JP2634626B2 - Charging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a battery at a constant current and displaying a state of charge.

[Conventional technology]

A charging device for charging a battery is built in an emergency light, a guide light, or the like, and is configured to charge, for example, a Ni-Cd battery for turning on an emergency lighting lamp when a commercial power supply fails. Such a charging device is configured to supply a charging current to a battery by stepping down and rectifying the voltage of a commercial power supply,
A constant charging current can always be supplied regardless of fluctuations in the voltage of the commercial power supply.

If the battery to be charged is a Ni-Cd battery, the self-discharge of the battery is relatively large, so the self-discharge must be compensated in order to keep the battery fully charged and use the battery capacity effectively. It is necessary to always supply a charging current so as to perform charging (trickle charging method).

However, if the charging current to the battery becomes unnecessarily large, the battery may be overcharged and the life of the battery may be shortened.

Therefore, the charging current to the battery needs to be set within an optimum range in which the self-discharge of the battery can be compensated without any excess or shortage. For example, in the case of an emergency light or a guide light, it is optimal that the charging current is in the range of (1/30) C to (1/20) C (where C is the nominal capacity of the battery). It is known.

In the case of an emergency light or a guide light, it is recommended to display the state of charge so that the state of charge can always be confirmed.

As shown in FIG. 4, the conventional charging device that performs the above-described constant current charging and displays the charging is provided with a charging power source 1 that supplies a charging current to a battery B, and the charging power source I It is inserted in series through the charge current intermittent switching elements Q ₁ and diode D ₂ of the protective comprising transistors in the feed path of the charging current to the B.

Further, provided the current detection circuit II for generating an average charging current corresponding voltages V ₁ detects the charging current, the average charging current connection corresponding voltages V ₁ and the resistor R ₅ and a Zener diode ZD ₁ output from the current detection circuit II The charging current setting voltage V ₂ obtained at the point
The average charging current corresponding voltage V ₁ is the charging current setting voltage comparing bets
Mean By interrupting the charging current intermittent switching elements Q ₁ when the average charging current corresponding voltages V ₁ together to conduct the charging current intermittent switching element Q ₁ is higher than the charging current setting voltage V ₂ when lower than V ₂ A charge control circuit for controlling the charge current to a constant value capable of compensating the self-discharge of the battery B without excess or deficiency.
III is provided.

Also, a charging display element LED ₁ composed of a light emitting diode,
A display element driving power supply IV for driving the charging display element LED ₁
The power supply IV for driving the display element and the charging display element LE
The average charging current corresponding voltage consists transistor between the D ₁
With increasing V ₁ is interposed a resistor R ₁₀ of the display control switching element Q ₃ and current limiting conductive.

The charging device, the charging current is supplied to the battery B from the charging power source I through charging current intermittent switching elements Q ₁ and diode D _2. At this time, current detection circuit II detects the charging current, generating the average charging current corresponding voltages V ₁ corresponding to the average value of the charging current.

Charge control circuit III, the resistance R ₅ and a Zener diode compares the average charging current corresponding voltage V ₁ output from the charging current setting voltage V ₂ and current detecting circuit II obtained at the connection point of ZD _1, the result of the comparison It will determine the charging current intermittent switching element Q ₁ in accordance with the. Specifically, when the average charging current corresponding voltages V ₁ is lower than the charging current setting voltage V ₂ is to conduct the charging current intermittent switching elements Q _1, average charging current corresponding voltages V ₁ is higher than the charging current setting voltage V ₂ when high to cut off the charging current intermittent switching elements Q _1, thereby controlling to a constant value the average charging current supplied from the charging power source I to the battery B is to compensate just proportion self-discharge of the battery B.

The average charging when a current corresponding voltages V ₁ is zero or somewhat increased, the average charging current corresponding voltages V ₁ and resistor R _8, divided voltage display control switch element R ₉ output from the current detection circuit II made it exceeds the base-emitter saturation voltage of Q is _three transistors. As a result, the charging display element LED ₁ conducts the display control switch element Q ₃ is turned on, the battery B
Indicates that is connected and charging is being performed.

