JPH0332326A - Power supply circuit for both chargeable apparatus and ac apparatus - Google Patents

Abstract

PURPOSE:To eliminate abrupt variation of output current and to supply stable power, in a power source for charging a battery and driving a load, by providing a means for detecting load drive voltage and an output control means for varying output current from the power supply continuously. CONSTITUTION:Upon throw in of AC voltage V1, a switching transistor Q1 functions to induce AC pulse voltage in the secondary winding of a transformer T. The induced voltage is rectified through a diode D1 and fed, as an output current Iout, to a battery B. When a switch Sw is turned ON, another motor to be charged by the battery is also driven. When the battery voltage VB exceeds over a predetermined level VB1, a transistor Q2 is turned ON to reduce the voltage to be induced in the transformer winding L1 in an oscillation base circuit and thereby output Iout from a switching power supply decreases gradually to go to zero when the battery voltage reaches to VB2. Since the output lout does not go to zero instantaneously even if the battery voltage exceeds over the predetermined level VB1, motor drive voltage V2 does not fluctuate abruptly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply circuit for a charging/AC dual-use device that is driven by a battery power source or an AC power source and is equipped with a load such as a motor.

[Conventional technology]

BACKGROUND OF THE INVENTION Conventionally, among charging and AC dual-use devices that have a built-in storage battery and drive a load using the battery power source or an AC power source, devices that charge the storage battery while driving the load using the AC power source are known. In other words, when a load is driven with an AC power supply connected, the load and storage battery are connected between the output terminals of the power supply circuit, and the storage battery is charged by the difference between the output current from the power supply circuit and the drive current of the load. It is designed so that In such a configuration, a problem arises in that voltage fluctuations in the storage battery due to charging cause, for example, fluctuations in the driving voltage of the motor, which in turn causes fluctuations in the number of revolutions. Therefore, in the power supply circuit of conventional charging AC dual-use equipment, the battery voltage is kept at a constant voltage El.
When the battery voltage rises to a certain voltage El, the current supply from the power supply circuit is stopped and the motor is driven by the storage battery, and when the battery voltage drops to a certain voltage El due to discharge, the current supply from the power supply circuit is started again. This attempts to suppress fluctuations in the motor drive voltage. In this case, in order to stably control the output current of the power supply circuit, the above [problem to be solved by the invention] By the way, in the power supply circuit of the conventional charging AC dual-use device, the battery voltage is lower than the voltage El. Or, when the voltage reaches El, the output current from the power supply circuit changes suddenly between a constant current value and O, so fluctuations in battery voltage and motor load occur due to delays in turning on and off the output current. Alternatively, due to the above-mentioned hysteresis for stable output current control, the driving voltage of the motor may suddenly change temporarily, causing uneven rotation of the motor or a whining noise.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a power supply circuit for a charging AC dual-use device that can eliminate sudden fluctuations in the output current of the power supply circuit and provide a stable power supply.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a power supply circuit for a charging AC device that supplies an output current to charge a storage battery and drive a load. and output control means for continuously changing the output current according to fluctuations in the detected voltage.

Further, in the power supply circuit of the charging/AC dual use device, the power supply circuit is composed of a switching power supply having a switching element that oscillates in response to a control signal, and the power supply circuit is rectified by applying the output of the output control means to the control signal. This is designed to stop the switching operation that switches the voltage. Furthermore, the power supply circuit comprises a switching power supply having a switching element that is turned on and off by a pulse signal, and the output control means continuously changes the pulse width of the pulse signal in accordance with fluctuations in the detected voltage. It is.

[Effect]

In the power supply circuit of the charging/AC dual-use device configured as described above, the voltage detection means detects the drive voltage applied to the load, and inputs the detected voltage to the output control means of the power supply. When the drive voltage fluctuates due to fluctuations in battery voltage, the output control means continuously changes the output current of the power supply circuit in accordance with the fluctuation, thereby preventing sudden fluctuations in power supply to the load.

Further, in the power supply circuit, a switching element performs a predetermined switching operation in response to a control signal, and outputs a predetermined blade pattern flow. The output of the output control means is applied to the control signal in response to variations in the drive voltage of the load, thereby changing the switching operation. As a result, the output current of the switching power supply changes continuously in accordance with fluctuations in the drive voltage of the load.

