JP5075594B2 - Electrical equipment - Google Patents

Description

  The present invention relates to an electric device that uses a voltage obtained by stepping down a commercial power supply to a predetermined voltage using a power transformer type AC adapter, and performs load driving and secondary battery charging in parallel. The present invention relates to an electric device that can suppress the generation of beat noise and reduce costs.

  For example, Japanese Patent No. 2555323 discloses a small electric device that includes a secondary battery that is charged using a commercial power source in a power supply unit and that simultaneously charges the secondary battery and drives a load.

This conventional electric device includes an inverter circuit, and in the inverter circuit, power supply means for converting the frequency and voltage value of a commercial power supply, and a load unit connected to the power supply means and supplied with driving power And means for detecting the load amount of the load section; and control means for maintaining the driving state of the load section in a preset state in correspondence with the magnitude of the load amount detected by the detection means; And means for limiting the amount of current output from the power supply means in conjunction with the load amount detection operation in the detection means, and the load portion is constituted by a secondary battery and other loads, By always connecting the battery to the power supply means, load driving and charging are performed in parallel.
Japanese Patent No. 2555323

  However, in the technique disclosed in Patent Document 1 described above, an inverter circuit is provided in the electric device, and the load is driven and charged by stepping down to a predetermined voltage while switching at high frequency. Therefore, when it is applied to a small electric device such as an electric razor, it is difficult for the user to operate.

  In addition, since the inverter circuit is switching at high speed, noise is likely to occur, and noise countermeasures are required, leading to an increase in cost. Furthermore, since there is a commercial power supply voltage in the electric equipment, for example, when applied to an electric shaver that can be washed with water, there is a risk of electric shock during washing.

  In recent years, an electric shaver or the like that performs load (motor) driving and secondary battery charging in parallel using a voltage obtained by stepping down a commercial power supply to a predetermined voltage using a power transformer or a switching power supply type AC adapter. Many devices have been put into practical use. When a switching power supply type AC adapter is used, noise is likely to occur because switching is performed at a high frequency inside the AC adapter, and noise countermeasures are required, leading to an increase in cost.

  When a power transformer type AC adapter is used, output is supplied from the AC adapter at a commercial power cycle (50 [Hz] / 60 [Hz]), so the load (motor) is driven at the same frequency. Doing so will cause beats due to voltage fluctuations.

  When a power transformer type AC adapter is used, it has been experimentally found that when a load (motor) is driven at a driving frequency of 1 [kHz] or higher, no motor sound can be heard, for example, driving at about 2 [kHz]. A load (motor) is driven at a frequency. However, since the driving frequency is as high as about 2 [kHz], a switching loss in the switching element for intermittent driving is large, and the switching element easily generates heat. For this reason, it is necessary to use a switching element having a low on-resistance or a switching element having a high rating, leading to an increase in cost.

  The present invention has been made in view of the above-described conventional circumstances, and uses a voltage obtained by stepping down a commercial power source to a predetermined voltage using a power transformer type AC adapter, and performs load driving and charging of a secondary battery. An object of the present invention is to provide an electric device which is performed in parallel, which suppresses the generation of noise and also suppresses the generation of a roaring sound and can reduce costs.

In order to achieve the above object, an electrical device according to the present invention includes a secondary battery and a load, and uses the output from an AC adapter including a transformer that steps down a commercial power source to a predetermined voltage. An electric device for charging a battery and driving the load, the switching element for controlling supply of the AC adapter output to the secondary battery and the load, and on / off control of the switching element, the commercial device A control unit that performs a frequency of 1 [kHz] or less that is not a multiple of a power supply frequency; and a voltage detection unit that detects a voltage of the secondary battery, wherein the control unit detects the secondary detected by the voltage detection unit. set the initial value of the oN time of the switching element at the start of the on / off control of the switching element in accordance with the voltage of the battery, the voltage detection by the voltage detecting means Wherein the first, characterized in that to gradually vary the ON time of the control cycle of the switching elements for each.

The electrical apparatus according to the present invention, the lower the voltage of the secondary battery detected by said voltage detecting means, the initial value of the on-time is the second feature of Rukoto is set longer.

