JPH01260369A - Life forcasting circuit for power supply apparatus - Google Patents

Abstract

PURPOSE:To achieve an accurate life forecasting allowed for an ambient temperature without adding a separate circuit, by measuring a temperature of an electrolytic capacitor directly with a temperature sensor to forecast the life of a power source device based on the temperature and a consumption index. CONSTITUTION:A temperature of an electrolytic capacitor forming a power source circuit 6 in a power source device 7 is measured with a temperature sensor 1. Based on a detection value thus obtained, a voltage value of a consumption index is computed with a computation circuit 2 from a specified relationship between the temperature and a useful life time and a frequency pulse proportional to the voltage value is outputted with a V/F converter 3. Moreover, the frequency pulse is integrated sequentially with an integration counter 4 to be shown on a display device 5. This enables accurate forecasting of the life of an electrolytic capacitor with due regard to an ambient temperature without requiring a user to add a circuit outside.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a power supply device using an electrolytic capacitor, which is a life-span component, and is particularly applicable to fields such as industrial equipment where failure is not allowed, and is used to predict the lifespan of a power supply. The present invention relates to a lifespan prediction circuit for a power supply device that can be used as a power supply device.

[Conventional technology]

A conventional life prediction circuit for this type of power supply device is shown as a block diagram in FIG.

In the same figure, a conventional power supply life prediction circuit is connected to a power supply (7) formed of an electrolytic capacitor and to the outside of the power supply (7), and calculates the cumulative energization time to the power supply (7). An hour meter (8) to display, a power supply (10) that supplies charge to the power supply device (7), and a power supply device (7).
The configuration includes a switch (9) that is connected between the power supply device (7) and controls the supply of charge to the power supply device (7) on and off.

Next, the operation of the conventional life prediction circuit based on the above configuration will be explained. First, when the switch (9) is turned on, the power supply (7) becomes operational, and the hour meter (8) also operates. will be displayed. Therefore, when the previously predicted life time has been reached, the power supply device (7) is replaced. [Problem to be solved by the invention] Since the life prediction circuit of the conventional power supply device as described above is configured as described above, it is not built into the power supply device. It is necessary to connect it to a separate power supply, and this lifespan circuit does not take into account fluctuations in the ambient temperature of the electrolytic capacitor that forms the power supply, resulting in inaccurate predictions. Generally, the life of an electrolytic capacitor is said to be halved if the ambient temperature rises by 10°C, and the influence of ambient temperature is significant.

This invention was made in order to solve this problem, and the purpose is to obtain a lifespan prediction circuit for a power supply device that can accurately predict lifespan in consideration of temperature without requiring the user to add a separate circuit to the power supply device. shall be.

[Means to solve the problem]

A lifespan prediction circuit for a power supply device according to the present invention measures the temperature of an electrolytic capacitor inside the power supply device using a temperature sensor, and predicts and displays the lifespan of the power supply device based on this temperature.

[Effect]

In the life prediction circuit according to the present invention, since the temperature sensor directly measures the temperature of the electrolytic capacitor, which is a lifespan component, it is possible to accurately predict the lifespan by taking into account fluctuations in ambient temperature, which greatly affects the lifespan of the electrolytic capacitor. can.

(Example) Hereinafter, a life prediction circuit for a power supply device according to an example of the present invention will be explained based on FIG. FIG. 1 shows a block diagram of the life prediction circuit of this embodiment. In the same figure, the life prediction circuit of the power supply device according to this embodiment is
A temperature sensor (1) is attached to the electrolytic capacitor forming the power supply circuit (6) in (7) and measures the temperature of the electrolytic capacitor, and the temperature and service life are determined based on the detected value of the temperature sensor (1). an arithmetic circuit (2) that calculates a voltage value of a consumption index from a predetermined relationship;
A V/F converter (3) that outputs a frequency pulse proportional to the voltage value of the V/F converter (3), an integration counter (4) that integrates the frequency path of the V/F converter (3), and an integration counter (4) that integrates the frequency path of the V/F converter (3). This configuration includes a display device (5) that displays values.

