GB2077932A - Electronic maximum demand meters - Google Patents

Abstract

An electronic maximum demand electricity meter containing a microcomputer has a plurality of display windows (5, 6 and 7) and switching elements (8, 9 and 10), a lead-sealable switching element (9) serves for resetting the maximum, a second switch element (8) is in one mode, a selector switch actuation of which causes display of associated data in display windows (6, 7) and display of the associated identification symbol (5) in a further display window (5), the second mode is selected by lead-sealable pushbutton 10 actuation of which causes pushbutton 8 to operate via an integral circuit to alter the programming of the microcomputer. <IMAGE>

Description

SPECIFICATION Electronic maximum demand meters This invention relates to electronic maximum demand meters.

German Published Patent Application No.

DE 2 630 608 A discloses an electronic maximum demand meter having a plurality of display windows for maximum or instantaneous values, for the accumulated highest maxima and for the number of resettings, and having a plurality of switching elements of which at least one can be lead-sealed and of which a first is provided for periodic resetting by hand of the maximum which has been run up and a second is formed as a selector switch for the display. Such maximum demand meter is in the form of an accessory device which can be fitted to an electricity meter.

The described device is provided with a switch which can be lead-sealed, for manual resetting on a monthly basis. In addition, it is possible for the maximum demand meter to be reset by an incorporated clock, a ripple control device or timing mechanism.

There exists a need to be able to provide for setting of the data when the meter is first put into operation, and further possibilities such as calculating various maxima values and other useful elements for measuring energy consumption.

According to the present invention there is provided an electronic maximum demand meter having a plurality of display windows for maximum or instantaneous values, for the accumulated highest maxima and for the number of resettings, and having a plurality of switching elements of which at least one can be lead-sealed and of which a first is provided for periodic resetting by hand of the maximum which has been run up and a second is formed as a selector switch for the display, wherein a further lead-sealable switching element is provided in the form of a pushbutton for the input of programs and values which are to be set or amended by means of a microcomputer contained in the maximum demand meter, and wherein the pushbutton is logically connected to a pushbutton of the selector switch.

A maximum demand meter embodying the invention and described hereinbelow can be programmed in a simple manner for different setting and computing programs, by pressing buttons, and the programming thereof can be altered at any time without extraneous auxiliary means.

The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a maximum demand electricity meter embodying the invention; and Figure 2 is a schematic functional circuit diagram of the meter.

Figure 1 shows a maximum demand electricity meter which can be disposed in a particular housing or in a housing which can be screwed in known manner on to a terminal block of an electricity meter. A cover panel 1 of the maximum demand meter can be secured on the actual maximum demand meter by means of screws 2.

Formed in the cover panel 1 is a window 3 in which there are arranged an instrument dial 4 with three display windows 5, 6 and 7, respective first, second and third pushbuttons 9, 8 and 10 and display lamps 11 and 1 2. The second pushbutton 8 can be freely operated while the first and the third pushbuttons 9 and 10 can perform their actions only after a coverable lead seal on respective rotary knobs 1 3 and 14 has been released.

Also provided on the dial 4 are designations on which are marked meter constants, type numbers, etc. Further designations are disposed in lines below the display windows 5, 6 and 7, and such designations respectively denote information associated with the windows above each thereof.

The column below the display window 5 sets forth identification symbols which are associated with individual displays desired. Each two pieces of information which are displayed together are arranged in a line with the respective associated identification symbol in the first column. In this way, they can be called off or amended in a neat and easily understandable manner, as will be described hereinafter.

Figure 2 is a schematic circuit diagram showing an input/output logic unit 1 5 of the electronic maximum demand meter, with the first, second and third pushbuttons 9, 8 and 10, a display means 16 with the display windows 5, 6 and 7, a microcomputer 1 7 and a non-volatile memory 1 8.

The input/output logic unit 1 5 has inputs 1 9 for receiving input data from the outside, for example by means of a ripple control receiver, and outputs 20 for connection, for example, to a telemetering section. The unit 1 5 is also connected by means of control lines 22 to a central control line 21. The display means 16, the microcomputer 1 7 and the non-volatile memory are also connected to the central control line 21 by means of further control lines 23, 24 and 25.

The maximum demand meter shown in Figures 1 and 2 operates in the following manner.

The microcomputer 1 7 installed in the maximum demand meter performs various computations and performs the functions required to display the results. The second pushbutton 8, which is for instruction input into a programming circuit of the microcomputer 1 7, normally acts as a selection switch for the displays. In this mode of operation, the values set forth in the lines below the display windows 5, 6 and 7 are call up by the microcomputer 1 7, by actuation of the second pushbutton 8, and transmitted by the microcomputer 1 7, by way of the central control line 21 and the control line 23, to the display means 16 where they are displayed. In a second mode of operation, the second pushbutton 8 can also be used for programming the maximum demand meter and for data input.This presupposes that the third pushbutton 10 which acts as a programming switch has been actuated beforehand, after removal of the lead sealing on the rotary knob 14. The second pushbutton 8 therefore performs a dual function. The second and third pushbuttons 8 and 10 are preferably in the form of touch switches.

Normally, the program in the line bearing the identification symbol 1 below the display window 5 is switched in. With that program, the identification symbol 1 is displayed in the display window 5, the maximum consumption or power Pmax is displayed in the display window 6 and the present consumption or power is displayed in the display window 7, with the display lamp 11 being lit when power measurement is operative. If another display is desired, for example a display check, the second pushbutton 8 is touched a suitable number of times for the order input into the microcomputer 17 of the maximum demand meter. The display window 5 displays the identification symbol 8 for that program and for example the display '8' appears at all positions in the two display windows 6 and 7.All the lamps 11 and 12 are also lit This indicates that the display is functioning satisfactorily.