The electric device according to the present invention is characterized in that the voltage detection unit detects the voltage of the secondary battery at a timing immediately before the switching element is turned on .

In addition, an electrical device according to the present invention includes a secondary battery and a load, and uses the output from an AC adapter including a transformer that steps down a commercial power source to a predetermined voltage, and charges the secondary battery and the load. The switching device that controls the supply of the AC adapter output to the secondary battery and the load and the on / off control of the switching device are not a multiple of the commercial power frequency. Control means for performing at a frequency of 1 [kHz] or less, battery remaining capacity detecting means for detecting the remaining capacity of the secondary battery, and voltage detecting means for detecting the voltage of the secondary battery , the control means comprising: The on-time of the switching element when starting the on / off control of the switching element according to the remaining capacity of the secondary battery detected by the battery remaining capacity detecting means Set the value, the fourth feature that is gradually varying the on-time in the control cycle of the switching element for each voltage detection by the voltage detecting means.

Furthermore, electrical equipment according to the present invention, the higher the residual battery capacity of the secondary battery detected by the battery remaining capacity detection means is small, the initial value of the on-time is set longer and the fifth characterized Rukoto To do.
The electric device according to the present invention is characterized in that the load is a motor.

In the electrical device having the first feature according to the present invention, the on / off control of the switching element is performed at a frequency of 1 [kHz] or less that is not a multiple of the commercial power supply frequency. It is possible to suppress the occurrence of beat noise by suppressing fluctuations, and to suppress the generation of noise by intermittent driving at a low frequency, and as a result, it is possible to realize an electric device that can achieve cost reduction. Also, every time the battery voltage is detected by the voltage detecting means, the on-duty in the on / off control of the switching element by the control means is gradually changed. Further suppression can be achieved. Furthermore, since the initial value of the on time of the switching element when starting the on / off control of the switching element is set according to the voltage of the secondary battery detected by the voltage detecting means, it is as short as possible from the start of driving the load. Thus, the predetermined voltage can be reached, and as a result, the time zone during which the battery voltage fluctuates can be further shortened, and the generation of a roaring sound can be suppressed.

In the electrical device having the second feature according to the present invention, the initial value of the on-time is set longer as the voltage of the secondary battery detected by the voltage detection means is lower. The predetermined voltage can be reached over time, and as a result, the time zone in which the battery voltage fluctuates can be shortened, and the generation of a roaring sound can be suppressed.

In the electrical device having the third feature according to the present invention, the voltage detection unit detects the voltage of the secondary battery at a timing immediately before the switching element is turned on, so the battery voltage of the secondary battery by the voltage detection unit is The detection accuracy can be increased and more stable charge control and load drive control of the secondary battery can be performed.

In the electric device having the fourth feature according to the present invention, the on / off control of the switching element is performed at a frequency of 1 [kHz] or less that is not a multiple of the commercial power supply frequency. Therefore, it is possible to suppress the occurrence of beat noise by suppressing a large voltage fluctuation, and it is possible to suppress the generation of noise by intermittent driving at a low frequency, and as a result, it is possible to realize an electric device capable of reducing the cost. In addition, the initial value of the on time of the switching element when starting the on / off control of the switching element according to the remaining capacity of the secondary battery is set, and the control period of the switching element is set every time the voltage of the secondary battery is detected. Since the ON time is gradually changed, the predetermined voltage can be reached in as short a time as possible from the start of driving the load. As a result, the time period during which the battery voltage fluctuates can be further shortened, and the generation of a roaring sound is prevented. Can be suppressed.

Furthermore, in the fifth electrical apparatus according to the present invention, the smaller the battery remaining capacity of the secondary battery detected by the battery remaining capacity detection means, since the initial value of the ON time is set longer, the start of driving the load The predetermined voltage can be reached in as short a time as possible, and as a result, the time zone in which the battery voltage fluctuates can be further shortened, and the generation of a roaring sound can be suppressed.
Moreover, the 6th electric equipment which concerns on this invention can suppress generation | occurrence | production of the beep sound by this motor by using a load as a motor.