[Problems to be solved by the invention]

The conventional charging device described above uses the average charging current corresponding voltage V ₁
Since There were only configured to illuminate the charge display device LED ₁ by conducting the display control switch element Q ₃ when merely somewhat increased from zero, i.e. regardless of the magnitude of the charging current, the charging current is merely flows Just charge display element
Since the LED ₁ was turned on, it was not preferable because the light was turned on in the same manner as when the battery was normally charged even when the charging current became smaller than the value required for compensating the self-discharge of the battery B.

To solve such a problem, for example, a resistor
By inserting the R ₈ in series with the zener diode, it is conceivable that the average charging current corresponding voltages V ₁ does not exceed a certain value and a display control switch element Q ₃ is configured to not conduct.
However, it is necessary to select a Zener diode having a different Zener voltage each time the capacity of the battery B to be charged is changed, and it is difficult to cope with the change in the capacity of the battery B, and the versatility is lacking. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to display a charge only when the charge current of the battery is sufficient to compensate for the self-discharge of the battery, and to easily change the capacity of the battery. It is to provide a charging device capable of coping with the above.

[Means for solving the problem]

The charging device of the present invention includes a charging power supply for supplying a charging current to a battery, and a charging current intermittent switch element is inserted in series in a supply path of the charging current from the charging power supply to the battery.

Also, a current detection circuit for detecting a charging current and generating an average charging current corresponding voltage is provided, and the average charging current corresponding voltage output from the current detection circuit is compared with the charging current setting voltage, and the average charging current corresponding voltage is determined as the charging current. When the voltage is lower than the set voltage, the charge current intermittent switch element is turned on, and when the average charge current corresponding voltage is higher than the charge current set voltage, the charge current intermittent switch element is turned off, thereby reducing the self-discharge of the battery. A charge control circuit for controlling to a constant value for compensation is provided.

Further, a charge display element and a display element drive power supply for driving the charge display element are provided, and a display control switch element is interposed between the display element drive power supply and the charge display element.

Also, while maintaining a predetermined ratio of 1 or less with respect to the charging current setting voltage, the charging display setting voltage, which changes with the change of the charging current setting voltage, is compared with the average charging current corresponding voltage. A display control circuit is provided for turning on the display control switch element when the charge display set voltage is exceeded. The charging display setting voltage is obtained by, for example, dividing the charging current setting voltage.

[Action]

According to the configuration of the present invention, the charging current is supplied to the battery from the charging power supply through the charging current switching switch element. At this time, the current detection circuit detects the charging current and generates an average charging current corresponding voltage corresponding to the average value of the charging current.

The charging control circuit compares the charging current setting voltage with the average charging current corresponding voltage output from the current detection circuit, and switches the charging current switching switch on and off according to the comparison result. In this case, when the average charging current corresponding voltage is lower than the charging current setting voltage, the charging current interrupting switch element is turned on, and when the average charging current corresponding voltage is higher than the charging current setting voltage, the charging current interrupting switch element is shut off. .
As a result, the average charging current supplied from the charging power supply to the battery has a constant value that compensates for the self-discharge of the battery.

In addition, when the average charging current corresponding voltage output from the current detection circuit rises from zero and the average charging current corresponding voltage exceeds the charging display set voltage, the display control switch element is turned on and the charging display element is turned on. Indicates that the battery is connected and that sufficient charge current is flowing through the battery to compensate for self-discharge. On the other hand, if the battery is not connected, and even if the battery is connected and the charging current is supplied to the battery but its value is not enough to compensate for self-discharge, the voltage corresponding to the average charging current is charged. The display setting voltage is not exceeded, so the display control switch element does not conduct,
Charging indicator does not light.

When the capacity of the battery to be charged is changed and the charging current setting voltage is changed according to the capacity of the battery, the charging display setting voltage is automatically changed in conjunction with the change of the charging current setting voltage. Will be.

