DE19833046A1 - Electricity meter for detecting energy consumption - Google Patents

Abstract

The electricity meter has a rotor disc which rotates at a rate dependent on the energy consumption rate. The disc has a marking, which is detected by an optical pulse source (10), for providing a corresponding signal (S), that is converted into an energy signal (E) and received at a signal output (24), e.g. a signal output interface. The optical signal source may provide respective signals for two different positions of the rotor disc. An energy store (28) is provided to collect and store the energy provided at the signal output.

Description

The invention relates to an electricity meter and a Method for detecting energy consumption, one of Rotor disc is set into a rotary motion, the rotation of which speed is proportional to energy consumption.

So-called inducs are particularly useful as electricity meters tion counter and especially Ferraris counter known to Er Energy consumption is also recorded as a house stop counter can be used. With the induction counters the rotor disc via an inductive force Offset rotary movement. The speed of rotation is proportional nal to the energy consumption to be measured, which is therefore due to a scan of the speed of rotation of the rotor disk can be averaged. This is usually a pulse generator provided that generates a pulse when it hits one on the Mark attached to the rotor disc is detected or scanned continuous The scanning can be inductive, capacitive or op done table.

Energy consumption is either directly on electricity displayed counter or via a corresponding signal output (Interface) to a central registration unit telt. The so-called S0- Interface known, which is defined in DIN 43864. The S0 interface is a current interface in which the Electricity meter, especially the pulse generator, a current is fed. In the inactive state, i.e. H. if from impulse ge If no pulse is emitted, only a very high one flows low operating current up to a maximum of 2 mA via the interface. When the pulse is active, the operating current jumps the S0 interface jumped to a value between 10 and 27 mA. A current pulse is therefore generated. Everyone  Current pulse corresponds to a certain amount of energy, so that the current pulse is also referred to as an energy signal that can.

An optical pulse generator for an electricity meter is for example from the German Ausleschrift 24 47 674 be knows. The pulse generator described comprises a light emit ing diode and a phototransistor as a pulse current producer. There is a slot between the diode and the phototransistor body arranged. As soon as the light emitted by the diode a circuit is closed on the phototransistor sen and emitted a signal.

The advantage of optical pulse generators is that Scanning takes place without contact and without force. In particular, they are caused by electrical or magnetic fields the less influenceable than, for example, inductive impulse giver. However, there is energy for the optical impulse supply necessary, for example via a specially for this provided coil in the electricity meter or by a external energy supply provided for this purpose becomes.

The present invention has for its object a Electricity meter with an optical pulse generator as well as a Method of recording energy consumption to indicate where with the power supply of the optical pulse generator with poss simple means is guaranteed.

The first-mentioned object is achieved according to the invention by an electricity meter

• a) with a device for recording energy consumption, the
  • 1. a rotor disk with at least one marking and
  • 2. has an optical pulse generator for scanning the rotor and for generating a signal corresponding to the energy consumption,
• b) with a signal output for emitting one from the signal shaped energy signal, which signal output by a external electrical power supply energy is available where when it comes to energy requirements for the facility led energy is covered.

An S0 interface is preferably used as the signal output, see above that the already provided via the external power supply Energy used to supply energy for the facility will. The key advantage is that none additional energy source is necessary. An electricity counter with optical pulse generator, which has an S0 cut can therefore do without additional care operations are operated.

In a particularly preferred embodiment, the Electricity meter to collect and store energy Save the energy supplied via the signal output. This means that even with only a small amount of energy Signal output and at the same time relatively high energy consumption need of the optical pulse generator a safe operation of the optical pulse generator guaranteed.

The pulse generator preferably has one light source and one optical sensor. Light source and optical sensor are preferably designed as a light emitting diode or photoresistor. These components allow space-saving construction.

To the energy consumption of the pulse generator and the device To keep energy consumption low is a Clock generator provided with which the number of times per time unit made scanning is specified. The Läu The heel is therefore not continuous, but only after certain time intervals sampled. The light source is not switched on continuously, so that your Ener energy consumption is very low. In addition to the light source, too In addition, the optical sensor and the associated Si  signal processing are clocked. The clock generator determines whether a component of the facility is active or passive is, d. H. whether they are switched on / ready to receive.

The optical pulse generator is preferably designed such that that in at least two different places the runner disc a respective signal can be generated to an orken to enable rotation of the rotor disc.

In particular, the pulse generator has two light sources for this purpose len and two optical sensors. Instead of two light sources len can also be used a single whose beam is on two different locations of the rotor disc is directed, an optical sensor is assigned to each of these locations. As a further alternative embodiment, the turning mechanism detection on the rotor disc two different Markings attached. The markings differ for example with regard to their reflectivity or are designed differently, for example as a recess tion in and as a reflector on the rotor disk. From the temporal sequence of the signals from the two optical sensors or from the sequence of different markings determines the direction of rotation. The pulse generator only adds correct direction of rotation from a so-called pulse signal.