Further, the power supply circuit uses a switching element to stop the switching operation of the switching element during the rectification period. As a result, the stop period of the switching operation changes in accordance with fluctuations in the drive voltage of the load, and the output current changes continuously.

Further, in the power supply circuit, a switching element performs a switching operation based on a pulse signal, and outputs a predetermined output current. The output control means continuously changes the pulse width of the pulse signal according to the drive voltage of the load. As a result, the output current changes continuously according to the drive voltage of the load.

(Example) FIG. 1 shows a circuit configuration diagram of a power supply circuit of a charging AC dual-use device according to the present invention. The basic configuration of the power supply circuit 1 shown in the figure is a self-excited DC-D (I) inverter type switching power supply. In the figure, the series circuit of the primary winding under the transformer and the switching transistor Q1 is the rectifier A storage battery B is connected to the secondary winding under the transformer via a diode 1). Further, a series circuit consisting of a resistor R3 and a resistor R4 and a septa motor M are connected in parallel to the storage reservoir 13 via a drive switch 8w for the motor M. Further, an oscillation base circuit consisting of a resistor R2, a capacitor C1 transformer winding "1" and a diode 12 is connected between the base and emitter of the switching transistor Q1, and the output terminal (positive side) of the rectifying element RE F is connected to the output terminal (positive side) of the rectifying element REF. Anno-1 of diode D2
A resistor R1 for starting oscillation is connected between the two. Further, a helang resistor Q2 (which controls the oscillation level of the oscillation base circuit) is connected in parallel to both ends of the capacitor C1. The connection point between the resistor R3 and the resistor R4 is connected to the bases of the transistors Q1 to Q2, and the motor M
A divided voltage V3 obtained by dividing the drive type IBV2 is inputted.

With the above circuit configuration, when AC voltage vl is applied, a base current flows to the switching transistor Q+ via the starting resistor R1, and the switching transistor Q1 is connected to the capacitor C1 of the oscillation base circuit and the Herance winding [1]. The switching operation is started at a predetermined frequency determined by a time constant of -1. Due to the switching operation of the switching transistor Q1, the rectified voltage of the rectifying element R', which is printed on the primary winding under the transformer, becomes a pulsed AC voltage, and the secondary winding side under the transformer receives a pulsed AC voltage. A voltage is induced.The alternating current generated by this pulsed alternating voltage is rectified by diode 1 and supplied to storage battery B as output current 10UT of the switching power supply, thereby charging storage battery B.

When the switch SW is closed (hereinafter referred to as "turned on"), the output current IoUT is supplied to the storage battery B and the motor M, so that the storage battery B is charged and the Tanabata motor M is driven.

Then, as the storage battery B is charged, the battery voltage VB
gradually rises, and along with this, the drive of motor M! ! ! I voltage V2 (=-battery voltage VB) also rises. However, if the above battery type "VB exceeds a predetermined voltage VBl,
By turning off the single transistor Q2, the voltage induced in the transformer winding 11 of the oscillating single switch circuit is reduced. As a result, the output of the switching power supply';t
i? 7it I ou T will decrease.

Then, when the battery voltage VB reaches the voltage VB2, the output current 10UT of the switching power supply becomes zero. , that is, the oscillation of switching 1 to transistor Q1 completely stops.

Figure 2 shows the above-mentioned battery voltage VB and output current 10 tJ.
It is a figure showing the relationship with T. As shown in the opening/closing diagram, when the motor M is moved by the AC power supply, the battery voltage VB is set to the predetermined voltage V.
If B+α is below, a constant output current is is supplied to the storage battery 8 and the motor M from the switching power supply. When the battery voltage Vn exceeds the predetermined pressure VEl, the output current l0UT
decreases linearly according to the battery voltage VB, and the voltage VB2
becomes 0. In this way, the battery voltage VB is set to the predetermined voltage VBl.
Even if the output current exceeds 10 UT, the output current does not become O instantaneously, and the motor M dynamic voltage V2 does not change suddenly, so there is no possibility of uneven rotation or whining of the motor M. .