〔Example〕

One embodiment of the present invention will be described with reference to FIG. 1 and FIG. As shown in FIG. 1, this charging apparatus includes a charging power supply I for supplying a charging current to a battery B, and a charging current comprising a transistor in a supply path of the charging current from the charging power supply I to the battery B. It is inserted in series through the intermittent switching elements Q ₁ and diode D ₂ of the protective.

Further, provided the current detection circuit II for generating an average charging current corresponding voltages V ₁ detects the charging current, the average charging current connection corresponding voltages V ₁ and the resistor R ₅ and a Zener diode ZD ₁ output from the current detection circuit II The charging current setting voltage V ₂ obtained at the point
The average charging current corresponding voltage V ₁ is the charging current setting voltage comparing bets
Mean By interrupting the charging current intermittent switching elements Q ₁ when the average charging current corresponding voltages V ₁ together to conduct the charging current intermittent switching element Q ₁ is higher than the charging current setting voltage V ₂ when lower than V ₂ A charge control circuit for controlling the charge current to a constant value capable of compensating the self-discharge of the battery B without excess or deficiency.
III is provided.

Also, a charging display element LED ₁ composed of a light emitting diode,
A display element driving power supply IV for driving the charging display element LED ₁
The power supply IV for driving the display element and the charging display element LE
D ₁ is interposed a resistor R ₁₀ of the display control switching element Q ₃ Oyohi limit diverted comprising transistors between.

Further, a charging display set voltage V ₃ that varies with the change of the charging current setting voltage V ₂ in a state in which respect the charging current setting voltage V ₂ was kept 1 following a predetermined ratio between the average charging current corresponding voltages V ₁ comparing the average charging current corresponding voltage V ₁ is charged display setting voltage V ₃
The is provided a display control circuit VII for conducting a display control switch element Q ₃ when it exceeds.

The charging device, the charging current is supplied to the battery B from the charging power source I through charging current intermittent switching elements Q ₁ and diode D _2. At this time, current detection circuit II detects the charging current, generating the average charging current corresponding voltages V ₁ corresponding to the average value of the charging current.

Charge control circuit III, the resistance R ₅ and a Zener diode compares the average charging current corresponding voltage V ₁ output from the charging current setting voltage V ₂ and current detecting circuit II obtained at the connection point of ZD _1, the result of the comparison It will intermittently charging current intermittent switching element Q ₁ in accordance with the. Specifically, when the average charging current corresponding voltages V ₁ is lower than the charging current setting voltage V ₂ is to conduct the charging current intermittent switching elements Q _1, average charging current corresponding voltages V ₁ is higher than the charging current setting voltage V ₂ high time to cut off the charging current intermittent switching element Q _1. As a result, the average charging current supplied from the charging power source I to the battery B is
Is a constant value for compensating the self-discharge of the battery without excess or shortage.

Further, the average charging current corresponding voltage V ₁ output from the current detection circuit II rises from zero, and this average charging current corresponding voltage V ₁
When but it exceeds charging display setting voltage V _3, and conducts display control switch element Q ₃ lights charging display element LED _1, sufficient charging to compensate the self-discharge is connected to the battery B in the battery B Indicates that current is flowing. On the other hand, when the battery B is not connected, and even when the battery B is connected and the charging current is supplied to the battery B, its value is not enough to compensate for the self-discharge, the average charging current It does not exceed the V ₃ the voltage V ₁ charging display setting voltage. Therefore, the display control switch element Q ₃ does not conduct, and the charge display element LED ₁
Does not light.

Further, by changing the capacity of the battery B to be charged, when changing the charge current setting voltage V ₂ in accordance with the capacity of the battery B, charging display setting voltage V ₃ is linked to changes in the charging current setting voltage V ₂ Will be changed automatically.

 Hereinafter, this charging device will be described in more detail.

The charging power supply I converts the voltage of the commercial power supply E into a step-down transformer T _1.
In stepped down by further full-wave rectified by the full-wave rectifier DB _1, so as to obtain the DC power. Then, the charging power supply 1 supplies the charging current to the battery B through the charging current intermittent switching elements Q ₁ and diode D _2.

