JP3404996B2 - Power circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply circuit which rectifies a commercial power supply and drops the voltage to supply a predetermined DC voltage to a load section.

[0002]

2. Description of the Related Art A conventional power supply circuit generally has a structure as shown in FIG. The configuration will be described below.

The commercial power supply 1 supplies a voltage having a waveform as shown in FIG. The rectifying unit 2 is for unidirectionally flowing the current flowing through the circuit, and the rectifying unit 2 causes the voltage waveform of the commercial power supply to have a waveform as shown in FIG. Voltage drop unit 3
Reduces the output voltage of the rectifying unit 2 and limits the voltage applied to the load unit 4. The capacitor 5 normally stores electric charge, discharges while the voltage of the commercial power supply 1 is being cut by the rectification unit 2, and supplies the load unit 4 with the voltage having the waveform shown in FIG. 6.

[0004]

In such a conventional power supply circuit, since the voltage across the load section 4 is usually low, the voltage across the voltage drop section 3 is high, and the voltage supplied from the commercial power supply 1 is high. Since the voltage is divided only by the voltage drop unit 3 and the load unit 4, the voltage drop unit 3 has a problem that power consumption is large and heat generation is large.

[0005] The present invention is intended to solve the above problems, and reduce the power consumption of the voltage drop portion, and the purpose of suppressing the heat generation.

[0006]

The present invention SUMMARY OF] In order to achieve the above purpose, a commercial power source, a rectifier unit for rectifying the voltage of the commercial power supply, a voltage drop portion that drops the output voltage of the rectification part And a third rectifier connected in series with this voltage drop unit
Parts, capacitors, a first rectifier unit and the load unit, the con
Connected to both ends of the series connection of the capacitor and the first rectifying section.
A transistor, a series of the first rectifying unit and the load unit
A second rectifying section connected to both ends of the connection;
Equipped with a control circuit that controls the rectifier and transistor
The control circuit supplies power to the rectification unit from the commercial power source.
Together when the flow is flowing is connected in series to the load section to said condenser, so as to store charges in the capacitor
When no current flows through the rectifying unit, the load unit is connected in parallel with the capacitor, and the current flows through the rectifying unit.
The electric charge stored in the capacitor when
The first to third rectifying units and the rectifying unit for driving the load unit.
Configured to control the transistor , and more
Specifically, the control circuit causes the rectification unit to be connected to the commercial power source.
When current flows from the source, open the transistor
The capacitor and the load section are not connected in series, and the
If no current flows through the flow section, short-circuit the transistor
To connect the capacitor and the load in parallel
The above-mentioned configuration is a means for solving the problem.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention by challenge solutions described above, the one-way supply energy from a commercial power source of positive or negative polarity of the commercial power supply, the action of the third rectifier unit and the first rectifying portion
The load part is connected in series with the capacitor, and the capacitor is charged through the series circuit of the commercial power source, the rectifying part, the voltage drop part, and the load part, and the voltage is dropped by the capacitor.

With another polarity of the commercial power source, the load current is connected to the capacitor in parallel by turning on the transistor by the discharge current of the capacitor, and the charge stored in the capacitor is discharged to the load part connected in parallel to the capacitor. Therefore, the load can be operated by this discharge current. Therefore, the voltage is divided by the capacitor and dropped.
Therefore, the current flowing through the voltage drop unit is small and the drop voltage is also small, so that the power consumption of the voltage drop unit can be suppressed to be small.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The same components as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. As shown in the figure, the capacitor 6 is connected to the voltage drop unit 3 in series, and the load unit 4 is connected to the capacitor 6 via the switch unit 7 in series.

The switch section 7 includes a capacitor 6 and a load section 4.
And a transistor 9 connected in parallel to the series circuit of the capacitor 6 and the first rectification unit 8, and a parallel circuit connected to the series circuit of the first rectification unit 8 and the load unit 4. And the second rectifying unit 10 connected to the commercial power source 1, the transistor 9 is turned off and the load unit 4 is connected in series with the capacitor 6 in the direction in which the polarity of the commercial power source 1 is the current i1.
In the case where the polarity is opposite to the direction in which the current i1 flows, the transistor 9 is turned on by the discharge current of the capacitor 6, and the load unit 4 is connected in parallel to the capacitor 6.