Next, a second embodiment will be described in which it is determined whether the battery voltage VB exceeds a predetermined voltage VBl by comparing the divided voltage V3 with a predetermined voltage V4, which will be described later, to control the on/off operation of the transistor Q2. . Figure 3 is the second
1 shows a circuit configuration diagram of an example. In this figure, members having the same functions as those in FIG. 1 are given the same reference numerals.

In the figure, the Nancho circuit consisting of resistors R5 and R6 connected between the output terminals of the rectifier RFP is a circuit that divides the rectified voltage, and the divided voltage V4 is input to the inverting input terminal of the comparator OP. There is.

Further, the divided voltage V3 is input to the non-inverting input terminal of the comparator OP, and the output terminal of the comparator OP is connected to the base of the transistor Q2. Thereby, the comparator OP compares the divided voltage V4 and the divided voltage Vs, and controls the on/off operation of the transistor Q2.

The operation of this embodiment will be explained using FIG. 4. In the same figure, (a) is the divided voltage V input to the comparator OP.
s and the waveform of the divided voltage V4, (b) shows the waveform of the voltage v5 output from the comparator OP, and (C) shows the voltage waveform applied to the primary winding of the transformer T. When the divided voltage Vs exceeds the divided voltage V4, the output voltage Vs of the comparator OP becomes high level, and the transistor Q2 is turned on. As a result, the voltage between the base and emitter of the switching transistor Q1 becomes O, so that oscillation is stopped. If the divided voltage v3 when starting the motor drive by the AC power supply is V31 in FIG. 4(a), then the comparator OP
The output waveform of is P31, and the primary winding voltage of the transformer T has a waveform that oscillates for a period T31 of each rectified waveform, as shown in FIG. 4(C). After that, when the battery voltage VB of storage battery B rises by 1 and the divided voltage v3 rises to V32, the comparator OP
The output waveform becomes P32, and the oscillation period of the primary winding voltage of the transformer T decreases from period T31 to period Ta2, thereby decreasing the output current fouT.

Then, when the divided voltage v3 exceeds the peak value of the divided voltage V4 (V3 > V4), the oscillation of the switching transistor Q1 completely stops, and the output current 1ou'r becomes 0. That is, as shown in FIG. 2, the output current 10UT gradually decreases as the battery voltage VB increases.

Next, a third embodiment using a separately excited switching power supply will be described. FIG. 5 shows the circuit configuration of the third embodiment. In this figure, members having the same functions as those in FIG. 1 are given the same reference numerals.

Reference numeral 1 denotes an oscillation circuit provided independently within the power supply, which controls the switching operation of the switching transistor Q1. Reference numeral 2 denotes an oscillation control circuit for controlling the pulse duty of the oscillation output of the oscillation circuit 1, and the pulse duty of the oscillation output of the oscillation circuit 1 is controlled by the driving voltage 2 of the motor M.

This embodiment will be explained using FIG. 6. FIG. 6 shows the output waveform of the oscillation circuit 1.

In the figure, the switching transistor Q1 is turned on during the period TON, and turned off during the period TOFF. When driving a motor using an AC power source, the battery voltage V
When B increases and exceeds the voltage vBl, the oscillation control circuit 2 shortens the width of the period TON to reduce the pulse duty in accordance with the rise in the battery voltage VB, and when the battery voltage VB reaches the voltage VB2, the oscillation control circuit 2 Set the width of TON to 0. As a result, the output current 10UT is the battery voltage VB71% voltage VB
It decreases as the voltage VB1 increases, and the battery voltage VB becomes the voltage VB.
When it reaches 2, it becomes O.

Next, a fourth embodiment using a separately excited type switching power supply will be described. FIG. 7 shows the circuit configuration of the fourth embodiment. This figure shows that in the circuit configuration of FIG. 5, the battery voltage Vs is inputted manually to the intermittent oscillation circuit 3 instead of being inputted to the oscillation control circuit 2, and the output of the intermittent oscillation circuit 3 is used as the base of Ql via the switching transistor 3. It is connected. The intermittent oscillation circuit 3 is configured such that the output impedance changes as follows depending on the input voltage.

That is, the output impedance becomes a high resistance state until the battery voltage VB reaches the voltage VBl, and the voltage VB2 (VB2 >
VB+) or more, the output impedance becomes a low resistance state, and when VB1≦VB<VB2, the output impedance repeats a high/low resistance state period T1 and a low resistance state period T2 as shown in FIG. The configuration is such that the period T1 of the high and low resistance state becomes shorter as the resistance increases.