Current detecting circuit II includes a resistance R ₁ of the charging current detection interposed in series in the supply path of the charging current to the battery B, the resistor
An integrating circuit V that averages the voltages of R _1, comprising a non-inverting amplifier circuit VI for noninverting amplifier output voltage of the integration circuit V. Integration circuit V is composed of a resistor R ₂ and capacitor C _2, a non-inverting amplifier circuit VI is composed of an operational amplifier OP _1, resistors R _3, R _4. In the current detection circuit II, together with integrating the voltage across the resistor R ₁ which is proportional to the charging current by the integrating circuit V,
By amplifying a non-inverting amplifier circuit VI, average charging current corresponding voltages V ₁ from the output terminal of the noninverting amplifier circuit VI occurs.

The charge control circuit III includes an operational amplifier OP ₂ , resistors R ₆ and R _7, and a transistor Q ₂ . The display element voltage at the midpoint of the series circuit of the connected resistor R ₅ and a Zener diode ZD ₁ to the output terminal of the drive power supply IV, i.e. the zener diode ZD ₁ Zener voltage the charging current setting voltage V
Enter as ₂ . Furthermore, by comparing the average charging current corresponding voltage V ₁ of the above and the charging current setting voltage V _2, when the average charging current corresponding voltages V ₁ is lower than the charging current setting voltage V _2, the high output of the operational amplifier OP ₂ in the level to conduct the transistors Q _2, thereby to conduct the charging current intermittent switching elements Q _1, flow the charging current to the battery B. On the other hand, when the average charging current corresponding voltage V ₁ is higher than the charging current setting voltage V _2, and the output of the operational amplifier OP ₂ in the low-level to block the transistor Q _2, thereby the charging current intermittent switching elements Q ₁ Then, the supply of the charging current to the battery B is cut off.

Or more of the charging current intermittent switch element Q ₁ of intermittent results,
The average charging current supplied to the battery B is controlled to a constant value, that is, a value that compensates for the self-discharge of the battery B without excess or deficiency.

The display control circuit VII is composed of an operational amplifier OP ₃ and a resistor R ₁₃ , and a charge display set voltage V ₃ obtained by dividing a charge current set voltage V ₂ by resistors R ₁₁ and R ₁₂ and an average charge current corresponding voltage V 3. ₁ and the average charge current corresponding voltage V ₁ is the charge display set voltage
The output of the operational amplifier OP ₃ is to conduct a display control switch element Q ₃ becomes high level when it exceeds V _3. As a result, indicating that the charging current to the battery B is charged display device LED ₁ lit becomes a value capable of sufficiently compensating for the self-discharge of the battery B.

If the charging current cannot be sufficiently obtained due to some abnormality (for example, a voltage drop of the commercial power supply E),
The average charging current corresponding voltages V ₁ does not exceed the charging display setting voltage V _3. Accordingly, the operation output of the amplifier OP ₃ is turns off the charging display element LED ₁ by blocking the display control switch element Q ₃ becomes low level.

Display element driving power source IV is composed of a series circuit of a capacitor C ₁ of the diode D ₁ and smoothed.

Figure 2 is a characteristic diagram showing the relationship between the power supply voltage and the charging current of the commercial power supply E in the charging device of FIG. 1, a solid line A ₁ is set value is a characteristic in the case of I _1, a solid line A ₂ is set value is characteristic of I _2.

As is apparent from this figure, charging device, when the power supply voltage is higher than the predetermined value V _x, the average charging current to the battery B a charging current intermittence of intermittent switching element Q ₁ by the charging control circuit III set value It is held in the I ₁ or I _2. However, when the power supply voltage falls below V _X, it is continuously conductive and thereby the charging current intermittent switching element Q _1, the charging current setting value I ₁
Or not reach I _2, the charging current also decreases with decreasing power supply voltage.

Further, as it is clear from Figure 2, when the set value of the average charging current is I _1, the display setting value I ₁ 'next to illuminate the charge display element LED _1, the average charging current display setting value
When I ₁ ′ is exceeded, the charge display element LED ₁ is turned on. Also, when the set value of the average charging current is I _2, the charging display element LE
Display settings turning on the D ₁ is I ₂ ', and the average charging current display setting value I _2' charging display element LED ₁ exceeds lights.