  Hereinafter, embodiments of the electrical apparatus of the present invention will be described in detail in the order of [Embodiment 1], [Embodiment 2], [Embodiment 3], [Embodiment 4], and [Embodiment 5] with reference to the drawings. explain. In the following description of embodiments, a small electric device such as an electric razor having a secondary battery and a load (motor) therein will be described as an example of the electric device.

[Example 1]
FIG. 1 is a configuration diagram of an electric apparatus according to an embodiment of the present invention. In the figure, the electric device of the present embodiment is a small electric device 50 that uses an output from an AC adapter 2 that includes a transformer that steps down the commercial power source 1 to a predetermined voltage. Turns on the drive of the secondary battery 7 as a drive power source, the switching element 3 that controls the supply of the AC adapter 2 output to the secondary battery 7 and the motor 8, the diode 4 that performs half-wave rectification, and the load (motor 8) A switch 9 for turning on / off, a control circuit 5 for performing on / off control of the switching element 3 at a frequency of 1 [kHz] or less which is not a multiple of the commercial power supply frequency, and a voltage detection circuit for detecting the voltage of the secondary battery 6 6 and a battery remaining capacity detection circuit 10 that detects the remaining capacity of the secondary battery 6.

  Here, the voltage detection circuit 6 is configured using a resistor, for example, and outputs a voltage generated by a voltage drop of the resistor to the control circuit 5 and the remaining battery capacity detection circuit 10 as a voltage detection signal.

  Further, the battery remaining capacity detection circuit 10 stores in advance the relationship between the battery voltage and the remaining capacity of the secondary battery 7 in the form of a table or as an arithmetic expression, and uses this to determine the remaining capacity of the secondary battery 7. The estimated remaining battery capacity is output to the control circuit 50.

  Note that the battery voltage generally has a characteristic that it becomes substantially linearly smaller as the discharge time becomes longer, and the battery voltage is affected by the battery temperature and becomes larger as the battery temperature becomes higher. 7 is provided, and the battery remaining capacity detecting circuit 10 includes a temperature detecting circuit (not shown) for detecting the temperature of the battery 7 and the relationship between the battery temperature and the battery voltage and the remaining capacity of the secondary battery 7 in a table format or as an arithmetic expression. The remaining capacity of the secondary battery 7 is stored based on the battery voltage detected by the voltage detection circuit 6 and the battery temperature indicated by the battery temperature information output from the temperature detection circuit. You may make it derive deduced.

  Next, the operation at the time of charging and driving the load (motor 8) of the small electrical apparatus 50 having the above configuration will be specifically described.

  When the AC adapter 2 is electrically connected to the commercial power source 1, the AC adapter 2 steps down the AC voltage of the commercial power source 1 to a predetermined voltage and supplies it to the small electrical device 50. When the small electric device 50 is charged, the switch 9 is in an off state, and the control circuit 5 switches the frequency to 1 [kHz] or less, which is not a multiple of the commercial power supply frequency, and a predetermined on-duty (switching in the driving cycle). On / off control of the switching element 3 is performed at a time ratio of turning on the element 3, and a predetermined current (according to the on-duty) is supplied to the secondary battery 7 via the diode 4, and the secondary battery 7 is charged.

  At the time of charging, the remaining battery capacity detection circuit 10 detects the remaining capacity of the secondary battery 6, and the control circuit 5 determines that the battery is fully charged based on the remaining battery capacity detected by the remaining battery capacity detection circuit 10. At that time, the switching element 3 is turned off to complete the charging of the secondary battery 6.

  Further, when the load (motor 8) of the small electrical device 50 is driven, the switch 9 is turned on, and the drive of the load (motor 8) and the charging of the secondary battery 6 are performed in parallel. At this time, the control circuit 5 turns on in the on / off control of the switching element 3 so that the battery voltage of the secondary battery 6 detected by the voltage detection circuit 6 becomes a predetermined voltage (for example, 2.6 [V]). Change the duty.