The operation of this embodiment will be explained. In this example, the sixth
The period T'ON and the period TOFF of the output signal of the oscillation circuit 1 shown in the figure are fixed. When the AC power supply is turned on and the switch SW is off, that is, when the battery voltage Va is not input, the output impedance of the intermittent oscillation circuit 3 is in a high resistance state, and the switching operation of the switching transistor Q1 is as shown in FIG. The output current 1OUT is a constant value Is.
It becomes 4. Next, when the switch 8w is turned on, the battery voltage VB is input to the intermittent oscillation circuit 3. If the battery voltage VB is equal to or lower than the predetermined voltage V131, the intermittent oscillation circuit 3
The output impedance of is still in a high resistance state.

However, when the battery voltage VE increases by 1 and exceeds the predetermined voltage VBl, the output impedance repeats a high resistance state and a low resistance state as shown in FIG. 8 according to the battery voltage VE.
, l, become angry. When the output impedance of the intermittent oscillation circuit 3 becomes a low resistance state, the base potential of the switching 1 to transistor Q1 drops to the ground level, so during the period T2 of the low resistance state, the switching 1 to transistor Q
The switching operation of No. 1 will be stopped. As a result, the output current 1out when VB2≧VB>VBl is L
From the period T-1, T2 and -.constant voltage 1 s, 10UT=T1.Is/(T+→-T2).

Moreover, since the period 1 becomes shorter as the battery voltage VB increases, the output current rouT decreases as the battery voltage VB increases. Then, when the battery voltage VB or voltage VB2 is reached, T+=0 and the output current 1OUT becomes ○.

(Effects of the Invention) As explained above, according to the present invention, when the battery voltage rises above a predetermined voltage when driving a motor using an AC power source, the output current of the power supply circuit is gradually reduced in accordance with the rise in the battery voltage. As a result, sudden fluctuations in the drive voltage applied to the motor are eliminated, uneven rotation of the motor and generation of whining noise can be prevented, and smooth rotational drive of the motor can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the circuit configuration of the power supply circuit of the charging AC dual-use device according to the present invention, FIG. 2 is a diagram showing the relationship between the battery voltage and output current of the power supply circuit, and FIG. 3 is a diagram showing the second embodiment. 4(a), (b), and (c) are time charts for explaining the circuit operation of the second embodiment. FIG. 5 is a diagram showing the circuit of the third embodiment. , FIG. 6 is a diagram showing the output waveform of the oscillation circuit, FIG. 7 is a diagram showing the circuit configuration of the fourth cusp embodiment, and FIG. 8 is a diagram showing the change in output impedance of the intermittent oscillation circuit. DESCRIPTION OF SYMBOLS 1...Oscillation circuit, 2...Oscillation control circuit, 3...Intermittent oscillation circuit, R1-R6...Resistor, C1...'Nden 1no, Shi1...1~France line, B...Storage battery,
D+, D2...Diode, M...Motor, O
P...Comparator, Q1Q2...1~Ran resistor, RE
F... Rectifier, SW... Switch, T... Transformer.

Claims (1)

[Scope of Claims] 1. In a power supply circuit of a charging AC device that supplies an output current to charge a storage battery and drive a load, means for detecting the drive voltage of the load and responding to fluctuations in the detected voltage. and output control means for continuously changing the output current. 2. The power supply circuit comprises a switching power supply having a switching element that oscillates in response to a control signal, and the output current is controlled by applying the output of the output control means to the control signal. Item 1
Power supply circuit for the charging AC dual-use device described. 3. The power supply circuit comprises a switching power supply having a switching element for switching a rectified voltage, and is characterized in that the operation of the switching element is stopped during a period when the drive divided voltage of the load is equal to or higher than the rectified divided voltage. A power supply circuit for a charging AC dual-use device according to claim 1. 4. The power supply circuit consists of a switching power supply having a switching element that is turned on and off by a pulse signal, and the output control means is configured to continuously change the pulse width of the pulse signal in accordance with fluctuations in the detected voltage. The power supply circuit for a charging/AC dual-use device according to claim 1.