JPH05146154A - Ac input automatic changeover device - Google Patents

Abstract

PURPOSE:To provide an AC input automatic changeover device for an industrial sewing machine which changes over input so that the DC output may be constant at all times by automatically judging the AC input voltage of single-phase 100V or three-phase 200V. CONSTITUTION:When the voltage of single-phase 100V is input, a voltage detecting circuit 15 does not operate, and the first, second, and third relays RY1, RY2, and RY3 of an automatic changeover circuit 16 operate after a time t1, whereby the contact 13 of a power source circuit is turn on, and the voltage inputted to a motor driving circuit 10 doubles. Moreover, a fourth relay RY4 operates after a time t2, whereby the rush current can be limited. When three-phase 200V is input, a voltage detecting circuit operates, and the first, second, and fourth relays of the automatic changeover circuit stop operation, and a motor 11 can be driven with double voltage, and also the third relay RY3 operates after a time t3, and the rush current can be limited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC input automatic switching device for automatically discriminating a single-phase 100v or three-phase 200v AC input voltage and switching the input so that the DC output voltage becomes constant.

[0002]

2. Description of the Related Art Generally, as a device which shares 100V and 200V inputs, a device in which terminals of a switching board are manually replaced is known, and as automatic switching, a battery charging circuit for a VTR or the like is used. In, single phase 1
When 00v is input, the internal circuit is automatically made a voltage doubler rectifier circuit to generate DC280v, and when single phase 220v is input,
A device is known in which an internal circuit is automatically a full-wave rectification circuit to obtain DC310v, and a stable low voltage (for example, DC8v) required for battery charging is obtained by a DC-DC converter circuit having DC280v to DC310v inputs.

[0003]

As described above, in the switching substrate which is manually replaced, a person judges the voltage.
There is a risk of damaging the device by accidentally inserting 200v into a 100v electrical component, and also requires work for switching, and in industrial sewing machines, automatic switching devices are not yet known.

[0004]

The present invention is directed to a first AC.
In a switching device provided with a conversion device for converting a DC voltage applied to a motor into a predetermined value in response to an input of a voltage or a second AC voltage, the conversion device is provided with the first AC voltage or the second AC voltage. The voltage detection device that operates according to the above is provided.

[0005]

According to the present invention, when a 100V single-phase voltage is input, the output voltage of the power supply rectification circuit applied from the power supply rectification circuit to the motor drive circuit and the detection rectification circuit applied from the detection rectification circuit to the detection circuit. The output voltage has a potential of 140v.

At this time, the voltage division ratio of the two base resistors of the transistor is set so that the transistor of the voltage detection circuit does not turn on.

On the other hand, since the transformer input switching section on the primary side of the transformer is selected to be AC200v (two windings in series), the voltage on the secondary side of the transformer is halved to 24v.
The output potential of the regulator is about 14v.

The first transistor is turned on and the first and second relays are turned on after a delay of a time constant (t1) determined by three resistors and a capacitor of the automatic switching circuit.

When the first and second relays of the automatic switching circuit are turned on, the contacts of the transformer input switching section are switched, and the input of the transformer becomes AC100v (two windings are in parallel). Therefore, the output voltage of the transformer is changed. Is the specified value,
The 24v regulator provides a stable voltage of 24v.

At this time, the rating of the first relay is exceeded, but at the same time, the contact connected in parallel with the resistor connected in series to the first relay is switched, and the first relay is connected to the first relay in series. A divided voltage is applied to the resistor connected to (the resistor is determined so that the voltage across the first relay is + 12v).

Further, by turning on the second relay,
The contact of the power supply rectifier circuit is turned on, whereby the power supply rectifier circuit becomes a voltage doubler rectifier circuit, and the motor drive circuit becomes a three-phase 20
It is 280v, which is the same as at 0v.

When AC200v is input, a voltage of DC280v is applied to the voltage detection circuit, but when the voltage division ratio of the two base resistors of the transistors of the detection circuit is a certain value or more (for example, 200v), the transistor is turned on. If the light emitting diode of the photocoupler emits light and the phototransistor turns on, the first and second relays become inoperative.

As a result, the input of the transformer is AC200v.
The power supply rectifier circuit remains as the three-phase full-wave rectifier, and the motor drive circuit is the same as when the AC100v is input.
It is a constant value at C280v.

[0014]

FIG. 1 is a circuit diagram of an AC input automatic switching device for an industrial sewing machine according to one embodiment of the present invention.
In phase 200v, the number of input power supplies is different and single phase 1
At 00v, it is possible to separately
AC input cord terminals 1 and 2 are prepared and single phase 100v AC
Input code terminal 2 has A between No.2 and No.3 pins.
Input C voltage.