Charging apparatus of this embodiment, interposed the display control switch element Q ₃ between the charging display device LED ₁ and the display element driving power source IV, a charging display setting voltage V ₃ and the average charging current corresponding voltages V ₁ comparing the average charging current corresponding voltage V ₁ is charged display setting voltage V ₃
Since the provided display control circuit VII for conducting a display control switch element Q ₃ when it exceeds, only to perform charging display when the charging current of a value sufficient to compensate for self-discharge the battery B flows be able to.

Moreover, since it is configured to vary the charge display setting voltage V ₃ in accordance with the change of the charging current setting voltage V ₂ while maintaining a predetermined ratio of 1 or less with respect to the charging current setting voltage V _2, the battery B in conjunction with the average of the charging current setting voltage V ₂ will be charging display setting voltage V ₃ is changed, which is determined in accordance with the capacity, by simply changing the charge current setting voltage V ₂ for capacitive changes of the battery B Often, it is possible to easily cope with a change in the capacity of the battery B, and the versatility is high. In particular, only be modified, for example the resistor R ₁ when the module by using a small device or aggregate element circuit, also corresponding to the battery B of any capacity,
Especially high versatility.

A second embodiment of the present invention will be described with reference to FIG. This emergency light lighting device is configured to include the charging device of the present invention.

That is, this emergency light lighting device is provided with a charging power supply I for supplying a charging current to a battery B, and a charging current intermittent switch element comprising a transistor in a supply path of the charging current from the charging power supply I to the battery B. the Q ₁₁ and its protective diode D ₁₃ is inserted in series through.

Also, 'provided, the current detecting circuit II' current detecting circuit II for generating an average charging current corresponding voltage V ₁₁ detects the charging current connections average charging current corresponding voltage V ₁₁ and the resistor R _29, R ₃₀ output from the average charging current corresponding voltage V with the average charging current corresponding voltage V ₁₁ is compared with the charging current setting voltage V ₁₂ obtained point is to conduct the charging current intermittent switching elements Q ₁₁ when lower than the charging current setting voltage V _{12 11} the charging control circuit III for controlling the constant value of the self-discharge can without excess or deficiency compensation cell B the average charging current by interrupting the charging current intermittent switching elements Q ₁₁ when higher than the charging current setting voltage V ₁₂ '
Is provided.

Also, a charging display element LED ₂ composed of a light emitting diode,
The display element driving power supply I for driving the charging display element LED ₂
'Provided and, the display element driving power source IV' V is interposed a switching element for display control of transistors Q ₁₃ and the resistor R ₃₅ of the current limiting between the charging display element LED _2.

Also, charging and charging display setting voltage V ₁₃ that varies with the change of the charging current setting voltage V ₁₂ in a state of relative charge current setting voltage V ₁₂ was kept less than one predetermined ratio current-dependent voltage V ₁₁
And the charging current corresponding voltage V ₁₁ is the charging display regulation voltage V ₁₃
It is provided with a display control circuit VII 'for conducting a display control switch element Q ₁₃ when exceeded.

The emergency light lighting device, charging current is supplied to the battery B through the charging current intermittent switching elements Q ₁₁ and diode D ₁₃ from the charging power source I. At this time, the current detection circuit I
I 'detects the charging current, generating the average charging current corresponding voltage V ₁₁ corresponding to the average value of the charging current.

Charge control circuit III 'includes a charging current setting voltage V ₁₂ current detecting circuit II' compares the average charging current corresponding voltage V ₁₁ outputted from the charging current intermittent switching elements Q ₁₁ according to the comparison result It will be intermittent. Specifically, when the average charging current corresponding voltage V ₁₁ is lower than the charging current setting voltage V ₁₂ is allowed to conduct the charging current intermittent switching elements Q _11, average charging current corresponding voltage V ₁₁ is higher than the charging current setting voltage V ₁₂ high time to cut off the charging current intermittent switching element Q _11. As a result, the average charging current supplied from the charging power supply I to the battery B becomes a constant value that compensates for the self-discharge of the battery B without excess or deficiency.