  That is, when the battery voltage is higher than the predetermined voltage, the on-duty is decreased, and conversely, when the battery voltage is lower than the predetermined voltage, the on-duty is increased, thereby keeping the battery voltage of the secondary battery 6 constant. Since the value obtained by subtracting the load current flowing to the load (motor 8) from the output current (of the diode 4) determined by the on-duty in the on / off control of the switching element 3 is the current supplied to the secondary battery 6, By changing the on-duty, the state of the secondary battery 6 can be changed to a charged state or a discharged state, and the battery voltage of the secondary battery 6 can be adjusted.

  As described above, the switching element 3 is on / off controlled by the control signal from the control circuit 5. FIG. 2A illustrates an on / off control signal of the switching element 3 in this embodiment. The frequency of on / off control of the switching element 3 is set to a frequency of 1 [kHz] or less which is not a multiple of the commercial power supply frequency (50 [Hz] / 60 [Hz]), and a frequency of about 170 [when the load (motor 8) is driven. Hz], and during charging, on / off control of the switching element 3 is performed at a frequency of about 91 [Hz].

  When a power transformer type AC adapter is used, it is known from experiments that when a load (motor) is driven at a drive frequency of 1 [kHz] or higher, a roar of motor sound cannot be heard. The load (motor 8) was driven at a frequency of [kHz] (see FIG. 2B). However, when the frequency is about 2 [kHz], the switching loss in the switching element 3 is large, the switching element easily generates heat, and it is necessary to use a switching element having a low on-resistance or a large rating, which increases the cost. It was connected to.

  Further, assuming that the frequency is 1 [kHz] or less and a multiple of the commercial power supply frequency (50 [Hz]), for example, 100 [Hz], as shown in FIG. 3, the output current from the AC adapter 2 (FIG. 3 (b) ))), The battery voltage (motor voltage) (see FIG. 3 (a)) fluctuates and a roaring sound is generated.

  Therefore, in the present invention, the load (motor 8) drive and the secondary battery 6 are set to, for example, 170 [Hz] which is not a multiple of the commercial power supply frequency (50 [Hz] / 60 [Hz]) when the frequency is 1 [kHz] or less. Is going to be charged. In this case, as shown in FIG. 4, the battery voltage (motor voltage) (FIG. 4 (a)) is not synchronized with the commercial power frequency (the fluctuation period of the output current from the AC adapter 2 (see FIG. 4 (b))). Because the voltage fluctuation of (see) is small, no roaring sound is generated.

  As described above, in the electrical apparatus according to the present embodiment, the output from the AC adapter 2 including the secondary battery 7 and the load (motor 8) and including the transformer that steps down the commercial power source to a predetermined voltage is used. Switching that controls charging of the secondary battery 7 and driving of the load (motor 8), and the control circuit 5 controls the supply of the AC adapter 2 to the secondary battery 7 and the load (motor 8). Since the on / off control of the element 3 is performed at a frequency of 1 [kHz] or less which is not a multiple of the commercial power supply frequency, the periodic voltage fluctuation of the battery voltage (motor voltage) is suppressed, and the generation of the beat sound Can be suppressed.

  In addition, since intermittent driving is performed at a switching frequency as low as 170 [Hz], for example, switching loss of the switching element 3 can be reduced and heat generation of the switching element 3 can be suppressed. The element 3 can be used, and the cost can be reduced. Furthermore, since the switching frequency is as low as 170 [Hz], for example, it is difficult to generate noise, and it is possible to reduce noise countermeasure components, thereby reducing costs.

[Example 2]
Next, an electrical apparatus according to Embodiment 2 of the present invention will be described. The electrical device according to the present embodiment is different from the small electrical device 50 according to the first embodiment in that the ON duty (switching element 3 is set to ON / OFF control of the switching element 3 by the control circuit 5 each time the battery voltage is detected by the voltage detection circuit 6. The time ratio of turning on is gradually changed.

  FIG. 5 exemplifies a change in on-duty in the on / off control of the switching element 3 when the battery voltage by the voltage detection circuit 6 is higher than a predetermined voltage (for example, 2.6 [V]). The switching frequency of the switching element 3 is 170 [Hz] as in the first embodiment, and the detection of the battery voltage by the voltage detection circuit 6 is, for example, about 0.7 [seconds] (that is, about 120 [drive cycle]). ) Every time.

