JPH07123608A - Cordless apparatus - Google Patents

Abstract

PURPOSE:To realize a cordless apparatus capable of preventing the breakdown of elements by overcharge. CONSTITUTION:It is possible to supply current to a second load 34, when a cord 22 is either connected or removed, by controlling first and second transistors 27 and 28 in accordance with the condition whether a control circuit 35 is connected to the cord 22 or not. Besides, a capacitor element 32 is charged until a full-charge detecting means 38 detects full charge when the cord 22 is connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless device applicable to products such as jar pots. That is, the present invention relates to a device that can be used by plugging a power plug into an outlet to charge it, and then disconnecting the power plug from the outlet when the charging is completed and using the cordless state.

[0002]

2. Description of the Related Art A general cordless device conventionally used will be described with reference to FIG. Cordless equipment
It is composed of a detachable commercial 100V AC power source 1, a transformer 2 and a rectifier circuit 3 for converting the AC power source 1 into a low voltage of about 10V, a secondary battery charged by the rectifier circuit 3 and a large-capacity capacitor. The power storage device 4 includes a power storage device 4, a load 5 connected to the power storage device 4, and a switch 6 for turning on / off a current of the load 5.

With the above configuration, the cordless device operates as follows. When there is a cord to which the AC power supply 1 is connected, the AC power supply 1 to the transformer 2
A charging current is supplied to the storage element 4 via the rectifier circuit 3. When the switch 6 is closed in this state, the transformer 2
From the rectifier circuit 3 is also supplied to the load 5, and the load 5 operates with the cord. When the switch 6 is closed with the AC power source 1 removed, the load 5 is supplied with the electric charge stored in the storage element 4 and operates in a cordless state.

[0004]

In the conventional structure described above, when the battery is charged for a long time while the AC power source is still connected, the storage element is overcharged and the performance is deteriorated or severe. Has a problem of destruction, overheating, flame or ignition.

The present invention is intended to solve such a problem, and a first object of the present invention is to provide a safe cordless device capable of automatically stopping charging of a power storage element when charging is completed. Is.

Further, in relation to the first object, when a predetermined time elapses from the stage where the charging is once completed, the charging is automatically performed again, and the storage element can always store almost a full charge. The second purpose is to provide a cordless device.

[0007]

A first means for achieving the first object of the present invention is to provide a current supply circuit comprising a removable AC power supply, a switching element, and a series circuit of a load, and the current. A storage element connected to the supply circuit, a full-charge detection means for detecting full charge of the storage element, and a drive circuit for controlling on / off of the switching element are provided, and the drive circuit receives a signal from the full-charge detection means. Cordless device that receives and turns off the switching element A cordless device that solves the above problems is provided.

A second means of the present invention for achieving the second object is to provide a current supply circuit comprising a series circuit of a removable AC power supply, a switching element and a load, and a storage connected to the current supply circuit. An element, a full-charge detecting means for detecting full charge of the storage element, a drive circuit for controlling ON / OFF of the switching element, and a time limit means connected to the drive circuit, wherein the drive circuit detects full charge. The switching element is turned off in response to a signal from the means, and the time-out means inputs an ON signal to the driving circuit to turn on the switching element when a predetermined time has elapsed after the driving circuit turned off the switching element. It is a cordless device that is turned on again.

[0009]

According to the first means of the present invention, when the full-charge detecting means detects that the storage element is fully charged, it acts so as to turn off the switching element, so that there is no fear of damage due to overcharging. It will be realized.

In the second means of the present invention, when the full charge detecting means detects that the storage element is fully charged, it acts so as to turn off the switching element, and the time limit means further elapses a predetermined time from this point. It is intended to realize a cordless device in which charging of the power storage element is started again at a stage and the power storage element can always store almost full electric charge.

[0011]

EXAMPLES Examples of the first means of the present invention will be described below.
It will be described with reference to FIG. This embodiment relates to a jar pot that enables cordless hot water supply. Commercial 10
The 0V AC power supply 21 can be attached to and detached from the heat retention heater 23 that constitutes the first load 24 by a detachable magnet-type cord 22 (hereinafter simply referred to as a cord 22) attached to the jar pot. It is connected to the. The AC power source 21, the cord 22, and the first load 24 form a current supply circuit 25. A rectifier circuit 26 is connected to the current supply circuit 25, and rectifies the AC voltage reduced by the first load 24 into DC. Rectifier circuit 2
6 has the same N as the first NPN type transistor 27.
A series circuit of PN type second transistors 28 is connected. Further, a first reverse conducting diode 29 is provided between the collector and the emitter of the first transistor 27,
A second reverse conducting diode 30 is connected between the collector and emitter of the second transistor 28. Further, between the collector and the emitter of the first transistor 27, a storage element 32 composed of a choke coil 31 and an electric double layer capacitor, and a full charge detection means 38 for detecting full charge of the storage element 32 are connected. is doing. The full charge detection means 38 is composed of a constant voltage diode 40 and a photocoupler 41. When the storage element 32 is fully charged, the input side of the photocoupler 41 is reached when the zener voltage of the constant voltage diode 40 is exceeded. A current flows through the output side, and an off signal is emitted from the output side. In addition, the switching element 3
7 is driven by a drive circuit 39 which operates in response to the signal from the full charge detection means 38. In the present embodiment, a triac is used as the switching element 37, and the drive circuit 39 operates so as to turn off the switching element 37 when receiving the signal from the full charge detecting means 38.

