CN2174711Y

CN2174711Y - Intelligent multi-function digital electric meter

Info

Publication number: CN2174711Y
Application number: CN 94200017
Authority: CN
Inventors: 闻立业
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-04-27
Filing date: 1994-01-04
Publication date: 1994-08-17
Anticipated expiration: 2004-01-04

Abstract

The utility model relates to a counter for the quantity of electricity usage, which relates to an intelligent multi-function digital electric meter. The purposes of the intelligent multi-function digital electric meter are in order to reduce loss, increase precision and sensitiveness, prevent electric stealing and leakage, automatically control the quantity of electricity usage of consumers and achieve to automatically pay for the electric charge. The intelligent multi-function digital electric meter mainly comprises the components of a core SCM, an electricity measure circuit, the circuits of a digital display circuit, an electricity stealing-leakage circuit, a fault examination circuit and a sound-light alarm circuit, which are all connected with the core SCM, an electricity erasable programmable memorizer EEPROM, an external insert typed electric card which is disposed by software and hardware, etc. The power supply department stores the quota of electricity usage in the electric card in order to sell to the consumers. When the quota in the electric card is finished, the intelligent multi-function digital electric meter can automatically cut the power source off in order to require the consumers to buy and exchange the electric card.

Description

Intelligent multi-function digital electric meter

The utility model relates to the power consumption measuring apparatus, a kind of intelligent type multi-function digital watt-hour meter.

The watt-hour meter that generally adopts (as DD9 series watt-hour meter) all is the mechanical type ammeter that adopts the electromagnetic interaction principle to realize at present, has following several problem: 1. easily by stealing; 2. to the restriction of user's electric weight of no use; 3. sensitivity and precision are low; 4. the loss of ammeter own is big; 5. there is not creepage protection function; 6. power supply department need organize the special messenger to visit to check meter and collect the electricity charge.

The purpose of this utility model is that a kind of intelligent type multi-function digital watt-hour meter will be provided, and reduces electric energy loss, improves measuring accuracy and sensitivity, prevents the stealing electric leakage, saves power supply department electricity bill control manpower, helps carrying out computing machine and manages automatically.

The purpose of this utility model realizes as follows: Intelligent Digital formula watt-hour meter is made up of five key links that the core single-chip microcomputer links with it; 1. electric degree measurement links; 2. electric degree writes down link (also claiming the electricity card); 3. electric degree shows link; 4. stealing detection of electrical leakage and sound and light alarm link; 5. emergency protection link.Its theory diagram as shown in Figure 1.

This intelligent type multi-function digital watt-hour meter comprises the holding circuit of being formed the electricity card of the smart circuit of measuring power consumption, outside plug type recording user power consumption, being shown the digital display circuit of electricity card residue power consumption index, be made up of stealing, electric leakage, overvoltage, under-voltage, overcurrent, short-circuit detecting circuit and sound and light alarm and control with charactron by single-chip microcomputer; Current measurement circuit links to each other with single-chip microcomputer through A/D by analog switch with tension measuring circuit, power-factor measurement links to each other with single-chip microcomputer, in addition, single-chip microcomputer also links to each other with the electricity card, electric degree shows and also links to each other with single-chip microcomputer, single-chip microcomputer also links to each other with stealing, electric-leakage detection circuit, and is connected with the sound and light alarm signal to warning circuit and fault secure circuit; Described smart circuit mainly is made up of single-chip microcomputer (80C31), data latches (74HC373), memory under program (EPROM27C64) and outside plug type electricity card (EEPROM2817A or EEPROM2864); Described outside plug type electricity card adopts EEPROM(2817A or 2864); Described 4-digit number display circuit is made up of charactron (LA5011) and driver (74HC164); Holding circuits such as described stealing, electric leakage, overvoltage, under-voltage, overcurrent and short circuit are made up of current transformer, single-chip microcomputer, three-phase pipe, light emitting diode, hummer and relay.

The smart circuit of this table is mainly connected to form by single-chip microcomputer (80C31) and memory under program (EPROM 27C64) (accompanying drawing 3) and outside plug type electricity card (EEPROM 2817A or EEPROM 2864).By measuring voltage, electric current and power factor, calculate power consumption by single-chip microcomputer, see accompanying drawing 2.The output of voltage measurement resistor voltage divider circuit is exported by same analog switch (4052) and operational amplifier A 1(OP07 with the current measurement shunt), link to each other with single-chip microcomputer through operational amplifier A 2 on the one hand, constitute phase comparator with operational amplifier A 3 and measure power-factor angle; Link to each other with single-chip microcomputer with analog to digital converter (A/D) (accompanying drawing 5) through ac-dc conversion circuit (AC/DC) on the other hand, calculate the effective value of electric current, voltage, and then calculate power consumption.

The record link of this table adopts 2817A to handle through software and hardware and makes outside plug type electricity card, power supply department deposits power consumption index in the electricity card and is sold to the user, the user is inserted in the electricity card in the watt-hour meter jack, make it to be communicated with single-chip microcomputer, (accompanying drawing 4 is electricity card and single-chip microcomputer connection layout), ammeter energized is voluntarily powered to the user.Single-chip microcomputer deducts power consumption to power consumption index in the electricity card, and when power consumption index in the electricity card was reduced to zero, single-chip microcomputer sent instruction, cuts off user's power supply, thereby realizes the function of volitional check power consumption.When power consumption index in the electricity card near zero the time, ammeter sends signal, reminding user to replace electricity card.Power supply department is regained used electricity card, writes power consumption index again, can sell.So just exempt the special messenger of power supply school and visited from door to door to check meter and collect the electricity charge, saved lot of manpower and material resources.This type electricity card can use 100,000 times repeatedly, so cost is extremely low.