  First, when the battery voltage detection value Vc1 is detected by the voltage detection circuit 6, the control circuit 5 sets an arbitrary on-duty (on time width Tc1) and starts on / off control of the switching element 3. Next, after about 0.7 [seconds] (about 120 [drive cycle]), when the voltage detection circuit 6 detects a battery voltage detection value Vc2 higher than a predetermined voltage (2.6 [V]), the control circuit 5 sets a smaller on-duty (on time width Tc2 <Tc1) to perform on / off control of the switching element 3. Thereafter, the on-duty is gradually reduced every time the voltage detection circuit 6 detects the battery voltage until the voltage detection circuit 6 decreases the battery voltage detection value to a predetermined voltage (2.6 [V]). The increment of the on-duty is, for example, that the switching frequency Ta (= 5.88 [msec]) of the switching element 3 is divided by 230, and the on-duty is changed by Ta / 230.

  FIG. 6 exemplifies a change in on-duty in the on / off control of the switching element 3 when the battery voltage by the voltage detection circuit 6 is lower than a predetermined voltage (2.6 [V]). Note that the switching frequency of the switching element 3 is 170 [Hz], and the battery voltage detection by the voltage detection circuit 6 is performed about every 0.7 [seconds].

  First, when the battery voltage detection value Vd1 is detected by the voltage detection circuit 6, the control circuit 5 sets an arbitrary on-duty (on time width Td1) and starts on / off control of the switching element 3. Next, after about 0.7 [seconds] (about 120 [drive cycle]), when the voltage detection circuit 6 detects a battery voltage detection value Vd2 lower than a predetermined voltage (2.6 [V]), the control circuit 5 sets a larger on-duty (on time width Td2> Td1) to perform on / off control of the switching element 3. Thereafter, the on-duty is gradually increased every time the battery voltage is detected by the voltage detection circuit 6 until the voltage detection value is increased to a predetermined voltage (2.6 [V]) by the voltage detection circuit 6. The increment of the on-duty change is, for example, Ta / 230.

  Even when the battery voltage fluctuates (increases or decreases) after the battery voltage of the secondary battery 6 reaches the predetermined voltage (2.6 [V]), the predetermined voltage (2.6 [V]) is again obtained. The on-duty is gradually changed until it reaches.

  As described above, in the electrical apparatus of this embodiment, the on-duty in the on / off control of the switching element 3 by the control circuit 5 is gradually changed every time the battery voltage is detected by the voltage detection circuit 6. It is possible to further suppress the generation of beat noise by further suppressing the voltage fluctuation range of (motor voltage).

Example 3
Next, an electrical apparatus according to Embodiment 3 of the present invention will be described. In the electric device of the present embodiment, in the small electric device 50 of the first or second embodiment, the initial setting of the on-duty when the control circuit 5 starts the on / off control of the switching element 3 is the voltage detection circuit 6. This is performed according to the battery voltage detection result of the secondary battery 6 according to the above.

  FIG. 7 illustrates an on-duty initial value of the switching element 3 according to the battery voltage VB of the secondary battery 6. When the battery voltage VB is considerably smaller than the predetermined voltage (2.6 [V]) (for example, the battery voltage VB ≦ 2.2 [V]), the on-duty is set as large as possible (100 [%]). Further, when the battery voltage VB is slightly smaller than the predetermined voltage (2.6 [V]) (for example, 2.2 [V] <battery voltage VB ≦ 2.55 [V]), the on-duty is relatively set. Is set to a large value (for example, 80 [%]), the on / off control of the switching element 3 is started so that the secondary battery 6 is charged.

  Conversely, when the battery voltage VB is slightly larger than the predetermined voltage (2.6 [V]) (for example, battery voltage VB> 2.65 [V]), the on-duty is set to a relatively small value (for example, 40 [%]), On / off control of the switching element 3 is started so that the secondary battery 6 is discharged.

  Further, when the battery voltage VB is approximately in the vicinity of the predetermined voltage (2.6 [V]) (for example, 2.55 [V] <battery voltage VB ≦ 2.65 [V]), it corresponds to the load current. On / off control of the switching element 3 is started with an on-duty (for example, 60 [%]). Here, the load current may be obtained by load current detection means (not shown in FIG. 1) for detecting the current flowing through the load (motor 8), or a rated value determined by the type of the load (motor 8) may be used. It may be used.