A motor for hot water supply 33 for a jar pot, which constitutes a second load 34, is connected to both ends of the series circuit of the first transistor 27 and the second transistor 28 via a switch 36. . Further, the control circuit 35 detects the output voltage of the current supply circuit 25 and determines whether the first transistor 2 is connected depending on whether the AC power supply 21 is connected.
7 and the second transistor 28 are on / off controlled.

The operation of this embodiment will be described below. When the AC power supply 21 is connected by the cord 22, a voltage stepped down to an appropriate size by the first load 24 is supplied from the AC power supply 21 to the rectifier circuit 26. In this state, the charging of the storage element 32 has hardly progressed, so that the voltage between the terminals is low, and the full charge detection means 38 is not operating. Therefore, the drive circuit 39 controls the switching element 37 to be turned on. At the same time, the output of the rectifier circuit 26 is also supplied to the second load 34 via the switch 36. Therefore, when the user turns on the switch 36, the hot water supply motor 33 that constitutes the second load 34 is driven to extract hot water that is being kept warm from the spout of a jar pot (not shown). . That is, the cordless device of this embodiment can be used with a cord. At this time, the control circuit 35 detects that the switch 36 is turned on, and in this state, the base current is not supplied to the second transistor 28. That is, the second transistor 28 is off. When the switch 36 is not turned on, the control circuit 35 supplies the base current to the second transistor 28, and the rectifier circuit 26
Causes a current to flow to the second transistor 28, and this current flows to the storage element 32 via the choke coil 31. That is, the storage element 32 is charged. This storage element 32
When the charging of the battery progresses to a fully charged state, the fully charged detection means 3
8 transmits this information to the drive circuit 39, and the drive circuit 39
Controls the switching element 37 to off.
That is, when the voltage between the terminals of the storage element 32 exceeds the Zener voltage of the constant voltage diode 40 that constitutes the full-charge detection unit 38, a current flows to the input side of the photocoupler 41 and the output side becomes conductive, which causes The off signal is transmitted to the drive circuit 39. The drive circuit 39 turns on the switching element 37 when the output side of the photocoupler 41 is open, and turns off the switching element 37 when the output side of the photocoupler 41 is short-circuited. Therefore, the switching element 37 is the storage element 32.
Is turned off when the battery is fully charged, and is not overcharged any more.

When the second transistor 28 is on, the current from the second transistor 28 is flowing in the choke coil 31 as described above, and the control circuit 35 is in the second state. At the moment when the transistor 28 is turned off, the magnetic energy stored in the choke coil 31 circulates between the first reverse conducting diode 29 and the storage element 32, and reverses between the collector and the emitter of the first transistor 27. No voltage is applied.

As described above, when the AC power supply 21 is connected by the cord 22, the current from the current supply circuit 25 is applied to the first load 24, the second load 34, and the storage element 3
2 is supplied. In this way, the storage element 32 is charged to the fully charged state, and the second load 34 can be freely operated with the cord provided by turning on the switch 36.

Next, the operation when the cord 22 is removed and the AC power source 21 is not connected will be described.
In this state, the control circuit 35 outputs a signal that repeats high and low outputs to the first transistor 27 at about 30 kHz. Therefore, the first transistor 27 is repeatedly turned on and off at about 30 kHz. When the first transistor 27 is on, current flows from the fully charged storage element 32 to the choke coil 31 and the first transistor 27. When the first transistor 27 is turned off after a lapse of a predetermined time (for example, 20 μsec) by the control circuit 35, the current flowing in the choke coil 31 until now is changed by the magnetic energy stored therein. , Does not suddenly become zero, and is supplied to the second load 34 via the second reverse conducting diode 30. Therefore, the stored energy of the choke coil 31 gradually decreases,
The control circuit 35 turns on the first transistor 27 again after a predetermined time, so that the charging current from the storage element 32 is supplied again. Thus the control circuit 3
The charging current stored in the storage element 32 is supplied to the second load 34 by repeating the on / off of the first transistor 27 by the transistor 5.

That is, with the cord 22 removed,
The operation is as a boost chopper. Therefore,
When the control circuit 35 changes the ON / OFF ratio of the first transistor 27, the ratio of the voltage supplied to the second load 34 to the voltage of the storage element 32 can be adjusted. The first load 24 is of course the storage element 32.
It is not supplied with electric current from.

As described above, in the present embodiment, the control circuit 35 controls the first transistor 27 and the second transistor 28 in accordance with the condition of whether the cord 22 is connected or not, and the code 22 The electric current can be supplied to the second load 34 both when it is connected and when it is disconnected.

Particularly, in this embodiment, since the heat retention heater 23 required for a normal jar pot is used as the first load 24, it is necessary to provide a transformer having a large weight, price and volume. There is no such thing.