The demonstration link of this watt-hour meter constitutes 4 bit digital display circuits by charactron and driver thereof, (accompanying drawing 6).Show residue power consumption index in the electricity card according to the mode that counts down, and available knob control display circuit, to reach the purpose that reduces the ammeter own loss.

Be provided with current transformer in this table, can measure the out-of-balance current of stealing, electric leakage (comprising that the person gets an electric shock) generation delicately; Its tension measuring circuit also can be measured superpotential, under-voltage; current measurement circuit can also be measured overload; when these faults take place; single-chip microcomputer is controlled the alarm and protection circuit (seeing accompanying drawing 7) that hummer, light emitting diode and relay are formed respectively by triode T1, T2, T3; send alerting signal; cut off the electricity supply simultaneously, with protection consumer electronics and personal safety.

Accompanying drawing 2～accompanying drawing 7 is embodiment of the present utility model.Below in conjunction with accompanying drawing this watt-hour meter principle is further described.Accompanying drawing 3 is single-chip microcomputer line graphs.Single chip circuit mainly is made up of single-chip microcomputer (80C31), latch (74HC373) and memory under program (27C64), and the measurement of power consumption, calculating and control supervisor all are stored in the memory under program.

Accompanying drawing 2 is electric degree measurement links circuit diagrams.On the one hand, resistance R 1, R2 bleeder circuit and shunt FL and analog switch (4052) constitute voltage, current sampling circuit, sampled signal is through operational amplifier A 1(OP07) amplify after, by ac-dc conversion circuit (AC/DC), be transformed into electric current, voltage the proportional simulating signal of the value of putting (seeing accompanying drawing 5) is arranged, (MC14433) is transformed to digital signal through high-precision a/d converter, calculated the effective value of voltage, electric current by single-chip microcomputer; On the other hand, voltage signal and current signal are through operational amplifier A 2(LM324) be shaped as the square-wave pulse of standard, with operational amplifier A 3 output signals relatively, calculate power factor by single-chip microcomputer.Single-chip microcomputer adopts numerical integration method according to voltage, electric current and power factor value, calculates power consumption.

The electricity card adopts 2817A to be processed into the external plug-in pattern through software and hardware, and itself and single-chip microcomputer line are as shown in Figure 4.Electric degree shows that link mainly constitutes 4 bit digital display circuits by charactron (LA5011) and driver (74HC164), its line as shown in Figure 6, with last power consumption index in the mode explicit user electricity card that counts down.By the button control display circuit, do not work at ordinary times, to reduce the table internal loss.

Accompanying drawing 7 is stealing, detection of electrical leakage and sound light alarming circuit.When stealing, electric leakage take place when, current transformer HG can measure the out-of-balance current signal between power firestreak and the ground wire in time, send into single-chip microcomputer through current measurement circuit, single-chip microcomputer sends instruction, send the sound and light alarm signal by the control of triode T2, T3, pass through triode T1 pilot relay J adhesive, disconnect user power supply simultaneously.

In addition, when faults such as electrical network generation superpotential, under-voltage and ammeter overload, utilize the measuring-signal of voltage, electric current, single-chip microcomputer sends instruction, cuts off user's power supply, with the safety of protection user household electrical equipment.

Claims

1, a kind of intelligent type multi-function digital watt-hour meter is characterized in that: this table comprises the holding circuit of being formed the electricity card of the smart circuit of measuring power consumption, outside plug type recording user power consumption, being shown the digital display circuit of electricity card residue power consumption index, be made up of stealing, electric leakage, overvoltage, under-voltage, overcurrent, short-circuit detecting circuit and sound and light alarm and control with charactron by single-chip microcomputer; Current measurement circuit links to each other with single-chip microcomputer through A/D by analog switch with tension measuring circuit; power-factor measurement links to each other with single-chip microcomputer; in addition; single-chip microcomputer also links to each other with the electricity card; electric degree shows and also links to each other with single-chip microcomputer; single-chip microcomputer also links to each other with stealing, electric-leakage detection circuit, and is connected with the sound and light alarm signal to warning circuit and fault secure circuit.

2, intelligent type multi-function digital watt-hour meter according to claim 1 is characterized in that: described smart circuit mainly is made up of single-chip microcomputer (80C31), data latches (74HC373), memory under program (EPROM27C64) and outside plug type electricity card (EEPROM2817A or EEPROM2864).

3, intelligent type multi-function digital watt-hour meter according to claim 1 is characterized in that: described outside plug type electricity card adopts EEPROM(2817A or 2864).

4, intelligent type multi-function digital watt-hour meter according to claim 1 is characterized in that: described 4-digit number display circuit is made up of charactron (LA5011) and driver (74HC164).

5, intelligent type multi-function digital watt-hour meter according to claim 1 is characterized in that: holding circuit such as stealing, electric leakage, overvoltage, under-voltage, overcurrent and short circuit is made up of current transformer, single-chip microcomputer, three-phase pipe, light emitting diode, hummer and relay.