The electricity output is advantageously tough at the signal output lers a central registration unit connected. To this the energy consumption determined by the electricity meter need transmitted.

The second-mentioned object is achieved according to the invention by a method for recording an energy consumption with an electricity meter, in which

• a) a marked rotor in a Rotational movement is offset, the rotational speed corresponds to energy consumption,
• b) the rotor disk is optically scanned,  
• c) a signal is generated when the marking is scanned,
• d) depending on the signal, an electrical current that a signal output is supplied from the outside, for generation tion of an energy signal is modulated, and
• e) the energy requirement for carrying out steps a) to d) is covered by the energy supplied by the electricity.

The ones mentioned with regard to the electricity meter partial training and special advantages apply sensibly according to the procedure.

In a particularly useful embodiment of the process The rotor disc is used to reduce energy consumption need sampled with a predeterminable clock frequency. The Clock frequency is specified internally and can be advantageous liable design via the current supplied varies who the so that the timing, for example, from a central Registration unit is influenced from.

The clock is used to further reduce the energy requirement frequency preferred depending on the rotational speed speed of the rotor disc controlled. The speed-dependent control is based on the knowledge that the change the speed of rotation of the rotor disc of a certain Is subject to inertia and does not change abruptly can. Knowing the current speed of rotation Accordingly, the earliest possible time can be determined when the mark passes the pulse generator again. The sampling rate adapts to the needs. At a high speed speed of the rotor disk at a correspondingly high rate, with which the marking passes the pulse generator, the The rotor disk is scanned very often. At low revs On the other hand, the rotor disc rarely becomes speedy scanned.

For a simple circuit design of the clocks generation, the clock frequency is preferably kept constant.

Exemplary embodiments, further details and advantages of the invention tion are explained below with reference to the drawing. It each show in schematic representations:

Fig. 1 is a rotor disk having a marking and optical rule pulse generator,

Fig. 2 is a block diagram for a low-energy generation of an energy signal and

Fig. 3 shows an exemplary embodiment of a circuit.

In Fig. 1 a around a central axis 2 rotatably mounted rotor disc 4 is shown having a mark 6. The usual direction of rotation of the rotor disk 4 is indicated by an arrow 8 . Furthermore, an optical pulse generator 10 is symbolized by dashed lines in FIG. 1. It comprises a first and second structural unit 12 , 14 , each having a light source 16 and an optical sensor 18 , and an evaluation unit 20 . Rotor disk 4 and optical pulse generator 10 are essential features of an electricity meter 22nd

Induction or Ferraris meters are preferably used as electricity meters 22 . In such counters, a force is exerted on the rotor disk 4 via induction coils (not shown in more detail), as a result of which the rotor disk 4 is set in rotary motion. The rotary movement corresponds to the energy consumption to be detected by the electricity meter 22 .

As soon as the marking 6 passes one of the two structural units 12 , 14 , a signal S1 or S2 assigned to the respective structural unit is generated. To generate the signal S1, S2, for example, a light beam emitted by the light source 16 is reflected by the marker 6 , which then strikes the optical sensor 18 and thereby closes a circuit.

The two units 12 , 14 are used to detect the direction of rotation of the rotor disk 4th For this purpose, the signals S1, S2 are compared in the evaluation unit 20 with regard to their chronological succession. Only in the normal direction of rotation, as indicated by arrow 8 , is a pulse signal IS generated and forwarded by the evaluation unit 20 . A pulse signal IS is emitted per revolution of the rotor disk 4 , which corresponds to a certain amount of energy consumed. To detect energy consumption without the option of detecting the direction of rotation, a single construction unit 12 , 14 with only one light source 16 and only one optical sensor 18 is sufficient. The version with only one unit 12 , 14 has the advantage of low energy consumption and a simple structure.

The pulse signal IS is passed on to a signal output 24 in which it is formed into an energy signal E. The signal output 24 is in particular a so-called S0 interface, as defined in DIN 43864 as a current interface for the transmission of impulses between an encoder and a tariff device. A slight current I flows permanently via the signal output 24 as an S0 interface. The shaping of the energy signal E is brought about by the fact that when a pulse signal IS arrives at the signal output 24, the slight current I increases suddenly for a short time.

The output energy signal E is transmitted to a central acquisition unit 25 , from which the energy consumption measured by the electricity meter 22 is detected, and from which control signals are optionally output to the electricity meter 22 . Preferably, a plurality of electricity meters 22 are connected in a network to a single central detection unit 25 .

