:

Insert the electricity card among the electric card reader IC CARD and when pressing function key KEY, can cause the negative saltus step of INT1 pin of single-chip microcomputer U1, and enter the INT1 interrupt routine, single-chip microcomputer reads in the electricity card with serial mode to be put down in writing for information about, and deposit this information in data and preserve among the chip U2, after this write back fail message to the electricity card.When the scale of induction meter in the user power utilization process rotates, aperture on the scale moves past photoelectric sensor OP, photoelectric sensor OP just output electric pulse signal SIG gives single-chip microcomputer U1, single-chip microcomputer U1 just at first adds up the umber of pulse computing, promptly calculate power consumption, then preserve information such as taking out the time on date the chip U2, calculate dump energy, at last institute's power consumption and dump energy are write back among the data preservation chip U2 by different periods and rate from data.By the 5V DC power supply, when the electric system temporary interruption, battery BAT preserved chip U2 power supply by diode D2 to data, to prevent the loss of data among its RAM when data preservation chip U2 was flat.When dump energy not for a long time, single-chip microcomputer U1 just goes out high level BEE signal by the P3.7 human hair combing waste, drives the hummer BUZZER sound that gives a warning by driver U4, to remind the user.Press function key KEY and can remove warning.When electric weight that the user purchases exhausted, single-chip microcomputer U1 went out low level RELY signal from the T1 human hair combing waste, made relay R EL adhesive by transistor T 2, cut off user's current supply circuit.

When under plug-in card not or electricity card failure conditions, pressing function key KEY, the serial port of single-chip microcomputer U1 and input/output port P1.2～P1.7 will light six figure place sign indicating number tube display LED in turn, and page turning shows relevant datas such as dump energy, total power consumption, current date time, multi-period beginning and ending time, multiple charge rate.

In addition, for improving the reliability of control circuit, also set up the single-chip microcomputer that constitutes by 555 timer chip U3 and transistor T 3 to reset and prevented deadlock WDOG circuit, wherein: the output terminal Q of timer U3 meets the resetting pin RST of single-chip microcomputer U1, the input and output pin T0 of single-chip microcomputer U1 (is the P3.4 pin, it is used for the I/O mode) connect the base stage input of transistor T 3, the emitter-base bandgap grading of transistor T 3 connects the 5V power supply, and collector output meets the input pin THR of timer U3.When single chip microcomputer halt or start, transistor T 3 ends, and the Q pin output vibration square wave of timer U3 is given the resetting pin of single-chip microcomputer U1, and single-chip microcomputer is resetted.During the single-chip microcomputer operate as normal, its software is constantly exported negative pulse to the base stage of transistor T 3 at the point of fixity of program from the T0 pin of single-chip microcomputer, make the T3 conducting, so the 5V power supply charges to capacitor C T by diode DX, DY and transistor T 3, keeping the THR input pin of timer U3 is high level, causing the Q pin of timer U3 is low level, thereby has guaranteed the operate as normal of single-chip microcomputer U1.

Claims (2)

1. multiple charge rate electric card type watt-hour meter, comprise induction meter and control circuit, it is characterized in that: described control circuit is preserved chip, string and conversion chip, display by direct supply, reserve battery, function key, hummer, photoelectric sensor, the mechanical, electrical card of monolithic and electric card reader, clock and data and the cut-off relay that is serially connected in the current supply circuit is formed, wherein:

Photoelectric sensor is contained in the scale place of induction meter, its output connects an interruption pin of single-chip microcomputer, function key connects another interruption pin of single-chip microcomputer, the electricity card reader, clock and data preservation both data terminals of chip and clock end connect two input and output pin of single-chip microcomputer respectively, clock and data are preserved the power supply termination reserve battery of chip, an input and output pin of single-chip microcomputer connects hummer, another input and output pin of single-chip microcomputer connects the control end of cut-off relay, the serial port of single-chip microcomputer connects the segment data mouth of display through string and conversion chip, and the input/output port of single-chip microcomputer connects the bit data end of display.

2. multiple charge rate electric card type watt-hour meter as claimed in claim 1, it is characterized in that: comprise also in the described control circuit that the single-chip microcomputer that is made of timer and transistor resets and prevents the deadlock circuit, wherein: the resetting pin of the described single-chip microcomputer of output termination of timer, an input and output pin of described single-chip microcomputer connects this transistorized input, and this transistorized output connects the input pin of timer.