A power switch 4 and a fuse 5 are connected to the three cord terminals 3 corresponding to the AC input cords 1 and 2, and a contact composed of a resistor and a contact is connected to the fuse 5 and the terminals a and b of the power rectifier circuit 6. Smoothing circuits 8 and 9 having capacitors and resistors and a motor driving circuit 10 are connected in parallel via a circuit 7, a motor 11 is connected to the motor driving circuit 10, and a connecting portion of the parallel circuits 8 and 9 is connected. A contact circuit 12 and a contact 13, which are parallel circuits of a resistor and a contact, are connected between the terminal c and an intermediate terminal c of the power rectifier circuit 6.

A detection rectification circuit 14 is connected to the power supply rectification circuit 6, and a contact S1 is connected to a terminal d on the input side of the detection rectification circuit 14.

Further, a voltage detection circuit 15 is connected to the detection rectification circuit 14, and this voltage detection circuit 15 has a capacitor C1 and resistors R1 and R2 between a terminal e of the detection rectification circuit 14 and a terminal b of the power supply rectification circuit 6. Connected in series, the base of the transistor T1 is connected to the connection point of the resistors R1 and R2, the emitter is connected to the terminal b, and the collector is connected to the terminal d via the light emitting diode PD of the photocoupler PH and the resistor R3. Has been done.

Further, a phototransistor PT of the automatic switching section 16 is provided so as to face the light emitting diode D1 of the photocoupler PH, and the collector of the phototransistor PT is connected to the terminal f via the terminal f and the resistor R4.
The emitter is connected to the terminal h.

Further, resistors R5 and R6 are connected in series between the terminals f and h, the base of the first transistor T2 is connected to the connection point of the resistors R5 and R6, and the base and the terminal h. The capacitor C2 is connected and the emitter is also the terminal h.
Further, the collector is connected to the terminal g through the first relay RY1 and the resistor R7.

A diode D1 and a switch S2 are connected to both ends of the first relay RY1 and a resistor R7, and the switch S2 and the diode D1 are connected in series.

A parallel circuit of a second relay RY2 and a diode D2 is connected between the collector of the first transistor T2 and the terminal g.

Further, a resistor R8 is provided between the terminals g and h.
R9 is connected, the base of the second transistor T3 is connected to the connection point of the resistors R8 and R9, the capacitor C3 is connected between this base and the terminal h, the emitter is connected to the terminal h, and the collector is It is connected to the collector of the transistor T2 via the diode D3, one end of a parallel circuit of the third relay RY3 and the diode D4 is connected, and the other end of the parallel circuit is connected to the terminal g.

Further, resistors R10 and R11 are provided between the terminals g and h.
Connected in series, and the base of the third transistor T4 is connected to the connection point of these resistors R10 and R11.
A capacitor C4 is connected between this base and the terminal h,
Further, the emitter of the third transistor T4 is connected to the terminal h, the collector is connected to one end of the parallel circuit of the fourth relay RY4 and the diode D5, and the other end of the parallel circuit is connected to the terminal g.

Further, the cord terminal 3 No. 2 and No. 3 is connected to a transformer input switching unit 17 having contacts S3 and S4, and the transformer input switching unit 17 has a transformer 18
The primary side of is connected.

A switching power supply rectifier circuit 19 is connected to the secondary side of the transformer 18, one end of this solenoid rectifier circuit 19 is connected to a terminal h, and a capacitor C5 and a 24v regulator 20 are connected between the other terminal j and the terminal h. 24v
The output terminal of the regulator 20 is connected to the terminals g and h.

The operation of this embodiment will be described below with reference to the time chart of FIG. 2. First, the contacts S1, S2, S3, S4 of the first relay RY1, the contact 13 of the relay RY2 and the contact circuit 7 of the relay RY3. The contact S5 is in the state shown in the figure when the power is off.

At this time, the switch 4 is turned on to turn on 100v.
When the single-phase voltage is input, the terminal a of the power rectifier circuit 6
A potential of 140v is generated as the output voltage between the terminals b, but the voltage division ratio of the resistors R1 and R2 connected to the base of the transistor T1 is set so that the transistor T1 of the voltage detection circuit 15 does not turn on.

On the other hand, the contacts S3 and S4 of the transformer input switching section 17 connected to the primary side of the transformer 18 are AC20.
Since 0v (two windings in series) is selected, the voltage on the secondary side of the transformer 18 is also halved, and the output potential of the 24v regulator 20 is about 14v.

Here, the resistance R4 of the automatic switching circuit 16,
The first transistor T2 is turned on after a delay of a time constant (t1) determined by R5, R6 and the capacitor C2, and the first, second,
The third relays RY1, RY2 and RY3 are turned on.

The first relay RY1 of the automatic switching circuit 16
Is turned on, the contacts S3 and S4 of the transformer input switching unit 17 are switched, and the input of the transformer 18 is AC.
Since the output voltage of the transformer 18 is 100 V (two windings are in parallel), the output voltage of the transformer 18 is a specified value,
It is a stable voltage of 4v.

At this time, the first relay RY1 exceeds the rating, but at the same time, the contact S2 connected in parallel to the resistor R7 connected in series to the first relay RY1 is turned off, and the first relay RY1 is turned off. Is applied with a divided voltage with a resistor R7 connected in series to the first relay RY1 (this resistor R7 has a voltage across the first relay RY18 of + 12v).
Has been decided to be).