The processes up to the formation of the energy signal E at the signal output 24 are explained in more detail with reference to the block diagram according to FIG. 2. The signal output 24 from the outside, ie from outside the electricity meter 22 , via the connections 36 A, 36 B supplied current I is fed via a current limiter 26 to an energy store 28 . In the energy store 28 , the energy supplied by the current I is collected and stored. With the energy store 28 , the light source 16 , shown as a light emitting diode, the opti cal sensor 18 , a clock generator 30 and an evaluation unit 32 is connected. These units obtain the energy for their own use exclusively from the energy that is supplied via the signal output 24 . In particular, they obtain the necessary energy from the energy store 28 .

As soon as light from the light source 16 hits the optical sensor 18 , a signal S is forwarded to the evaluation unit 32 . This in turn forwards a pulse signal IS to the signal output 24 , where it is formed into an energy signal E, which is emitted to the outside. The optical pulse generator 10 for generating the pulse signal IS accordingly comprises the light source 16 , the optical sensor 18 and the evaluation unit 32 .

The current limiter 26 serves to ensure that the current claimed by the circuit never exceeds, for example, 2 mA, so that the energy signal E emitted at the signal output 24 is not influenced and is as undistorted as possible.

In addition to the energy storage 28 , the clock generator 30 is an essential functional element. This means that the optical pulse generator works independently of an additional energy supply. The clock generator 30 acts both on the light source 16 and on the optical sensor 18 and on the evaluation unit 32 . The clock generator 30 specifies the times at which the rotor disk 4 is scanned. The generation of the signal S and its processing to the pulse signal IS in the evaluation unit 32 therefore only takes place at certain times when the individual components are activated by the clock generator 30 .

There are various options for choosing the clock frequency. In terms of circuitry, the easiest way to achieve a constant timing. The clock frequency should be chosen so high that it is ensured that the mark 6 is scanned with each revolution. This can be achieved, for example, by calculating the shortest possible dwell time of the marking on the optical sensor 18 at a known maximum rotational speed and in the known extension of the marking, after which the clock frequency is determined. This should be so high that the marking can be scanned at least twice during the shortest possible dwell time.

The energy consumption of the optical pulse generator 10 can be significantly reduced if the clock frequency is adapted to the rotational speed of the rotor disk 4 . For this it is necessary that the chronological sequence of the signals S that have already been detected is recorded. Due to the inertia of the rotor disc in induction meters, the speed of rotation cannot change abruptly. From the rotational speed and the point in time of the last detected signal, the earliest possible point in time at which the marking next passes the light source 16 can thus be determined.

A preferred embodiment of a circuit is shown in detail in FIG. 3. For a better overview, the functional blocks according to the block diagram of FIG. 2 are indicated by dashed lines. According to the circuit diagram, the current I provided externally at the signal output 24 is fed to the current limiter 26 . This has a diode D1 at its input, which ensures that no current I flows back to the signal output 24 . It also prevents energy stored in the energy store 28 from flowing off if the signal output 24 is short-circuited. The current limiter 26 also has a transistor T1 and a resistor R1 as well as a transistor T2 and a resistor R2, the first transistor-resistor pair serving as a current limit for the energy store 28 and the second pair serving as a current limit for the downstream circuit. The current limiter 26 additionally has a capacitor C3 and a resistor R3 in a parallel circuit.

The adjacent to the current limiter 26 Energiespei cher 28 is formed by a resistor R4 and a series-connected capacitor C4, which is connected to a basic potential G.

The light source 16 is shown as a light emitting diode and the optical sensor 18 as a phototransistor. The two components receive their energy from the energy store 28 or directly from the current limiter 26 . They form a common structural unit, which is referred to as an optoconverter 34 . From the opto-converter 34 , the signal S is generated and forwarded.

The clock generator or clock generator 30 , which specifies the clock for both the light source 16 and the optical sensor 18 according to this exemplary embodiment, is formed by the resistors R5, R6 and the capacitors C5, C6 and by an integrated circuit IC1 with the commercial Chen designation ICM7556. Such a circuit is usually used as a so-called timer circuit. The clock generator 30 only releases the circuit at certain times, so that it can only consume energy at times. For this purpose, it emits a clock signal TS.

According to FIG. 3, the evaluation unit 32 comprises a signal processor 32 A and a comparator 32 B. In the signal processor 32 A, the resistors R7, R8, the transistor T8 and the capacitor C8 form an output amplifier for the clock generator 30 . In order to stabilize the output signal S of the opto-converter 34 and to adapt it to the requirements of the downstream comparator 32 B, a so-called Z-diode D9, resistors R9, R10 and a resistor R11 and a capacitor C11 are provided, the latter being at the basic potential G. .

