Charging circuit

Abstract

This system uses a simple configuration to determine AC waveforms. [Solution] The charging circuit 2 comprises a plurality of power lines through which at least alternating current flows as input current, and a first sensor S1 and a second sensor S2 that measure the voltage of the input current as digital sensors. The plurality of power lines include an ungrounded power line 21 through which the input current flows to the first sensor S1, a grounded power line 22 through which the current that has passed through the first sensor S1 flows to the ground, and a branched power line 23 that branches off from the grounded power line 22 and supplies current to the second sensor S2. The system includes a merging power line 24 that carries the current that has passed through the second sensor S2 to the ungrounded power line 21.

Description

Technical Field

[0001] This disclosure relates to a charging circuit.

Background Art

[0002] As described in Patent Document 1 below, it is known to measure an alternating current with a voltage sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, when the power quality of an alternating current waveform is poor, such as a pseudo-sine wave, when using a digital sensor to determine the presence or absence of voltage, it was not possible to correctly determine the alternating current waveform. On the other hand, when using an analog sensor, there is a problem that the circuit becomes expensive, and it was not possible to determine the alternating current waveform with a simple configuration.

[0005] An object of this disclosure is to determine an alternating current waveform with a simple configuration.

Means for Solving the Problems

[0006] This disclosure is a charging circuit, comprising: a plurality of power lines through which at least an alternating current flows as an input current; a first sensor and a second sensor that measure the voltage of the input current as a digital sensor. The plurality of power lines include: a non-grounded side power line through which the input current flows to the first sensor; a grounded side power line through which the current passing through the first sensor flows to the ground side; a branched power line branched from the grounded side power line and flowing a current to the second sensor; and a combined power line through which the current passing through the second sensor flows to the non-grounded side power line.

Effects of the Invention

[0007] According to this disclosure, AC waveforms can be determined with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing the charging circuit according to this embodiment. [Figure 2] Figure 2 shows an example of the waveform of the grid voltage input to the charging circuit shown in Figure 1. [Figure 3] Figure 3 shows an example of sensor output when the system voltage shown in Figure 2 is input to the charging circuit shown in Figure 1. [Figure 4] Figure 4 is a diagram showing a charging circuit according to a comparative example. [Figure 5] Figure 5 shows an example of the waveform of the system voltage input to the comparative example and an example of the sensor output. [Modes for carrying out the invention]

[0009] This embodiment will now be described with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0010] As shown in Figure 1, the charging circuit 2 according to this embodiment includes an ungrounded power line 21, a grounded power line 22, a branch power line 23, a merging power line 24, a first sensor S1, and a second sensor S2.

[0011] The first sensor S1 and the second sensor S2 are digital sensors capable of determining the presence or absence of voltage. The first sensor S1 is connected to the ungrounded power line 21. The ungrounded power line 21 is configured so that the input current flows to the first sensor S1. More specifically, the input current is configured to flow along the direction from the collector side to the emitter side of the transistor in the first sensor S1 and be input to the base side. A diode D1 is provided upstream of the first sensor S1 on the ungrounded power line 21.

[0012] The first sensor S1 is also connected to the grounded power line 22. The grounded power line 22 is configured so that the current that passes through the first sensor S1 flows to the ground.

[0013] A branch power line 23 is provided to branch off from the grounded power line 22 and supply current to the second sensor S2. More specifically, the input current is configured to flow along the direction from the emitter side to the collector side of the transistor in the second sensor S2 and be input to the base side. A diode D2 is provided on the upstream side of the second sensor S2 in the branch power line 23. The merging power line 24 is provided so that the current that has passed through the second sensor S2 flows to the ungrounded power line 21.

[0014] By configuring the charging circuit 2 as described above, the first sensor S1 functions as a digital voltage sensor capable of determining the presence or absence of voltage only on the positive side, and the second sensor S2 functions as a digital voltage sensor capable of determining the presence or absence of voltage only on the negative side.

