JPS5938667A - Apparatus for testing of winding number ratio of electromagnetic coil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a turns ratio testing device for electromagnetic coils used in transformers and the like.

[Technical background of the invention]

The number of turns of an electromagnetic coil such as a transformer often has a great influence on its functionality, and the number of turns is usually checked by various methods after the coil is completed.

FIG. 1 shows an example of a general method for measuring the induced voltage generated in a coil to confirm whether the coil has the desired number of turns. This method will be explained below.

A voltmeter 8 is attached to the primary coil 2 of the transformer under test 1, a voltmeter 9 is attached to the secondary coil 3, a voltmeter 10 is attached to the coil 4,
A voltmeter 11 is connected to the coil 5, a voltmeter 12 is connected to the coil 6, and a voltage side 13 is connected to the coil 7. Now, when a predetermined AC voltage is applied to the primary coil 2, the voltmeters 8, 9, 10, 11, and 12 show a voltage proportional to the number of turns of the coil. Therefore, the number of turns n2 of coil 2
, the number of turns of coil 3 is n3, and similarly the number of turns of each coil is n4, n5. n6 and n7, the voltage of voltmeter 8 is V8, the voltage of voltmeter 9 is V9, and similarly the voltage of each voltmeter is V10, V11, V12, V13, the following (1), (2), (3), (4), (5)
The turns ratio of the coil can be calculated and confirmed from the values of each voltmeter using the formula.

[Problems with background technology]

However, in this method, (1) an error in the deflection of the voltmeter leads to an error in the turns ratio; (2) Voltmeter reading errors lead to turns ratio errors. (3) It is difficult to understand the difference in the number of turns, which is extremely small. (4) It takes time to read the voltage side. (5) Proportional calculation is time-consuming. These disadvantages are particularly problematic when determining the pass/fail of a large number of transformers under test with the same rating or turns ratio.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic coil turns ratio testing device that eliminates the drawbacks of the prior art described above and is capable of measuring turns ratio differences with high accuracy and shortening the measurement time.

[Summary of the invention]

To achieve this objective, the present invention provides a standard transformer with the correct number of coil turns, and compares the secondary induced voltage of this standard transformer with the secondary induced voltage of the transformer under test. The present invention is characterized in that it is determined whether the number of turns of the coil is correct or not.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 2 and FIG. 3 above.

FIG. 2 shows a circuit configuration diagram of the turns ratio testing device according to the present invention, where 14 is a power switch and 15 is a slider. The primary coil 18 of the ratio test transformer 16 and the primary coil 19 of the standard transformer 17 are connected in parallel, and wired so that the same voltage is applied from the slide duck 15 to the primary coils of both transformers.

On the other hand, the secondary coil is the secondary coil 20 of the transformer under test 16.
, 21, 22, 23, 24 and the secondary coils 25, 26, 27, 28 of the standard transformer 17.

29 so that their respective polarities are reversed, and the primary coils 37, 37, .

At this time, the number of turns of each of the secondary coils 25 to 29 of the standard transformer 17 may be appropriately selected by changing taps. As a result, the voltages of the secondary coil 20 of the transformer under test 16 and the secondary coil 25 of the standard transformer 17 are connected in polar directions such that they cancel each other out. Similarly, the secondary coil 21, the primary coil 37, and the secondary coil 26
, the secondary coil 22, the primary coil 37, and the secondary coil 27,
The secondary coil 23, the primary coil 37, and the secondary coil 28, and the secondary coil 24, the primary coil 37, and the secondary coil 29 are connected. Furthermore, the secondary coil 3 of this differential voltage detection transformer 36
8, 38... are connected to amplifiers 39, 39..., respectively.

FIG. 3 shows an example of the circuit configuration of the amplifiers 39, 39, . The bias resistor 41 is a resistor for supplying a bias voltage to the base of the amplification transistor 43, and is connected between the base of the amplification transistor 43 and D
, and the + side of the C power supply. In addition, since the bias voltage is adjusted by the overhead bias resistor 42,
It is connected between the base and emitter of the amplification transistor 43.

The bias voltage is adjusted and set by the variable bias resistor 42 so that the relay 44 operates when a differential voltage is generated in the piezovoltage detection transformer 36 due to a defective number of windings. Further, the variable bias resistor 42 also performs neutralization adjustment of minute difference current due to the phase difference between the secondary side currents of the transformer under test 16 and the standard transformer 17.