The discharge current blocking unit 11 blocks the charge of the capacitor 6 from discharging to the commercial power source 1 in the opposite direction of the polarity of the commercial power source 1 from which the current i1 flows.
The rectifying section 12 and the fourth rectifying section 13 are connected to the voltage drop section 3 and the capacitor 6 in series. In addition, 14
Is a current limiting resistor.

To explain the operation in the above configuration, when the polarity of the commercial power supply 1 is in the direction in which the current i1 flows, the transistor 9 is off, the load section 4 is connected in series to the capacitor 6, and the capacitor 6 is connected to the commercial power supply 1. Charging is performed through a series circuit of the rectification unit 2, the voltage drop unit 3, and the load unit 4. At this time, the voltage of the commercial power supply 1 can be divided into the voltage drop unit 3, the capacitor 6, and the load unit 4, and the voltage across the voltage drop unit 3 can be reduced.

Next, when the polarity of the commercial power supply 1 is opposite to the direction in which the current i1 flows, the transistor 9 is turned on by the discharge current of the capacitor 6, and the series circuit of the transistor 9, the load section 4, and the second rectifying section 10 is provided. Are connected in parallel to the capacitor 6, and the discharge current of the capacitor 6 can operate the load unit 4. At this time, the first rectifying unit 8 can prevent the capacitor 6 from being short-circuited by the transistor 9.

Therefore, the polarity of the commercial power source 1 is the current i1.
In the direction opposite to the direction in which the current flows, the load unit 4 is connected in parallel to the capacitor 6, and the charge charged in this capacitor 6 is transferred to the load unit 4
Can be discharged, and the load part 4 can be operated by this discharge current. Therefore, since the current flowing through the voltage drop unit 3 is small and the drop voltage is also small, the voltage drop unit 3
It is possible to reduce the power consumption of.

Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in the figure, the switch section 15 includes a first rectifying section 16 connected between the capacitor 6 and the load section 4.
A transistor 17 connected in parallel to the series circuit of the capacitor 6 and the first rectification unit 16, and a second rectification unit 18 connected in parallel to the series circuit of the first rectification unit 16 and the load unit 4. However, when the polarity of the commercial power source 1 is the direction in which the current i1 flows, the transistor 17 is turned off and the load unit 4 is connected in series to the capacitor 6, and when the polarity of the commercial power source 1 is in the direction opposite to the direction in which the current i1 flows, the capacitor is The transistor 17 is turned on by the discharge current of 6, and the load unit 4 is connected to the capacitor 6 in parallel.

The discharge current blocking unit 19 blocks the charge of the capacitor 6 from discharging to the commercial power source 1 in the direction opposite to the direction in which the current i1 flows in the polarity of the commercial power source 1.
The rectifying section 20 and the fourth rectifying section 21 are connected to the voltage drop section 3 and the capacitor 6 in series.

To explain the operation in the above configuration, when the polarity of the commercial power supply 1 is in the direction in which the current i1 flows, the transistor 17 is off, the load section 4 is connected in series to the capacitor 6, and the capacitor 6 is connected to the commercial power supply 1, Charging is performed through a series circuit of the rectification unit 2, the voltage drop unit 3, and the load unit 4. At this time,
The voltage of the commercial power supply 1 can be divided into the voltage drop unit 3, the capacitor 6, and the load unit 4, and the voltage across the voltage drop unit 3 can be reduced.

Next, when the polarity of the commercial power supply 1 is opposite to the direction in which the current i1 flows, the transistor 17 is turned on by the discharge current of the capacitor 6, and the second rectifying unit 18, the load unit 4, and the series circuit of the transistor 17 are connected. Are connected in parallel to the capacitor 6, and the discharge current of the capacitor 6 can operate the load unit 4. At this time, the first rectifying unit 16
Thus, the capacitor 6 can be prevented from being short-circuited by the transistor 17.

Therefore, the polarity of the commercial power supply 1 is the current i1.
In the direction opposite to the direction in which the current flows, the load unit 4 is connected in parallel to the capacitor 6, and the charge charged in this capacitor 6 is transferred to the load unit 4
Can be discharged, and the load part 4 can be operated by this discharge current. Therefore, since the current flowing through the voltage drop unit 3 is small and the drop voltage is also small, the voltage drop unit 3
It is possible to reduce the power consumption of.