When calling up the other pairs of values which are designated by identification symbols 2 to 5 in the lines below the display windows 5, 6 and 7, the data which, after processing in the microcomputer 17, are stored in its memory or in the non-volatile memory 18, are called up after touching the second pushbutton 8 a suitable number of times and displayed in the display means 16 by the microcomputer 17, by way of the central control line 21 and the control line 23. In that case, one of the two display lamps 1 2 indicates the tariff. If a display is required in respect of energy consumption on tariff I or tariff II respectively, the second pushbutton 8 can be suitably touched, for suitable programming of the microcomputer 1 7. The symbol 5 appears in the display window 5.The display window 6 displays the display I for the respective tariff and the display window 7 indicates the associated power consumption. After further actuation of the second pushbutton 8, the symbol 5 remains in the display window 5, tariff II appears in the display window 6, and the associated power consumption appears in the display window 7.

For the initial input of the necessary data after the maximum demand meter is connected to a consumption meter and amendment to the program, the second pushbutton 8 and the third pushbutton 10, which two buttons are logically connected, are actuated as a selector switch and as a program switch respectively. In this mode of operation, the input by the second pushbutton 8 becomes effective only after the third pushbutton 10 has been previously actuated. For example, the initial time input after the maximum demand meter is connected to an electricity meter can be effected in such a way that the second pushbutton 8 is first actuated once, whereupon the identification symbol 2 appears in the display window 5. The third pushbutton 10 which acts as a program switch is then touched once.The first, highest decimal place for the time display in respect of the days of the month which have elapsed is inputted by actuating the second pushbutton 8 a suitable number of times. That number is displayed in the display window 6, at; the highest decimal place, and a zero appears in the next following decimal place if the third pushbutton 10 has been pressed. This causes the operator to effect input, as may be required, in respect of the next decimal place. This is effected as in the case of the first decimal place. The subsequent single actuation of the third pushbutton 10 transfers the decimal places in respect of the days of the month into the nonvolatile memory 1 8, with the assistance of the microcomputer 1 7.

Input of the respective number for the present month occurs in the same manner. In each case, input of the desired number is concluded by actuation of the third pushbutton 10 so that it is unlosably stored in the non-volatile memory 1 8.

When providing for input of the energy consumption with the identification symbol 5, once again, depending on the respective tariff I or II desired, the second pushbutton 8 zan first be actuated a suitable number of times, before the third pushbutton 10 which acts as a program switch is touched for the first time, in order to change the information in the respective line in question.

Cumulation/resetting of the consumption values which have been run up, such cumulation to be effected by hand, can periodically be effected, as is known, after releasing the lead sealing on the rotary knob 13, by single actuation of the first pushbutton 9 which triggers the corresponding order for the microcomputer 1 7 for transferring the cumulated value into the nonvolatile memory 18. In this way, the maximum average values for 1 2 months can be stored.

The microcomputer may also be programmed in various ways. For example, each maximum may be formed after a respective period of 30 minutes.

However, calculation of the maximum may also be effected in overlapping periods of 30 minutes, in each case after for example 6 minutes in respect of the 30 minutes elasped (rolling maximum formation).

The information noted on the dial plate 4 in Figure 1 can be enlarged as required, if further information is desired. It will be appreciated that the microcomputer 1 7 must also be suitably programmed in that case. Thus, information relating to the particular tariffs can be set out in a plurality of lines, instead of in only one line.

Furthermore, additional lines can be reserved for further information which may be required. The number of identification symbols will be appropriately increased in that case. In any event.

the second and third pushbuttons 8 and 10 must always be actuated together in the abovedescribed manner for initial input and for amendment to the data in question.

The above-described maximum demand meter therefore does not require an additional device which is separated from the meter at least from time to time, forjnitial input of data and for amendment to the data and programs. Fitting to the respective meter for which the maximum demand meter device is intended is a simple and safe operation, and this is also reflected in the maximum demand meter being of an advantageous price.

Claims (6)

1. An electronic maximum demand meter having a plurality of display windows for maximum or instantaneous values, for the accumulated highest maxima and for the number of resettings, and having a plurality of switching elements of which at least one can be lead-sealed and of which a first is provided for periodic resetting by hand of the maximum which has been run up and a second is formed as a selector switch for the display, wherein a further lead-sealable switching element is provided in the form of a pushbutton for the input of programs and values which are to be set or amended by means of a microcomputer contained in the maximum demand meter, and wherein the pushbutton is logically connected to a pushbutton of the selector switch.

2. A meter according to claim 1, wherein the pushbutton of the selector switch has a double function and for this purpose is connected to a display circuit means and to a programming circuit means in the microcomputer.

3. A meter according to claim 1 or claim 2, wherein the pushbutton of the selector switch is operative for the input of data and programs only after actuation of the pushbutton of the further switching element.

4. A meter according to claim 1, claim 2 or claim 3, wherein said two pushbuttons are in the form of touch switches.

5. A meter according to any one of claims 1 to 4, wherein actuation of the pushbutton of the selector switch can cause the display of associated data in two display windows, while an associated identification symbol is displayed in a further display window.

6. An electronic maximum demand meter substantially as herein described with reference to the accompanying drawing.