JPH04252505A - Power supply ripple measurement device - Google Patents

Abstract

PURPOSE:To realize an exclusive measuring device for ripple measurement able to measure a ripple component separately with ease of operation and small size and light weight with respect to the power supply ripple measurement device measuring the ripple component of a DC power supply unit. CONSTITUTION:The DC power supply unit rectifying a commercial power supply, applying voltage conversion to the rectified signal by an inverter and obtaining a desired DC voltage through rectification again is a measurement object. A ripple extraction section 1 separates a ripple waveform included in the measured DC voltage into a commercial frequency band component R1 and an inverter fundamental frequency band component R2, a measurement section 2 measures the input DC voltage and a ripple voltage and a frequency for each frequency band component from the said ripple extraction section and a display section 4 displays the measurement digitally.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply ripple measuring device used for maintenance and inspection of power supply units of communication devices and the like.

In communication devices and the like, commercial power is rectified by a power supply unit built into the device, converted to a predetermined voltage by an inverter, and further rectified to obtain a desired DC voltage. For stable operation of communication devices and the like, power supply units are required to have voltage stability and low ripple content, and failure of the power supply unit has a large impact.

[0003] Therefore, maintenance must be carried out on a regular basis, and in this case, it is effective to measure the ripple voltage and its frequency at the test terminal of the power supply unit in order to prevent failures. A suitable power supply ripple measuring instrument is required.

0004

2. Description of the Related Art FIG. 4 is a block diagram of a DC power supply unit to which a measuring instrument of the present invention is applied. Rectifier 6 for commercial power supply
1 for rectification, smoothing for the input filter 62, and high-speed switching (16 to 100k) for the input inverter section 63.
Hz), converts it to a high frequency, converts it to a desired voltage, rectifies it again in the rectifier 64, smoothes it through the output filter 65, and supplies it to the load. The control section 66 to which the output voltage is fed back controls the switch ON period of the transistor of the input inverter section to keep the output voltage constant.

[0005] The life of such a power supply unit is often due to deterioration of the aluminum electrolytic capacitor in the filter circuit, and the sign of this deterioration appears as a change in ripple voltage. The main ripple components are the 50Hz or 60Hz low frequency component of the commercial power supply and the switching frequency component of the inverter (referred to as the fundamental frequency, usually 16kHz to 100kHz).If you can identify the frequency and voltage of the ripple component, you can locate the fault in the power supply unit. It is extremely easy to explore.

[0006] Conventionally, there has been no measuring instrument dedicated to power supply ripple measurement. Therefore, general-purpose measuring instruments such as oscilloscopes and frequency counters were used to measure the ripple voltage and ripple frequency of the DC power supply unit for the equipment.

[0007]

[Problems to be Solved by the Invention] With conventional measuring methods, maintenance and management of the power supply unit can only be done by a person who is familiar with the use of these general-purpose measuring instruments, and such general-purpose measuring instruments are large and heavy. It is heavy and difficult to transport, and there is also the problem that it takes time to move the measuring device in cases where a large number of communication devices to be checked are distributed and arranged.

The present invention was created in view of the above problems, and an object of the present invention is to provide a power supply ripple measuring instrument that is easy to operate, small and lightweight, and capable of separately measuring ripple components.

[0009]

[Means for Solving the Problems] FIG. 1 is a diagram showing the basic configuration of a power supply ripple measuring instrument according to the present invention. As shown in Figure 1, the above problem is that the ripple of the power supply unit is measured by rectifying the commercial power supply, converting it into voltage using an inverter, and rectifying it again to obtain the desired DC voltage. Ripple extraction unit 1 that separates the ripple waveform into a commercial frequency band component R1 and an inverter fundamental frequency band component R2
and a measurement unit 2 that measures the input DC voltage and the ripple voltage and frequency for each frequency band component from the ripple extraction unit.
The power supply of the present invention is characterized in that it has a display section 4 that digitally displays these measured values, and a control section 3 that controls the operation of each section, and each of these sections is integrated. Solved by a ripple measuring device.

0010

[Operation] The ripple voltages of the commercial frequency component and the inverter fundamental frequency component can be easily and directly read based on the display of the frequency measurement value. Furthermore, since it is integrally constructed, it is easy to transport, and the workability of maintenance and management of power supply units of large quantities of communication devices and the like is improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be explained in detail below with reference to the accompanying drawings. FIG. 2 is a block diagram of an embodiment of the power ripple measuring device of the present invention, and FIG. 3 is an external view of the power ripple measuring device of the present invention.