[0021]

As described above, according to the present invention, the commercial power source, the rectifying section for rectifying the voltage of the commercial power source, the voltage dropping section for dropping the output voltage of the rectifying section, and the voltage dropping section in series. Connected third rectifier, capacitor , first rectifier and
And a load unit, the capacitor and the first rectifying unit in series
A transistor connected to both ends of the connection, and the first rectifier
Rectification connected to both ends of the series connection of the load section and the load section
Part, and the first to third rectifying parts and the transistor.
And a control circuit for controlling the rectification unit .
As well as connected in series with said <br/> capacitor the load unit when the current flows from the commercial power source, the capacitor
So that no electric current flows through the rectifier.
When it is connected in parallel to the load section to said condenser, before
When the current flows through the rectifier, it is stored in the capacitor.
To drive the load unit with the stored electric charge.
Configured to control the third rectifier and the transistor
And because, in the one-way supply energy from a commercial power source of positive or negative polarity of the commercial power source, the third rectifier unit and the first
The load section connected in series with the capacitor by the action of the rectifying section, the voltage can be lowered to a capacitor with charges the capacitor, the other polarity of the commercial power supply, that transistor is turned on by the discharge current of the capacitor < The load part is connected in parallel to the capacitor, the charge of this capacitor can be discharged to the load part, the load part can be operated by this discharge current, and the capacitor can be charged.
Since the voltage is divided and dropped, the current flowing through the voltage drop unit is small and the dropped voltage is also small, so that the power consumption of the voltage drop unit can be suppressed to a low level.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a power supply circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a power supply circuit according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a configuration of a conventional power supply circuit.

FIG. 4 is a voltage waveform diagram of a commercial power supply of the same power supply circuit.

FIG. 5 is a waveform diagram of the output voltage of the rectifying unit of the power supply circuit.

FIG. 6 is a waveform diagram of the output voltage of the capacitor of the same power supply circuit.

[Explanation of symbols]

1 Commercial Power Source 2 Rectifier 3 Voltage Dropper 4 Load 6 Capacitor 7 Switch 8 First Rectifier 9 Transistor 10 Second Rectifier 12 Third Rectifier

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-244772 (JP, A) JP-A-1-284003 (JP, A) JP-A-6-38521 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H02M 7/21

Claims (2)

(57) [Claims] 1. A commercial power source, a rectifying unit that rectifies the voltage of the commercial power source, a voltage drop unit that drops the output voltage of the rectifier unit, and a third rectifier connected in series to the voltage drop unit.
Parts, capacitors, a first rectifier unit and the load unit, the con
Connected to both ends of the series connection of the capacitor and the first rectifying section.
A transistor, a series of the first rectifying unit and the load unit
A second rectifying section connected to both ends of the connection;
Equipped with a control circuit that controls the rectifier and transistor
The control circuit supplies power to the rectification unit from the commercial power source.
Together when the flow is flowing is connected in series to the load section to said condenser, so as to store charges in the capacitor
When no current flows through the rectifying unit, the load unit is connected in parallel with the capacitor, and the current flows through the rectifying unit.
The electric charge stored in the capacitor when
The first to third rectifying units and the rectifying unit for driving the load unit.
A power supply circuit configured to control a transistor . 2. A commercial power source and the voltage of this commercial power source are rectified
And the voltage drop that drops the output voltage of this rectifier.
Lower part and third rectifier connected in series with this voltage drop part
Section, a capacitor, a first rectifying section and a load section, and
Connected to both ends of the series connection of the capacitor and the first rectifying section.
A transistor, a series of the first rectifying unit and the load unit
A second rectifying section connected to both ends of the connection;
Equipped with a control circuit that controls the rectifier and transistor
The control circuit supplies power to the rectification unit from the commercial power source.
When a current flows, the transistor is opened and the
Connect the capacitor and the load section in series, and connect the rectifier section with electricity.
If no current flows, short the transistor and
A structure that operates so that the capacitor and the load section are connected in parallel.
And power supply circuit.