Also, increased average charging current corresponding voltage V ₁₁ outputted from the current detection circuit II 'is from zero, the average charge current corresponding voltage V ₁₁ exceeds the charging display setting voltage V _13, a display control switch element Q ₁₃ Is turned on, the charge indicator LED ₂ lights up,
It indicates that the battery B is connected and a sufficient charge current is flowing through the battery B to compensate for self-discharge. On the other hand, when the battery B is not connected, and even when the battery B is connected and the charging current is supplied to the battery B, its value is not enough to compensate for the self-discharge, the average charging current the voltage V ₁₁ does not exceed the charging display set voltage V _13. Thus not conduct display control switch element Q _13, charging the display element LED ₂ does not light.

Also, when you change the capacity of the battery B to be charged was changed charge current setting voltage V ₁₂ in accordance with the capacity of the battery B,
Charging display setting voltage V ₁₃ will be automatically changed in association with the change of the charging current setting voltage V _12.

 Hereinafter, this emergency light lighting device will be described in more detail.

The charging power source I has a configuration similar to that of FIG. 1 and is configured to obtain DC power for charging. Then, the charging power supply I supplies a charging current to the battery B through the charging current intermittent switching elements Q ₁₁ and diode D _13.

Current detecting circuit II 'includes a resistor R ₂₁ for charging current detection interposed in series in the supply path of the charging current to the battery B, the difference detection circuit VIII for detecting a potential difference between both ends of the resistor R ₂₁
And an integrating circuit V 'for averaging the output voltage of the difference detecting circuit VIII, and a non-inverting amplifier VI' for non-inverting and amplifying the output voltage of the integrating circuit V '. Difference detecting circuit VIII is constituted by an operational amplifier OP ₁₄ and the resistor R ₂₂ to R _25. Integrator circuit V 'is composed of a resistor R ₂₆ and capacitor C _14. Non-inverting amplifier circuit VI 'includes an operational amplifier OP _11, resistors R _27, R
It consists of ₂₈ .

In this battery detection circuit II ', the resistance is proportional to the charging current.
The potential difference across the R ₂₁ is detected by the difference detection circuit VIII, 'as well as integration with a non-inverting amplifier circuit VI' the output voltage of the differential detection circuit VIII integration circuit V by amplifying, the non-inverting amplifier circuit VI ' From the output terminal of the average charging current corresponding voltage V ₁₁
Occurs.

Charge control circuit III 'includes an operational amplifier OP _12, resistors R _33, R ₃₄
And it is composed of a transistor Q _12. Then, resistors R ₂₉ and R ₂₉ connected to the output terminal of the display element driving power supply IV ′
The voltage at the middle point between the resistors R ₂₉ and R ₃₀ in the series circuit of R ₃₀ and R ₃₁ is input as the charging current setting voltage V ₁₂ , and the above average charging current corresponding voltage V ₁₁ and the charging current setting voltage V ₁₂ are compared. . As a result, charging the average charging current corresponding voltage V ₁₁ current setting voltage V
When less than _12, and the output of the operational amplifier OP ₁₂ to a high level to turn on the transistors Q _12, thereby to conduct the charging current intermittent switching elements Q _11, passing a charging current to the battery B. On the other hand, when the average charging current corresponding voltage V ₁₁ is higher than the charging current setting voltage V _12, causes the output of the operational amplifier OP ₁₂ is cut off the transistor Q ₁₂ in the low level. Thus it is cut off the charging current intermittent switching elements Q _11, the battery B
Cut off the supply of charging current to the battery.

More charging current intermittent switching element Q intermittent results _11, so that the average charging current supplied to the battery B is controlled constant value, i.e. in addition to compensating just enough self-discharge of the battery B.

Display control circuit VII 'includes an operational amplifier OP ₁₃ and resistor R ₃₂
In the configuration, the average charging current and the charging display setting voltage V ₁₃ obtained by dividing the charging current setting voltage V ₁₂ at the resistor R _30, R ₃₁ corresponding voltage V
Comparing the _11, average charging current corresponding voltage V ₁₁ is to conduct a display control switch element Q ₁₃ output becomes the high level of the operational amplifier OP ₁₃ when exceeding the charging display setting voltage V _13. As a result, the charge display element LED ₂ is turned on to indicate that the charge current to the battery B has a value that can sufficiently compensate for the self-discharge of the battery B.

If the charging current cannot be sufficiently obtained due to some abnormality (for example, a voltage drop of the commercial power supply E),
The average charging current corresponding voltage V ₁₁ does not exceed the charging display setting voltage V _13, operation output of the amplifier OP ₁₃ is turns off the charging display element LED ₂ by blocking the display control switch element Q ₁₃ becomes low level.

Display element driving power source IV 'is formed by a diode D ₁₁ and capacitor C _11, the display element driving power source IV'
After the voltage of stabilized with 3 terminal regulator RG, it applied to the charging display element LED _2. Accordingly, the brightness of the charging display element LED ₂ is constant. Incidentally, C _12, C ₁₃ is a capacitor.

Next, in the emergency light extinguishing device, the configuration and operation of a portion that detects a power failure and turns on the incandescent lamp L will be described.

Voltage of the commercial power supply E is the step-down is stepped down by the transformer T _1, further full-wave rectified by the full-wave rectifier DB _1, further diode D
₁₁ and smoothed by the capacitor C ₁₁ . Then, the voltage across the capacitor C ₁₁ is divided by the resistors R _51, R _52. This voltage is applied to the non-inverting input of the operational amplifier OP _15, operation from the output of the operational amplifier OP ₁₅ voltage output of the same value as the input voltage, through a resistor R ₅₃ and capacitor C ₁₆ for removing noise It applied to the non-inverting input of the amplifier OP _16. Incidentally, D ₁₂ is a diode for power isolation.

On the other hand, to the inverting input of the operational amplifier OP ₁₆ is 3 terminal Rejureta voltage output voltage dividing by the resistance R _54, R ₅₅ minute RG is applied, both are compared. AC power source E is normal, the voltage at the non-inverting input of the operational amplifier OP ₁₆ is higher than the voltage at the inverting input terminal, and conducts the transistors Q ₁₇ the voltage at the output terminal of the operational amplifier OP ₁₆ becomes a high level, As a result, the transistors Q ₁₆ , Q ₁₅ , and Q ₁₄ are turned off, and the incandescent lamp L is turned off. R ₄₈ , R ₄₉ , R ₅₀ , R ₅₆ and R ₅₇ are resistors.

Next, when the commercial power supply E fails, the divided voltage of the resistors R ₅₁ and R ₅₂ decreases. On the other hand, the three-terminal regulator RG is continuously supplied from the battery B through the diode D ₁₄ , and the resistors R ₅₄ and R ₅₂ since the divided voltage of ₅₅ remains intact, operation level of voltage at the non-inverting input terminal and an inverting input terminal is inverted amplifier OP _16, the voltage at the output terminal of the operational amplifier OP ₁₆ is in the low level transistor Q ₁₇ is cut off. As a result, the transistors Q ₁₆ , Q ₁₅ , and Q ₁₄ turn on and off in response to the output of the operational amplifier OP ₁₉ for lighting control, current is supplied to the incandescent lamp L, and the incandescent lamp L is turned on with the lighting controlled. Will be. As a result, the capacity of the battery B is effectively used.

 Next, the lighting control will be described.

When the commercial power supply E is power failure, as described above, it is performed failure detection transistor Q ₁₇ is turned off, when the power supply from the battery B to the incandescent lamp L starts, the voltage across the incandescent lamp L is the resistance R _36, R divided by _37, the potential difference across the resistor R ₃₆ is detected by the difference detecting circuit IX consisting of an operational amplifier OP ₁₇ and resistor R ₃₈ to R _41. Then, the difference detection circuit IX
After the output voltage of averaged by the integrating circuit X consisting of resistor R ₄₂ and capacitor C _15, the operational amplifier OP ₁₈ and resistor R _43,
It is amplified by the noninverting amplifier AP consisting R _44. further,
The output voltage of the non-inverting amplifier AP is compared with the voltage at the middle point between the resistors R ₄₆ and R _{45 in} the operational amplifier OP ₁₉ . Note that R
₄₇ is a resistor.