The output side is the amplification tonister 43 collector and D,
A relay 44 is connected between the + side of the C electromagnetic line, and an alarm buzzer 45 and an alarm lamp 46 are connected to operate by opening and closing the contacts of the relay.

This alarm buzzer 45 and alarm lamp 46 are connected to the amplifier D,
This is an example of a circuit when the C power supply is used as is.

Note that the interlocking changeover switch 35 can be used regardless of whether the frequency of the transformer under test 16 is 50Hz or 60Hz, without replacing the standard transformer.
This is to perform measurement by switching 5.

With the above configuration, when the power switch 14 shown in FIG. A current flows into the primary coil 19 of the device 17. This secondary current causes the secondary coils 20, 21, 22, 23, 24 of the lamp pressure regulator 16 to be tested to
and the secondary coils 25, 26, 27, 28 of the standard transformer 17.
, 29 to induce an alternating current voltage.

In this case, the coils 18, 20, 21 of the transformer under test 16
, 22, 23, and 24 are correct, the number of turns of the coils 19, 25, 26, 27, 28, and 29 of the standard transformer 17 are set in the same way, so that the transformer under test 16 and the standard transformer are different. Between each secondary coil of the device 17, so-called coils 20 and 25, 21 and 26, 22 and 27, 23 and 28, 24 and 2
9, but if the ratio test transformer 1
If there is an error in the number of turns of any one of the coils, a voltage difference will occur between the two.

When a voltage difference occurs, a current due to the voltage difference flows to the primary coils 37, 37, . . . of the voltage difference detection transformer 36, and the voltage difference can be taken out to the secondary coils 38, 38, . . Since this differential voltage is very weak, it is not possible to directly operate the relay 44 or alarm buzzer 45 as it is. In order to amplify this weak voltage and operate the relay 44, alarm buzzer, and alarm lamp 46, the amplifier 39 simultaneously increases the secondary current phase difference between the transformer under test 16 and the standard transformer 17 to an amplification level using a bias voltage. It has a regulating and neutralizing effect.

The differential voltage input to amplifier 39 is applied to the base of amplifier transistor 43 by coupling capacitor 40 in FIG. The voltage applied to the base acts to increase or decrease the collector current by an amplifying effect. Now, if an AC voltage with a difference voltage is input, the collector current decreases, the relay 44 operates, the alarm buzzer 45 sounds, the alarm lamp 46 lights up, and it becomes clear which coil has the wrong number of turns.

On the other hand, if the number of turns of the primary coil 18 of the transformer under test 16 is incorrect, the secondary coils 20, 21, 22, 23,
All the voltages of 24 become high at the same time, and the balance with the standard transformer 17 is no longer maintained, and all alarm buzzers 45 and alarm lamps 46 operate.

In addition, the voltmeter 30 inserted into the secondary side of the transformer under test 16,
31, 32, 33, and 34 are connected to the secondary side of the transformer under test 16 using all-output simultaneous contact type connectors, so when the contact is incomplete, no voltage difference occurs, and it appears as if the balance between the two is unbalanced. Since the condition is the same as when the voltage was removed, it serves both the role of preventing this and the role of knowing that the correct voltage is being applied to the transformer 16 under test.

〔Effect of the invention〕

As described above, according to the present invention, an extremely small number of winding defects can be detected by an alarm, errors in the deflection of the voltmeter pointer and misreading of deflection do not affect the test, and all coils can be tested at the same time. The coil can be identified in a short time.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional electromagnetic coil turns ratio testing device, FIG. 2 is a circuit diagram of an electromagnetic coil turns ratio testing device showing an embodiment of the present invention, and FIG. 3 is a circuit diagram of a conventional electromagnetic coil turns ratio testing device. FIG. 2 is a circuit configuration diagram showing details of an amplifier. 1, 16... Transformer under test, 15... Sliduc, 17... Standard transformer, 36... Differential voltage detection transformer, 39... Amplifier, 43... Amplifying transistor, 44 ...Relay, 45...Alarm buzzer, 46...
・Warning lamp. (7317) Representative Patent Attorney Noriyuki Norichika (1 eMaka)

Claims (1)

[Claims] An electromagnetic coil characterized in that a transformer under test whose primary side is connected to an AC power source and a secondary side of a standard transformer are connected so that the induced voltages are in opposite directions, and the difference voltage is amplified and extracted. turns ratio testing equipment.