In FIG. 2, 1 is a ripple extraction section, 2
3 is a measuring section, 3 is a control section, 4 is a display section, and 5 is a power supply section. The ripple extractor 1 extracts the DC voltage input to be measured from DC to 1.
It consists of a capacitor 11 that cuts frequencies below 0 Hz, a low-pass filter 12, and a bandpass filter 13. Low pass filter 1
2 has a cutoff at 500 Hz to separate and extract ripple components of commercial frequencies including 50/60 Hz and their harmonics, and the bandpass filter 13 has a cutoff of 16 to 100 k, which is the switching fundamental frequency of a normal inverter.
6kHz to 7kHz to separate and extract Hz and its harmonics.
It has a passband of 00kHz. The measuring section 2 includes a selector 21, a frequency measuring section 22, and two digital multimeters 23 and 24. The selector 21 selects a ripple component in either the commercial frequency band or the fundamental frequency band separated by the filter in the previous stage based on a filter select control signal from the CPU, and outputs it to the subsequent stage. The frequency measurement section 22 is composed of a frequency counter and measures the frequency of the ripple component, the first digital multimeter 23 measures the voltage amplitude of the ripple component, and the second digital multimeter 24 measures the DC voltage and calculates the frequency of the ripple component. Output as a digital value. The control unit 3 includes a CPU 31, a RAM 32, and a ROM 33. The RAM 32 temporarily stores measured values, and the ROM 33 stores programs, and the CPU 31 controls the operations of each unit based on the programs. Display section 4 is LCD
It consists of a display element and its driver, and digitally displays DC voltage, ripple component voltage, and ripple frequency under the control of CPU 31. The RS232C interface 34 transmits measurement data to an external device via a communication line. The band selection switch 35 is a switch that instructs the CPU 31 to select the commercial frequency/fundamental frequency of the ripple component to be measured. The power supply unit 5 includes a battery 44a and an external
Adapter 44 that converts 00V commercial power supply to a predetermined DC voltage
b, a switching unit 44c that switches between the adapter and the battery;
It has a power switch 45, a DC/DC converter 46, a battery check section 47, etc., and is controlled by a power supply control section 48 to supply operating voltage to each of the above sections.

All of the above-mentioned component circuits are integrally mounted in a portable housing as shown in FIG. In FIG. 3, during maintenance and inspection of the power supply unit, when the probe 10 is brought into contact with the test terminal of the power supply unit under test and the band selection switch 35 is set to the fundamental frequency (indicated in kHz) side, the inverter basic frequency of the power supply unit under test is set. The voltage and frequency of the ripple component of the frequency are displayed digitally at the same time as the DC voltage, and when the band selection switch 35 is set to the low frequency (Hz display) side, the voltage and frequency of the ripple component of the commercial frequency are displayed digitally along with the DC voltage. .

Therefore, the ripple component of the power supply unit can be easily measured by separating it into the commercial frequency band and the inverter fundamental frequency band. Furthermore, by connecting a communication line to the connector of the RS232C interface unit 42, measurement data can be sent to an external measurement device. The battery check section lights up when the internal battery is depleted.

[0015]

As explained above, according to the present invention, ripple waveforms can be directly read as digital values for each component of both the commercial frequency band and the inverter fundamental frequency band, making it easy to measure ripples in power supply units and improving communication equipment, etc. Improves the workability of maintenance management.

[Brief explanation of the drawing]

[Figure 1] Principle configuration diagram of the power supply ripple measuring device of the present invention

[Figure 2] Block diagram of the power supply ripple measuring device of the present invention

[Figure 3] External view of the power supply ripple measuring device of the present invention

[Figure 4] Block diagram of a DC power supply unit targeted by the measuring instrument of the present invention

[Explanation of symbols]

1-Ripple extraction section, 12-Low pass filter, 13-Band filter, 2-Measurement section, 21-Frequency counter, 22,
23 - Digital multimeter, 3 - Control section, 35 -
Band selection switch, 4-display section, 5-power supply section,

Claims (1)

[Claims] Claim 1: Measures the ripple of a power supply unit that rectifies a commercial power supply, converts the voltage using an inverter, and rectifies it again to obtain a desired DC voltage, and converts the ripple waveform contained in the DC voltage to the commercial frequency. Band component (R1)
and a ripple extraction section (1) that separates the input DC voltage into the basic frequency band component (R2) of the inverter, and a measurement that measures the ripple voltage and frequency for each frequency band component from the input DC voltage and the ripple extraction section (1). (2), a display section (4) that digitally displays these measured values, and a control section (3) that controls the operation of each section, and each of these sections is configured in one piece. A power ripple measuring instrument featuring: