JPH0584134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a charging device for a battery-powered vacuum cleaner used in general households.

BACKGROUND ART Conventionally, a charging device for a battery-powered vacuum cleaner of this type has generally had the configuration shown in FIG. The conventional technology will be explained below based on the drawings.

FIG. 4 shows an embodiment of a conventional charging device. In the figure, it is assumed that a pulsating current obtained by full-wave rectification of an AC power source is applied between terminals 1 and 2, which are connected to a charging adapter. Here, between terminals 1 and 2, there is a main thyristor 1 and a battery 2.
are connected in series. Diode 3 is battery 2
This element is inserted between the anode of the battery 2 and the cathode of the main thyristor 1 to prevent reverse discharge.

The diode 4 and capacitor 5 smooth the full-wave rectified power supply, and the second thyristor 6 is kept in the on state when turned on.

Gate resistor 7 is connected to the gate terminal of main thyristor 1.
is connected, and between the gate and cathode,
A gate sensitivity adjustment resistor 8 is connected.

Main thyristor 1 cathode terminal (point A) and
A Zener diode 9 and a resistor 1 are connected between the GND terminals.
0 are connected in series, one end of a resistor 11 is connected to the connection point between the anode terminal of the Zener diode 9 and the resistor 10, and the other end is connected to the gate terminal of the second thyristor 6. Also, smoothing capacitor 5
Resistors 12 and 13 and a light emitting diode 1 are connected to both ends of the
4 are connected in series. Also, resistors 12 and 13
The anode terminal of the diode 15 is connected to the connection point, and the cathode terminal at the other end is connected to the anode terminal of the second thyristor 6. Furthermore, a resistor 16 is connected between the anode and cathode of the main thyristor 1.

In the above circuit configuration, a gate current flows into the gate terminal of the main thyristor 1 from the DC power supply through the gate resistor 7, so that the main thyristor 1 is turned on. (When the battery is not charged) That is, a charging current flows into the battery 2 via the main thyristor 1 and the diode 3, thereby sustaining charging. At this time, the light emitting diode 14 lights up because a current flows through the resistors 12 and 13. Diode 15 is now reverse biased and cut off.

Here, as the battery 2 continues to be charged, the voltage between the terminals of the battery 2 gradually increases, and when it approaches a certain set potential (charging completion potential), the Zener diode 9 enters the stable region, and the Zener diode 9 Zener current flows through the resistor 10, and the voltage between the terminals of the resistor 10 increases. This voltage between the terminals of the second thyristor 6
When the gate trigger voltage is reached, the gate current flows through the resistor 11 and the second thyristor 6 turns on.
state. Here, the second thyristor 6 is turned on.
Then, the gate potential of the main thyristor 1 is pulled lower than the cathode potential, so the main thyristor 1 becomes OFF and stops charging. Further, when the second thyristor 6 is turned on, the light emitting diode 14 is also turned off because the diode 15 becomes conductive. Even if main thyristor 1 turns OFF,
A weak current flows through the battery through the resistor 16, and supplementary charging is performed.

FIG. 5 shows the charging characteristics of the second circuit. In the figure, a shows how the terminal voltage of the battery increases over time, and when it reaches the set potential of the Zener diode 9, the main thyristor 1 turns off. Figure b shows the relationship between battery charging current and time, and shows how the current is cut off when charging is complete. However, since the supplementary charging of the resistor 16 is continued, the voltage between the terminals of the battery increases again.

Problems that the invention aims to solve: However, if the battery is left connected to a load (such as an electric blower) for a long time during use, the internal resistance of the battery increases, and the battery is left unused for one to three months. In this case, the internal resistance can reach several hundred ohms. If an attempt is made to charge such an over-discharged battery using the conventional charging circuit described above, a problem will occur.
This situation is shown in FIG.

FIG. 6a shows a case where the internal resistance 17 of the battery 2 increases. At this time, when this battery is connected to the charging circuit, the charging current I flows because the resistance value R of the internal resistor 17 is large. Then, the apparent voltage between the terminals of the battery 2 is generated to be high, and as shown in b and c, charging is stopped immediately after the start of charging. This is because the charging circuit shown in FIG. 4 detects the potential at point A. As described above, over-discharged batteries cannot be charged using conventional charging circuits, which has been a major dissatisfaction for users. Also, in the market, battery over-discharge phenomenon is not a problem that occurs easily, but if
When this occurs, the battery must be replaced, which is always problematic from an economical point of view.

As described above, conventional charging devices have the problem of not being able to charge over-discharged batteries.
The present invention aims to overcome these conventional drawbacks and improve the charging device so that it is possible to charge even a battery that has been over-discharged.

Means for Solving the Problems In order to solve the above problems, the present invention detects that when an over-discharged battery is connected, the voltage between the terminals of the battery becomes abnormally high, and instantly converts the voltage to an inverter. This is a measure to prevent the battery from inverting at an abnormally high potential and issuing a charge completion signal.If a normal battery (one that has not been over-discharged) is connected, it will continue to operate as before. If an over-discharged battery is connected, a potential higher than the charging completion potential will be generated, so this voltage is detected, the peak of the waveform is inverted by an inverter, and the voltage is suppressed below the charging completion potential, allowing charging to progress to some extent. , when the internal resistance decreases and the peak potential falls below the charge completion potential,
This is intended to control the circuit to switch to the normal operating mode.

Effects The present invention is configured so that even when an over-discharged battery is connected to a charging circuit, charging can be completed without any problem by using the above-described means.

Embodiments Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of the charging device of the present invention. In the figure, a full-wave rectified power supply is applied between terminals 1 and 2. Between terminals 1 and 2, a main thyristor 101, a diode 102,
A battery 103 is connected in series, and a gate resistor 104 is connected between the gate and anode of the main thyristor.
However, there is also a sensitivity adjustment resistor of 10 between the gate and cathode.
5 is connected. Resistor 106 is a bypass resistor for supplementary charging. Further, a Zener diode 107 and a second thyristor 108 are connected in series to the gate terminal of the main thyristor 101. terminal 1,
Further, resistors 109 and 110 and a light emitting diode 111 are connected in series between the resistors 109 and 110, and the anode of the diode 112 is connected to the connection point between the resistors 109 and 110, and the cathode side is connected to the anode terminal of the second thyristor 108. It is connected to the.

A series circuit of a Zener diode 113 and a resistor 114 is connected to the cathode terminal of the main thyristor 101, one end of a resistor 115 is connected to the connection point between the anode of the Zener diode 113 and the resistor 114, and the other end is connected to a transistor 116. Further, a resistor 122 is connected to the collector of the transistor 116, and these constitute an inverter (inversion circuit). Furthermore, a resistor 1 is connected between the cathode terminal of the main thyristor 101 and GND.
17, a series circuit of a Zener diode 119 and a resistor 120 is connected via a diode 118. Zener diode 119 anode terminal and
An electrolytic capacitor 121 is connected between GND,
A resistor 122 is connected to the anode of the electrolytic capacitor 121.
It is connected to the collector of transistor 116 via. Further, one end of a resistor 123 is connected to the connection point between the anode of the Zener diode 119 and the resistor 120, and the other end is connected to the gate terminal of the second thyristor 108. Diode 124 is connected between the cathodes of Zener diodes 119 and 107 as shown.

In the above circuit configuration, the principle of charging is the same as in the conventional example, and the charging current is supplied from the terminal 1 to the battery 10 via the main thyristor 101 and the diode 102.
It is configured to flow into 3. However, this is a case where a regular battery that is not an over-discharged battery is connected, and when an over-discharged battery is connected, charging could not be performed in the conventional example.

The operation will be described below only when an over-discharged battery is connected. When an over-discharged battery is connected, the potential at point a in FIG. 1 shows an abnormally high peak value. This is because the internal resistance of the battery 103 is increasing, so the charging current is kept low, and
This is because the voltage between the terminals of the battery 103 is increased by the internal resistance.

FIG. 2 shows voltage waveforms at various parts in this case. In the figure a, the voltage waveform at point a is the voltage waveform of the battery 103.
It can be seen that the peak value of the full-wave rectified power source is higher than the charging completion potential I when the regular battery 103 is connected due to the influence of the internal resistance. However, in this case, the Zener diode 113
If the setting is made so that the potential at point a enters the operating range only when the potential is higher than the charging completion potential I, the base current flows into the transistor 116 via the Zener diode 113, turning it on. but,
When the regular battery 103 is connected, the peak at point a does not appear, so the transistor 116 is turned off.
The condition remains.

That is, only when the potential at point b exceeds the charging completion potential I, as shown by the broken line in FIG. 2a, the transistor 116 is turned on and the waveform is inverted. However, since an electrolytic capacitor 121 is connected to point b, the potential is actually smoothed as shown in FIG. That is, even if an over-discharged battery 103 is connected, the potential at point b will not exceed the charging completion potential I, and charging will continue.
Here, when charging progresses to a certain extent, the overdischarged battery 10
The internal resistance of No. 3 gradually decreases, the peak value gradually decreases, and finally the peak value falls below the charge completion potential. In this case, transistor 116 will be cut off and will operate as if a normal battery were connected. This situation is shown in FIG. 2b. I' is the charging completion potential at point a, and I' is the charging completion potential at point b, which is lower by the voltage drop of resistor 117 and diode 118, and _VZ of Zener diode 119.
It is set by

That is, when the potential at point b reaches the level of
The second thyristor 108 is similar to the configuration of the conventional example.
The main thyristor 101 turns OFF and charging is completed. At this time, the light emitting diode 111 is turned off at the same timing as the second thyristor 108 is turned on.

FIG. 3 shows the charging characteristics when the over-discharged battery 103 is connected.

In the figure, a shows the voltage waveform at point a, and b shows the voltage waveform at point b. When an initially over-discharged battery is connected, the voltage at point a shows a high peak value. However, since the transistor 116 turns on near the peak value, the potential at point b is kept low and falls below the charging completion potential', and charging is continued. When charging progresses to a certain extent, the internal resistance of the battery 103 decreases, and the peak value of a decreases, and conversely, the charging current to the battery increases, and at a certain point, the transistor 116 turns off. From now on, charging will be completed using the same principle as when a regular battery is connected.

Effects of the Invention As described above, according to the present invention, since charging can be performed regardless of the state of the battery, there is no problem even if the user accidentally connects the battery to a load for a long time. In addition, the reliability of the charging circuit is greatly improved, and the cost can be reduced, making it highly practical.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a charging device showing an embodiment of the present invention, FIGS. 2 and 3 are graphs showing operating waveforms of each part of the embodiment of the present invention, and FIG. 4 is a conventional charging device. The circuit diagrams of the device, FIGS. 5 and 6, are explanatory diagrams showing operating waveforms of each part of a conventional charging device. 101... Main thyristor, 103... Battery, 1
08...Second thyristor, 111...Light emitting diode, 119...Zena diode.

Claims (1)

[Scope of Claims] 1. A series circuit of a main thyristor and a battery connected to a rectified power supply, and a second thyristor connected between the gate terminal of the main thyristor and the ground to shut off the main thyristor when charging is completed. , a second thyristor is provided which is turned on by detecting the point of completion of charging by a terminal voltage detection section of the battery, and detects an abnormal peak voltage that occurs when the internal resistance of the voltage between the terminals of the battery increases; A charging device for a battery-powered vacuum cleaner, comprising a control device that enables circuit-based charging to continue when an abnormal peak voltage detection section is activated. 2. The abnormal peak voltage detection unit consists of a peak value detection unit for the voltage between terminals of the battery and an inverter (inverting circuit) connected to it, and is controlled so that the peak value does not exceed the charging completion voltage. Claim 1
A charging device for a battery-powered vacuum cleaner as described in .