The comparator 32 B primarily comprises an integrated circuit IC2 with the commercial designation ICM7556 as well as a resistor R12 and two capacitors C12, C13. The clock signal TS from the clock generator 30 is present at the input with the number 8 of the IC2 and the signal S from the opto-converter 34 is present at the input with the number 12. The comparator 32 B compares the two signals TS, S with each other and only then passes a pulse signal IS to the subsequent signal output 24 if it is ensured that the marking 6 of the rotor disk 4 has passed the optoconverter 34 exactly once.

As a rule, the marking 6 is scanned several times by the opto-converter 34 during a run. A signal S is generated in each case. A plurality of successive signals TS, S from the clock generator 30 and from the optoconverter 34 therefore run in at the comparator 32 B at the same time. After the arrival of the first signal S from the opto-converter, the comparator 32 B outputs a pulse signal IS and at the same time blocks the delivery of further pulse signals IS until it receives a clock signal TS from the clock generator 30 , which does not have a signal S from the opto-converter 34 is accompanied. This is a reliable indication that the marking 6 has passed the optoconverter 34 . The comparator 32 B is thereby enabled again until the next simultaneous arrival of a signal S and a clock signal TS.

At signal output 24 , the current I provided externally via connections 36 A and 36 B is modulated. And in such a way that the current I is briefly amplified ver in the form of a square wave signal when a pulse signal IS is applied. This square-wave signal corresponds to a unit of determination of the energy detected in the electricity meter 22 and leaves the signal output 24 as the energy signal E. The signal output 24 has the resistors R14, R15, R16, a transistor T14 and a Zener diode D14. The latter prevents the voltage at the signal output 24 from dropping below the value required to supply the circuit.

The electricity meter 22 and the method for detecting an energy consumption are based on the basic idea of using the energy provided via a signal output 24 to cover the energy requirement of the device for detecting the energy consumption in the electricity meter 22 . The electricity meter 22 is preferably designed as a Ferraris meter and the device comprises a rotor disk 4 with a marker 6 and an optical pulse encoder 10th In order to ensure safe operation of the device, even if only a relatively low energy is made available via the signal output 24 , the energy provided is collected by an energy store 28 . A clock generator 30 is provided to reduce the energy requirement of the device, so that the device is only supplied with energy at certain times. The combination of energy storage device 28 and clock generator 30 makes it possible in a particularly advantageous manner to keep the energy consumption as low as possible.

Claims (13)

1. Electricity meter ( 22 )

• a) with a device for detecting an energy consumption, the
  • 1. a rotor disc ( 4 ) with a marking ( 6 ) and
  • 2. has an optical pulse generator ( 10 ) for scanning the rotor disc ( 4 ) and for generating a signal corresponding to the energy consumption (S, S1, S2),
• b) with a signal output ( 24 ) for emitting an energy signal (E) formed from the signal (S, S1, S2), to which energy can be supplied by an external electrical power supply, the energy requirement for the device being covered by the energy supplied .

2. Electricity meter ( 22 ) according to claim 1, which has an energy store ( 28 ) for collecting and storing the energy supplied via the signal output ( 24 ). 3. Electricity meter ( 22 ) according to claim 1 or 2, in which a clock generator ( 30 ) is provided. 4. Electricity meter ( 22 ) according to one of claims 1 to 3, in which the optical pulse generator ( 10 ) is designed such that at two different locations of the rotor disc ( 4 ) a respective signal ( 51 , 52 ) can be generated. 5. Electricity meter ( 22 ) according to one of claims 1 to 4, in which the signal output ( 24 ) is designed as an S0 interface, in particular according to DIN 43864. 6. Electricity meter ( 22 ) according to one of claims 1 to 5, in which a central detection unit () is connected to the signal output ( 24 ). 7. A method for detecting an energy consumption with an electricity meter ( 22 ), in which

• a) a rotor ( 4 ) provided with a marking ( 6 ) is set into a rotational movement, the speed of rotation corresponding to the energy consumption,
• b) the rotor disk ( 4 ) is optically scanned,
• c) a signal (S, S1, S2) is generated when the marking ( 6 ) is scanned,
• d) depending on the signal (S, S1, S2), an electrical current (I), which leads to a signal output ( 24 ) from the outside, is modulated to produce an energy signal (E), and
• e) the energy requirement for carrying out steps a) to d) is covered by the energy supplied via the current (I).

8. The method according to claim 7, in which the provided by the external power supply Energy is collected and stored. 9. The method according to claim 7 or 8, in which the rotor disk ( 4 ) is scanned with a predeterminable clock frequency. 10. The method according to claim 9, in which the clock frequency via the supplied current (I) ge is controlled. 11. The method according to Ansptuch 9 or 10 , in which the clock frequency is controlled as a function of the speed of rotation of the rotor disk ( 4 ). 12. The method according to claim 9 or 10, at which the clock frequency is kept constant. 13. The method according to any one of claims 7 to 12, in which the rotor disk ( 4 ) is optically scanned at two different locations.