The power supply device (7) according to this embodiment configured as described above
), the temperature sensor (1) measures the temperature of the power supply circuit (6) formed by the electrolytic capacitor in the power supply device, and when the temperature rises by 10°C from the reference temperature by the following calculation circuit (2), the temperature is 20°C. It outputs twice the voltage, and half the voltage when the temperature drops by 10 degrees Celsius.

In other words, the power supply circuit formed by this electrolytic capacitor (
The life curve 6) is generally defined by the "10° C. double rule" and is expressed by equation (a).

1, , - L, X 2 (TI-72/101
,,, (a) LI: Effective life at maximum operating temperature L2: Effective life at operating temperature T1: Maximum operating temperature T2: Operating temperature This is graphed as shown in Figure 2.

Then, a V/F converter (3) outputs a pulse with a frequency proportional to this voltage, which is integrated by an integration counter (4). This integration counter (4) maintains an integrated value even when the source device (7) is not in operation, and the integrated value is always displayed on the display (5). The lifespan of the electrolytic capacitor in the power supply circuit (6) at the reference temperature is specified by the capacitor manufacturer, so set the integration counter (4) to count up according to the life time at this reference temperature. put. With this arrangement, if the temperature rises by 10°C from the reference temperature, the count will increase in half the time, and if the temperature falls by 10°C, it will take twice as long to count up.

For example, if the period is T at room temperature (25°C), then at 35°C it is T/2. At 15°C it is 2T.

Therefore, it can be inferred that the higher the temperature, the shorter the time until count-up and the shorter the life of the power supply (7). The opposite is true at low temperatures.

When the power supply device (7) reaches a count value that is considered to be nearing the end of its life, the integration counter (4) returns a count-up signal to the CPU (not shown).

In response to this, this CPU outputs an output from the display (5) based on the alarm signal to the outside.

In this way, since the temperature of the electrolytic capacitor in the power supply circuit (6) is constantly measured and the count input is changed, it is possible to accurately predict the lifespan in response to temperature fluctuations.

In the above embodiment, the temperature in the electrolytic capacitor of the power supply circuit (6) is measured by the temperature sensor (1), and the integration counter (
We have explained the method of changing the cycle in 4), but if there are other factors or parts used to estimate the lifespan of the power supply, you can configure the circuit by considering their regularity and measurement method. The lifespan may be estimated using not only temperature but also other parameters such as humidity and vibration.

〔Effect of the invention〕

As explained above, this invention is configured to measure the temperature of the electrolytic capacitor that forms the power supply device and predict the life based on this, thereby predicting the life of the power circuit of the electrolytic capacitor based on the temperature and wear index. This allows the user to make accurate life predictions that take temperature into account without adding an external circuit. In addition, there is no need to troubleshoot after a failure occurs or to replace the device even though there is still plenty of time left in its life, making it possible to operate the system more efficiently.

4. Brief explanation of the drawings Fig. 1 is a configuration diagram of a lifespan prediction circuit of a power supply device according to an embodiment of the present invention, Fig. 2 is a front diagram showing the lifespan of an electrolytic capacitor in a power supply circuit, and Fig. 3 is a diagram showing temperature FIG. 4 is a diagram of a pulse waveform showing the cycle of an integration counter that varies depending on the period of the integration counter. FIG.

In the figure, (1) is a temperature sensor, (2) is an arithmetic circuit, and (3) is a V
/F converter, (4) is integration counter, (5) is display, (6) is power supply circuit, (7) is power supply, (8) is hour meter,
(9) is a switch.

Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] In a power supply device that stores electric charge in an electrolytic capacitor and supplies power by discharging the electric charge, a temperature measuring means for measuring the temperature of the electrolytic capacitor, and a measured value of the temperature measuring means and a preset consumption index are provided. and an integrating means for holding and successively integrating the calculation results of the calculating means, and for predicting the life of the power supply based on the integrated results of the integrating means. Features a lifespan prediction circuit for power supply equipment.