[0015] When a pseudo-sine wave system voltage, as illustrated in Figure 2, is input, the sensor output will be as illustrated in Figure 3. Figure 3(A) illustrates the sensor output of the first sensor S1. Figure 3(B) illustrates the sensor output of the second sensor S2.

[0016] To clarify the technical features of the charging circuit 2 according to this embodiment, a comparative example charging circuit 2A will be described with reference to Figure 4. As shown in Figure 4, the charging circuit 2A comprises an ungrounded power line 21A, a grounded power line 22A, a bridge circuit BS, and a digital sensor SA. The bridge circuit BS is a rectifier circuit composed of four diodes D1, D2, D3, and D4.

[0017] In the digital sensor SA, a DC positive voltage is obtained at the sensor output only while the input voltage exceeds the threshold value, and the sensor output becomes 0 when a voltage below the threshold value is input. Also, regardless of the positive or negative of the input AC waveform, the sensor output becomes a positive voltage.

[0018] When a normal sine wave as illustrated in FIG. 5(A) is input, since a timing occurs where the output becomes 0 without exceeding the threshold value between the output positive voltages according to the determination results on the positive side and the negative side, a sensor output as illustrated in FIG. 5(B) is obtained, and frequency components can be detected and determined as AC.

[0019] On the other hand, when the potential difference between the positive and negative sides changes rapidly, such as in a pseudo-sine wave or a pulse wave as described while referring to FIG. 2, the outputs according to the determination results of the positive-side voltage and the negative-side voltage wrap around, so that a timing where the output becomes 0 cannot be obtained, frequency components cannot be detected, and it is misjudged as DC, resulting in a sensor output as illustrated in FIG. 5(C).

[0020] The charging circuit 2 according to the present embodiment described above provides the first sensor S1 and the second sensor S2 as two digital sensors, with the first sensor S1 taking on the positive-side output and the second sensor S2 taking on the negative-side output, thereby avoiding misjudgments as in the comparative example and enabling detection of frequency components.

[0021] The present embodiment has been described above while referring to specific examples. However, the present disclosure is not limited to these specific examples. Those obtained by appropriately making design changes by those skilled in the art to these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in the above-described specific examples and its arrangement, conditions, shape, etc. are not limited to those illustrated and can be appropriately changed. Each element included in the above-described specific examples can be appropriately combined as long as no technical contradiction occurs.

[0022] [Appendix] [Appendix 1] At least a plurality of power lines through which an alternating current flows as an input current, It comprises a first sensor S1 and a second sensor S2 that measure the voltage of the input current as digital sensors, Multiple power lines, The ungrounded power line 21 through which the input current flows to the first sensor S1, The current that has passed through the first sensor S1 flows to the ground side via the ground power line 22, A branch power line 23 that branches off from the ground power line 22 and supplies current to the second sensor S2, A charging circuit 2 includes a merging power line 24 that carries the current that has passed through the second sensor S2 to the ungrounded power line 21.

[0023] According to Appendix 1, the first sensor S1 functions as a digital voltage sensor capable of determining the presence or absence of voltage only on the positive side, and the second sensor S2 functions as a digital voltage sensor capable of determining the presence or absence of voltage only on the negative side. Even if the input current is an AC waveform with poor power supply quality, such as a pseudo-sine wave, the determination can be made with an inexpensive and simple configuration. In addition to AC current, DC current may also flow as the input current, and the first sensor S1 and the second sensor S2 may determine whether or not it is a DC current. [Explanation of symbols]

[0024] 2: Charging circuit 21: Ungrounded power line 22: Grounded power line 23: Branch power lines 24: Combined power lines S1: First sensor S2: Second sensor D1, D2: Diodes

Claims

[Claim 1] At least multiple power lines through which alternating current flows as input current, It comprises a first sensor and a second sensor that measure the voltage of the input current as digital sensors, The aforementioned multiple power lines are, The input current flows to the first sensor via the ungrounded power line, The current that has passed through the first sensor flows to the ground side in the ground power line, A branch power line that branches off from the aforementioned ground power line and supplies current to the second sensor, A charging circuit comprising a converging power line that carries the current that has passed through the second sensor to the ungrounded power line.

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