  The battery voltage of the secondary battery 7 varies depending on the use environment or the state of the battery. As described above, in the electrical apparatus of this embodiment, when the control circuit 5 starts the on / off control of the switching element 3. Since the initial setting of the on-duty is performed according to the battery voltage detection result of the secondary battery 6 by the voltage detection circuit 6, a predetermined voltage (eg, 2.6 [V ] As a result, the time zone in which the battery voltage fluctuates can be further shortened, and the generation of a roaring sound can be suppressed.

  In addition, the fact that the battery voltage of the secondary battery 6 reaches a predetermined voltage and is stably driven means that the supply current from the AC adapter 2 becomes equal to the load current, and the charge / discharge of the secondary battery 7 is eliminated. Since the stress on the secondary battery 6 is reduced, being able to reach a predetermined voltage in a short time also leads to a longer battery life of the secondary battery 6.

Example 4
Next, an electrical apparatus according to Embodiment 4 of the present invention will be described. In the electric device of this embodiment, in the small electric device 50 of the first embodiment or the second embodiment, the initial setting of the on-duty when the control circuit 5 starts the on / off control of the switching element 3 is used to detect the remaining battery capacity. This is performed according to the result of detecting the remaining battery capacity of the secondary battery 6 by the circuit 10.

  FIG. 8 illustrates an on-duty initial value of the switching element 3 according to the remaining battery capacity CAP of the secondary battery 6. When the remaining battery capacity CAP is considerably small (for example, when the remaining battery capacity CAP ≦ 25 [%]), the on-duty is set as large as possible (100 [%]), and the remaining battery capacity CAP is slightly more than half. When the amount is small (for example, 50 [%] <remaining battery capacity CAP ≦ 25 [%]), the on-duty control is started with the on-duty set to a relatively large value (for example, 70 [%]). Then, the secondary battery 6 is charged.

  Conversely, when the remaining battery capacity CAP is considerably larger than half (for example, remaining battery capacity CAP> 70 [%]), the on-duty is set to a relatively small value (for example, 35 [%]), and the switching element 3 On / off control is started, and the secondary battery 6 is discharged.

  Further, when the remaining battery capacity CAP is about half (for example, 70 [%] <remaining battery capacity CAP ≦ 50 [%]), the switching element is turned on with an on-duty (for example, 65 [%]) corresponding to the load current. 3 on / off control is started.

  Although the battery voltage of the secondary battery 7 varies depending on the remaining battery capacity, as described above, in the electrical apparatus of the present embodiment, the on-duty when the control circuit 5 starts the on / off control of the switching element 3. Is set in accordance with the result of detecting the remaining battery capacity of the secondary battery 6 by the remaining battery capacity detection circuit 10, so that a predetermined voltage (for example, 2.6 [V ] As a result, the time zone in which the battery voltage fluctuates can be further shortened, and the generation of a roaring sound can be suppressed.

  Similarly to the third embodiment, being able to reach the predetermined voltage in a short time also leads to a longer battery life of the secondary battery 6.

Example 5
Next, an electrical apparatus according to Embodiment 5 of the present invention will be described. The electric device of the present embodiment performs the battery voltage detection of the secondary battery 6 by the voltage detection circuit 6 at the timing immediately before the switching element 3 is turned on in the small electric device 50 of the first to fourth embodiments. is there.

  FIG. 9 is an explanatory diagram illustrating battery voltage fluctuations of the secondary battery 6 in the drive cycle of the load (motor 8). As shown in the figure, when the switching element 3 is turned on, an output is supplied from the AC adapter 2 and the secondary battery 7 is charged, so that the battery voltage of the secondary battery 6 rises. Thereafter, when the switching element 3 is turned off, the output from the AC adapter 2 is cut off, so that the battery voltage of the secondary battery 6 gradually decreases and stabilizes at a certain battery voltage.