By the above operation, the average value of the voltage across the incandescent lamp L is smaller than the reference value, the output voltage of the operational amplifier OP ₁₉ turns on the transistor Q _16, Q _15, Q ₁₄ in the high level to the incandescent lamp L perform power supply, the average value of the voltage across the incandescent lamp L is larger than the reference value, the output voltage of the operational amplifier OP ₁₉ turns off the transistors Q _16, Q _15, Q ₁₄ in the low level to the incandescent lamp L Stop supplying power to As a result,
The average value of the voltage applied to the incandescent lamp L is controlled to a predetermined constant value. Therefore, the amount of light of the incandescent lamp L at the beginning of a power failure can be suppressed, the capacity of the battery B can be used effectively, and the incandescent lamp L can be maintained at a required illuminance for a long time. In addition,
The length of the ON period of the transistor Q ₁₄ becomes longer as the voltage of the battery B is reduced, the transistor Q ₁₄ drops to a certain extent become continuously turned on. Further, on-off period of the transistor Q _14, if appropriately setting the time constant of the integrating circuit X, a level that does not feel flicker an incandescent lamp L is sufficiently short.

The effect of the charging device in this embodiment is the same as that of the first embodiment.

〔The invention's effect〕

According to the charging device of the present invention, the display control switch element is interposed between the charging display element and the display element driving power supply, and the charging display setting voltage is compared with the average charging current corresponding voltage. Is provided with a display control circuit that turns on the display control switch element when the charging display setting voltage is exceeded, so that the charging current flows through the battery with a value sufficient to compensate for the self-discharge of the current. The charge display can be performed only at the time.

Moreover, since the charge display set voltage is changed in accordance with the change of the charge current set voltage while maintaining a predetermined ratio of 1 or less with respect to the charge current set voltage, the charge current determined according to the capacity of the battery is changed. The charge display setting voltage is changed in conjunction with the change of the set voltage, so that it is only necessary to change the charge current set voltage with respect to the change of the battery capacity, and it is possible to easily respond to the change of the battery capacity. it can.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a first embodiment of the present invention;
FIG. 2 is a characteristic diagram showing a relationship between a charging current and a power supply voltage, and FIG.
FIG. 5 is a circuit diagram showing a configuration of a second embodiment of the present invention.
FIG. 1 is a circuit diagram showing a configuration of a conventional example. I: power supply for charging, II: current detection circuit, III: charging control circuit, IV: power supply for driving the display element, VII: display control circuit, B: battery, Q _1: for intermittent charging current Switch element, LED ₁ …… Charge display element, Q ₃ …… Switch element for display control

Claims (1)

(57) [Claims] A charging power supply for supplying a charging current to a battery;
A charging current intermittent switch element inserted in series in a supply path of the charging current from the charging power supply to the battery, a current detection circuit that detects the charging current and generates an average charging current corresponding voltage; Comparing the average charging current corresponding voltage output from the circuit with the charging current setting voltage, and when the average charging current corresponding voltage is lower than the charging current setting voltage, turns on the charging current intermittent switch element; A charge control circuit that controls the average charge current to a constant value that compensates for the self-discharge of the battery by shutting off the charge current switching element when the corresponding voltage is higher than the charge current set voltage, and a charge display element. ,
A display element driving power supply for driving the charging display element, a display control switch element interposed between the display element driving power supply and the charging display element, and a charge current setting voltage of 1 or less. A charge display setting voltage that changes with a change in the charging current setting voltage while maintaining a predetermined ratio is compared with the average charging current corresponding voltage, and when the average charging current corresponding voltage is larger than the charging display setting voltage. And a display control circuit for conducting the display control switch element.