Next, an embodiment of the second means of the present invention will be described with reference to FIG. In this embodiment, the time limit means 42 connected to the drive circuit 39 is provided. That is, when the storage element 32 is fully charged, the drive circuit 39 turns off the switching element 37 by an off signal from the full charge detection means 38, and the time limit means 42 causes the drive circuit 39 to turn off the switching element 37. After a predetermined time (10 seconds in this embodiment)
When is passed, the ON signal is input to the drive circuit 39. In this way, the drive circuit 39 controls to turn on the switching element 37 again.

The operation of this embodiment will be described below. The process of charging the storage element 32 with the current from the current supply circuit 25 is exactly the same as in the case of FIG. Power storage element 3
When the terminal voltage of 2 reaches a predetermined value, the full charge detection means 3
8 transmits this information to the drive circuit 39, and the drive circuit 39
Turns off the switching element 37. At the same time, means 4
2 starts transmitting time from the time when the switching element 37 is turned off by the drive circuit 39, and transmits an on signal to the drive circuit 39 again after 10 seconds have elapsed. In this way, the drive circuit 39 turns on the switching element 37 again. During these 10 seconds,
The electric storage element 32 is charged to compensate for the discharged electric charge. When the storage element 32 reaches full charge again in this way, the full charge detection means 38 operates and the drive circuit 39 turns off the switching element 37.
Thereafter, such an operation is repeated, and as a result, the storage element 3
No. 2 can always maintain the fully charged state.

As described above, the present embodiment has the following features because the time limit means 42 is provided.

In general, when the charging current is flowing, the storage element 32 tends to have a slightly higher terminal voltage due to the effect of the voltage drop due to the internal resistance. Only then does the phenomenon that the terminal voltage drops. Therefore, if it is attempted to detect the full charge of the storage element 32 having such characteristics with the terminal voltage, it is not preferable because only one threshold value causes an oscillation operation with a short period. That is, once the threshold value is reached and full charge detection is performed and charging is stopped, the terminal voltage of the storage element 32 drops at that moment and falls below this threshold value again. That is, the full-charge detection signal disappears, and the charging operation is repeated in a very short cycle.

In this respect, in the present embodiment, since the time limit means 42 is provided, such a situation that such an oscillation operation is repeated in a short period does not occur. That is, the next charging operation is always started after 10 seconds, and therefore, when the switching element 37 having a contact is used, the durability of this contact can be enhanced and the life can be extended. is there.

In each of the above embodiments, the triac is used as the switching element 37. However, the triac is not limited to the triac, and the point is that the output of the current supply circuit 25 can be turned on / off. It doesn't matter. Further, the first load 24 is not limited to the heat-retaining heater for the jar pot, and any one having an impedance used for the equipment can be used.

[0026]

The first means of the present invention is to provide a current supply circuit comprising a series circuit of a removable AC power source, a switching element and a load, a storage element connected to the current supply circuit, and a storage element of this storage element. Full charge detection means for detecting full charge, and a drive circuit for controlling ON / OFF of the switching element, the drive circuit is configured to turn off the switching element in response to a signal from the full charge detection means. It is possible to realize a highly reliable cordless device without fear of the element being destroyed.

A second means of the present invention is a current supply circuit comprising a series circuit of a removable AC power supply, a switching element and a load, and a storage element connected to the current supply circuit.
A full charge detection means for detecting full charge of the storage element, and a drive circuit for controlling ON / OFF of the switching element,
A time period means connected to the drive circuit, the drive circuit receives a signal from the full-charge detection means and turns off the switching element, and the time period means performs a predetermined period after the drive circuit turns off the switching element. When time passes,
As a configuration in which an ON signal is input to the drive circuit to turn on the switching element again, there is no fear of destruction of the element due to overcharging, and the electric charge of the storage element is always in a fully charged state, which is stable especially in a cordless state It is possible to realize a cordless device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a cordless device that is an embodiment of the first means of the present invention.

FIG. 2 is a circuit diagram showing a cordless device which is an embodiment of the second means of the present invention.

FIG. 3 is a circuit diagram of a cordless device in the related art.

[Explanation of symbols]

 21 AC power supply 22 Code 24 First load 25 Current supply circuit 32 Storage element 34 Second load 38 Full charge detection means 39 Drive circuit 42 Timed means

Claims (2)

[Claims] 1. A current supply circuit comprising a series circuit of a detachable AC power supply, a switching element and a load, a storage element connected to the current supply circuit, and a full-charge detection means for detecting a full charge of the storage element. And a drive circuit for controlling ON / OFF of the switching element, wherein the drive circuit receives the signal from the full charge detection means and turns off the switching element. 2. A current supply circuit comprising a series circuit of a detachable AC power supply, a switching element and a load, a storage element connected to the current supply circuit, and a full charge detection means for detecting a full charge of the storage element. And a drive circuit for controlling ON / OFF of the switching element, and a time means connected to the drive circuit. The drive circuit turns off the switching element in response to a signal from the full charge detection means, and the time means. Is a cordless device that turns on the switching element again by inputting an ON signal to the driving circuit when a predetermined time has passed since the driving circuit turned off the switching element.