Further, when the second relay RY2 is turned on, the contact 13 connected to the power supply rectifier circuit 6 is turned on, whereby the power supply rectifier circuit 6 becomes a voltage doubler rectifier circuit, and the motor drive circuit 10 has three phases. 280 same as 200v
Then, the motor 11 is driven.

Further, as shown in FIG. 3, AC is connected to the input terminal 3.
When 200 V is input, DC28 is applied to the voltage detection circuit 15.
Although the potential of 0v is applied, when the voltage division ratio of the two base resistors R1 and R2 of the transistor T1 of the voltage detection circuit 15 is a certain value or more (for example, 200v) or more, the transistor T1
Is set to turn on, the photo coupler P
The H light emitting diode PD emits light and the phototransistor PT is turned on, so that the first and second relays RY
1 and RY2 are inoperative.

As a result, the input of the transformer 18 is AC20.
The power supply rectification circuit 6 remains the three-phase full-wave rectification, and the motor drive circuit 10 has a constant value of DC280v like the AC100v input transformer.

In the above embodiment, as shown in FIG. 4, when the first and second relays RY1 and RY2 are turned on, the third relay RY3 is also turned on and the contact S5 of the power supply circuit 7 is turned on. When turned on, the resistor R12 is cut, but the fourth relay RY4 is not turned on, so the contact S5 of the contact circuit 12 is off, and therefore the smoothing circuit 8, through the resistor R13 of the contact circuit 12, Since the current flows through the capacitors C5 and C6 of No. 9, the inrush current is limited.

Then, the resistor R1 of the automatic switching circuit 16
0, R11 and time determined by capacitor C5 (t
2) Later, the transistor T4 is turned on, whereby the contact 6 of the contact circuit 12 is turned on and bypasses the resistor R13, but this time (t2 is the time for which the capacitors C7, C8 of the smoothing circuits 8, 9 are sufficiently charged). Inrush current will be limited.

Further, as shown in FIG. 5, in the three-phase 200v, since the photocoupler PH is turned on, the transistor T is turned on.
2, T4 is turned off, and the first to fourth relays RY1,
RY2, RY3, RY4 are off, transformer input is AC
At 200v, the power supply rectifier circuit 6 remains full-wave rectified.

Here, only the transistor T3 is a relay R.
After a time (t3) determined by the combined resistance of Y1 and RY2, the resistances R8 and R9, and the capacitor C3, the third relay RY3 is turned on and the contact S5 of the contact circuit 7 is turned on.

If the capacitors C6 and C7 of the smoothing circuits 8 and 9 are sufficiently charged within this time (t3), the rush current is limited by the resistor R12.

[0040]

As described above, the AC input automatic switching device of the present invention automatically determines the AC input voltage,
Since the output is made constant based on the result, damage due to operation does not occur due to manual switching, and the inrush current at switching is reduced to prevent the resistor from generating heat during operation. In addition, there is an advantage that the output becomes constant even if the AC input voltage is switched from the single phase to the three phases, or conversely from the three phases to the single phase.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an AC input automatic switching device for an industrial sewing machine according to an embodiment of the present invention.

FIG. 2 is a time chart explaining the operation when a single phase 100v is input in the circuit of FIG.

FIG. 3 is a time chart explaining the operation when three-phase 200v is input in the circuit of FIG.

4 is a time chart explaining an operation of limiting an inrush current when a single phase 100v is input in the circuit of FIG.

5 is a time chart for explaining an operation of limiting an inrush current when three-phase 200v is input in the circuit of FIG.

[Explanation of symbols]

 1, 2 AC input code 3 Code terminal 4 Power switch 5 Fuse 6 Power supply rectification circuit 7 Contact circuit 8, 9 Smoothing circuit 10 Motor drive circuit 11 Motor 12 Contact circuit 13 Contact 14 Detection rectification circuit 15 Voltage detection circuit 16 Automatic switching unit 17 Transformer input switching unit 18 Transformer 19 Switching power supply rectifier circuit 20 24v regulator

Claims (4)

[Claims] 1. A switching device provided with a converter for converting a DC voltage applied to a motor into a predetermined value in response to an input of a first AC voltage or a second AC voltage, wherein the converter has the first AC input automatic switching device, characterized in that a voltage detection device that operates according to the AC voltage or the second AC voltage is provided. 2. The AC according to claim 1, further comprising an automatic switching circuit unit connected to a relay that opens and closes a contact provided in the conversion device according to a signal from the voltage detection device.
Automatic input switching device. 3. The AC according to claim 1, wherein when a first AC voltage or a second AC voltage is applied, a relay contact of the conversion device is operated by a signal from the voltage detection device. Automatic input switching device. 4. The AC input automatic switching device according to claim 1, wherein the first AC voltage and the second AC voltage are single-phase 100v and three-phase 200v, respectively.