DE1055119B - Compensation circuit for testing power, current and voltage meters according to the voltage sum compensation method - Google Patents

Description

The subject of the main patent application L 29294 VIIIc / 21e is a compensation circuit for testing of power, current and voltage meters, where the voltage to be compensated is the sum is the voltage drop across the normal resistance and the divider resistance of the voltage circuit and the The sum of the voltage drops at the normal resistance and at the divider resistance of the voltage circuit is constant is.

Such a circuit arrangement is shown in principle in FIG.

1 with a step compensator is referred to, which contains a designed as a graduation selector compensation resistor 2, which has, for example, fifteen taps. The auxiliary battery is labeled 3. To set the prescribed auxiliary current / the EMF of a normal element E _{n is} switched to the resistors 5, 6 via the measuring button 4 and the variable resistor 7 is set so that the galvanometer 8 is de-energized. 9 is a full scale selector. The desk

10 is set to the type of instrument to be tested. In L , power meters are tested according to the voltage sum compensation method, the graduation selector and the full scale selector 9 not being used. In this case, a special Narmal resistor 11 is used, which is designed as a 15-part graduation selector and works together with a full-scale selector 12. Furthermore, a series resistor 13 is provided for the galvanometer circuit, which is switched over together with the normal resistance in order to be able to read the error or the correction of the power meter from the deflection of the galvanometer 8 in a known manner for all test points. If, for example, a 100-part power meter 14 is to be tested, the full-scale value selector 12 must be set to "100". The taps "100" to "10" of the graduation selector 11 are used to check the individual tick marks. The normal resisted

11 is only suitable for a certain nominal current in this training.

The measurement of current, voltage and power meters according to the usual compensation method takes place in the positions St, Sp of the switch 10. For testing current and power meters according to the usual compensation method, a normal step resistance would still be required. In addition, a special normal resistor with appropriately the same dimensions and terminal arrangement, as shown at 11, would then be required for the power meter test using the voltage sum compensation method. If necessary, this would have to be against the compensation circuit
for testing performance,
Ammeters and voltmeters
according to the voltage sum compensation method

Addition to patent application L 29294 VIHc / 21 e
(Interpretation document 1 050 897)

Applicant:

LICENTIA Patent-Verwaltungs-G.m.b.H., Hamburg 36, Hohe Bleichen 22

Gerhard Busse, Berlin-Tempelhof,
has been named as the inventor

the first-mentioned normal step resistance must be exchanged. Apart from this inconvenience that would mean an additional purchase of the special normal resistor 11. To this one To avoid the disadvantage, according to the invention, the normal resistance as a graduation selector and as a step normal resistance educated. This means that the current and power meter tests are carried out according to the usual Compensation method for nominal currents from 0.2 to 10 A and the power meter test according to the voltage sum compensation method by adding a single device to each other United To furthermore the power meter test according to the voltage sum compensation method To be expanded for further rated currents, a further training is accordingly a switchable A secondary resistance is provided for the normal resistance.

The invention is explained in more detail with reference to FIG. 2, in which, for the sake of clarity, only the combined normal resistance is shown with its associated elements. Same elements have the same numbers as in Fig. 1.

The normal resistor 11 is provided on the one hand with the right taps 0.2 to 10 A and on the other hand with the left-hand taps 10 to 150 A. If the first-mentioned connections are used, then> the normal resistor 11 acts as a normal step normal resistor for testing power and Ammeters according to the usual compensation

809 ¹ 790/253

Claims (3)

drive, the switch 10 of the! Compensator 1 is then placed in the position St. The graduation selector 15 of the normal resistor 11 (FIG. 2) is set to the "ammeter" tap. The connections 16, 17 of the combined normal resistance would be connected to the terminals 18, 19 of the compensator 1 in this case. The testing of power meters according to the voltage sum compensation method is carried out by actuating the graduation selectors 15 and 12, as already described above. In general, power meters have a nominal current of S A. For testing power meters with a different nominal current, a switchable shunt resistor 20 is provided for normal resistor 11, the value of which can be changed by a plug contact. In the exemplary embodiment, three different rated currents 1, 2, 5 A are selected. Any intermediate stages can also be carried out. In order to switch to different nominal currents, series resistors can also be arranged for the normal resistor 11. When testing power meters using the total voltage compensation method, the current path 21 (Fig. 1) is always connected to terminal 22 (Fig. 2), even if the nominal current of the device under test deviates from this value. The voltage divider 23 shown in FIG. 1 and arranged in the test voltage circuit is of normal design. The divider resistor 24 for the undervoltage is expediently provided with taps, which are indicated by dashed lines. The taps are chosen so that in the case of non-integer voltages, for example U · yj, U / Ys, integer voltages are set at the resistor 25 consisting of several crank resistors, but the same voltage can always be tapped at the divider resistor 24. Due to the differently large divider resistance 24 of the voltage divider 23 in the case of integer and non-integer nominal voltages, there is a change in the closing circuit of the galvanometer circuit. This change is compensated for by the switchable resistor 26 and switch 27 (FIG. 2). Patent claims: 1. Compensation circuit for testing power, current and voltage meters, at which the voltage to be compensated is the sum of the voltage drops across the normal resistor and at the divider resistance of the voltage circuit and the sum of the voltage drops at the normal resistance and is constant at the divider resistance of the voltage circuit, according to patent application L 29294 VIIIc / 21e, characterized in that the normal resistance is designed as a graduation selector and as a step normal resistance. 2. Compensation circuit according to claim 1, characterized in that a switchable Shunt or series resistor to the normal resistor is provided. 3. Compensation circuit according to claim 1 or 2, characterized in that the voltage divider (23) designed for measuring integer voltages is provided with taps arranged on the divider resistor (24) in such a way that when non-integer voltages (U · γι, UjYz ) at the divider and setting it to integer voltages at the taps for the integer and integer nominal voltages, the same partial voltage can be removed and that a switchable resistor (26) is arranged in series with the normal resistor, which keeps the resistance of the galvanometer circuit constant. 1 sheet of drawings