  As described above, the battery voltage of the secondary battery 6 varies depending on the ON / OFF of the switching element 3, and the battery voltage of the secondary battery 6 varies depending on the timing detected by the voltage detection circuit 6 even within the same driving cycle. The precision of control in the small electrical device 50 of the first to fourth embodiments is lowered.

  Therefore, in the electrical apparatus of the present embodiment, since the battery voltage of the secondary battery 6 is most stable immediately before the switching element 3 is turned on, the battery voltage detection of the secondary battery 6 by the voltage detection circuit 6 is switched. The determination was made at the timing immediately before the element 3 was turned on. Thereby, the battery voltage detection accuracy of the secondary battery 6 by the voltage detection circuit 6 can be increased, and the charging control of the secondary battery 6 and the drive control of the load (motor 8) can be performed more stably.

It is a block diagram of the electric equipment which concerns on the Example of this invention. FIG. 2A is an explanatory diagram illustrating an on / off control signal of the switching element in the embodiment, and FIG. 2B is an explanatory diagram illustrating a conventional on / off control signal. It is explanatory drawing which illustrates the fluctuation | variation of the battery voltage (motor voltage) when a frequency is 100 [Hz]. It is explanatory drawing which illustrates the fluctuation | variation of the battery voltage (motor voltage) when a frequency is set to 170 [Hz]. It is explanatory drawing which illustrates the change of ON duty in ON / OFF control of a switching element when a battery voltage is higher than a predetermined voltage. It is explanatory drawing which illustrates the change of on-duty in on / off control of a switching element when a battery voltage is lower than a predetermined voltage. It is explanatory drawing which illustrates the on-duty initial value of the switching element according to the battery voltage of a secondary battery. It is explanatory drawing which illustrates the on-duty initial value of the switching element according to the battery remaining capacity of a secondary battery. It is explanatory drawing which illustrates the battery voltage fluctuation | variation of a secondary battery in the drive cycle of load (motor).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 AC adapter 3 Switching element 4 Diode 5 Control circuit 6 Voltage detection circuit 7 Secondary battery 8 Motor (load)
9 Switch 10 Battery remaining capacity detection circuit 50 Small electrical equipment

Claims (6)

An electric device comprising a secondary battery and a load, and using an output from an AC adapter having a transformer for stepping down a commercial power source to a predetermined voltage, charging the secondary battery and driving the load,
A switching element for controlling supply of the AC adapter output to the secondary battery and the load;
Control means for performing on / off control of the switching element at a frequency of 1 [kHz] or less which is not a multiple of the commercial power supply frequency;
Voltage detection means for detecting the voltage of the secondary battery,
The control means sets an initial value of the on-time of the switching element when starting on / off control of the switching element according to the voltage of the secondary battery detected by the voltage detecting means, and the voltage An electrical apparatus characterized by gradually varying the on-time in the control cycle of the switching element each time voltage is detected by the detecting means. The electrical apparatus according to claim 1, wherein the initial value of the on-time is set longer as the voltage of the secondary battery detected by the voltage detection unit is lower. 3. The electrical device according to claim 1, wherein the voltage detection unit detects the voltage of the secondary battery at a timing immediately before the switching element is turned on. An electric device comprising a secondary battery and a load, and using an output from an AC adapter having a transformer for stepping down a commercial power source to a predetermined voltage, charging the secondary battery and driving the load,
A switching element for controlling supply of the AC adapter output to the secondary battery and the load;
Control means for performing on / off control of the switching element at a frequency of 1 [kHz] or less which is not a multiple of the commercial power supply frequency;
Battery remaining capacity detection means for detecting the remaining capacity of the secondary battery ;
Voltage detection means for detecting the voltage of the secondary battery ,
The control means sets an initial value of the on-time of the switching element when starting the on / off control of the switching element according to the remaining capacity of the secondary battery detected by the battery remaining capacity detecting means. electrical apparatus, characterized in that to gradually vary the oN time of the control cycle of the switching element for each voltage detection by the voltage detecting means. The electrical apparatus according to claim 4, wherein the initial value of the on-time is set longer as the remaining battery capacity of the secondary battery detected by the remaining battery capacity detecting unit is smaller. The electric device according to claim 1, wherein the load is a motor.

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