JPH11285273A - Power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit for comb-shaped terminal voltage which changes periodically. SOLUTION: This power supply unit is provided with a first diode 51 for applying a chopper inductor 2 voltage to a first capacitor 41 during the off- period of a chopper switching element 3, and a second diode 52 for applying the chopper inductor 2 voltage to a second capacitor 42 during the off-period of the chopper switching element 3. During the on-period of the chopper switching element 3, the first capacitor 41 and the second capacitor 42 are connected in series to each other via the chopper switching element 3, and both their voltages are added to be applied to an output terminal 6. During the off-period of the chopper switching element 3, the first capacitor 41 voltage is applied via the second diode, and the second capacitor 42 voltage is applied via the first diode 51, to the output terminal 6 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chopper-operated power supply, and more particularly to a power supply of a type whose output voltage changes.

[0002]

2. Description of the Related Art A DC power supply, a chopper inductor, a chopper switching element for intermittently applying the DC power voltage to the chopper inductor, a capacitor, and an off period of the chopper switching element are provided. A power supply device having a diode for applying the chopper inductor voltage to the capacitor is well known and widely used.

[0003]

The conventional power supply device outputs a uniform DC voltage. The output terminal voltage cannot be changed periodically. An object of the present invention is to provide a power supply device having a comb-shaped output terminal voltage whose output voltage changes periodically.

[0004]

SUMMARY OF THE INVENTION The present invention comprises a DC power supply. A chopper inductor is provided. A chopper switching element for intermittently applying the DC power supply voltage to the chopper inductor. A first capacitor and a second capacitor are provided. A first diode for applying the chopper inductor voltage to the first capacitor during an off period of the chopper switching element.
A second diode for applying the chopper inductor voltage to the second capacitor during an off period of the chopper switching element. The arrangement of the first capacitor, the second capacitor, the first diode, the second diode,
The capacitors and diodes are defined to form a closed circuit that alternates. During the ON period of the chopper switching element, the first capacitor and the second capacitor are connected in series via the chopper switching element, and the voltages of both are added and applied to the output terminal. During the off period of the chopper switching element, the first capacitor voltage is applied to the output terminal via the second diode, and the second capacitor voltage is applied to the output terminal via the first diode. 2 for the former
In the latter case, the output terminal voltage becomes a double output terminal voltage. Switch it back alternately. The output terminal voltage has a comb-like waveform alternately including a single-type and a double-type.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The power supply of the present invention includes a DC power supply 1. The term “power supply device” is a general term for the entire circuit device including the DC power supply 1. A chopper inductor 2 is provided. A chopper switching element 3 for intermittently applying a DC power supply 1 voltage to a chopper inductor 2 is provided. A first capacitor 41 and a second capacitor 42 are provided. A first diode 51 is provided for applying the voltage of the chopper inductor 2 to the first capacitor 41 during the off period of the chopper switching element 3. During the off period of the chopper switching element 3, the voltage of the chopper inductor 2 is applied to the second capacitor 42.
And a second diode 52 for applying a voltage to the second diode. The arrangement of the first capacitor 41, the second capacitor 42, the first diode 51, and the second diode 52 is determined so as to form a closed circuit in which the capacitors and diodes alternate. The closed circuit must not be a closed circuit of the first capacitor 41, the second capacitor 42, the second diode 52, the first diode 51, and the first capacitor 41. DC power supply 1 is AC power supply 11
It is a rectifying power supply of a type for rectifying a voltage, and includes rectifying diodes 12 to 15 forming a full-wave rectifying circuit. Electromagnetic energy is stored in the chopper inductor 2 during the ON period of the chopper switching element 3. During the off period of the chopper switching element 3, a rightward voltage is formed in the chopper inductor 2. The chopper inductor 2 voltage is applied to the first capacitor 41 via the first diode 51 and to the second capacitor 42 via the second diode 52, respectively, to charge the first capacitor 41 and the second capacitor 42. By such chopper operation, each capacitor 4
A desired voltage is formed on the power supply 1 and the high power factor of the DC power supply (rectified power supply) 1 is maintained. During the ON period of the chopper switching element 3, the first capacitor 41 and the second capacitor 42 have a forward-series relationship via the chopper switching element 3, and a double-type voltage obtained by adding both voltages is output to the output terminal 6. Form. During the off period of the chopper switching element 3, the voltage of the first capacitor 41
2 and the voltage of the second capacitor 42 are applied to the output terminal 6 via the first diode 51, respectively. During the on-period of the chopper switching element 3, the voltage becomes a double output terminal 6 voltage, and during the off-period, it becomes a single output terminal 6 voltage. Repeat it alternately. Thereby, the output terminal 6
The voltage has a comb waveform. FIG. 2 shows the power supply device 10 shown in FIG.
0 is an application example. The inverter 200 is connected to the output terminal 6 of the power supply device 100. The inverter 200 includes a pair of in-series inverter switching elements 201 and 202 connected to the output terminal 6, and includes another similar in-series pair of inverter switching elements 203 and 204.
Flywheel diodes 211 to 214 connected in antiparallel to switching elements 201 to 204 for inverters
Is included. 220 is an inverter switching element 2
This is an inverter load connected between the connection point 01/202 and the connection point of the inverter switching elements 203/204. A control circuit 150 turns on and off the chopper switching elements 3 belonging to the power supply device 100 and the inverter switching elements 201 to 204 belonging to the inverter 200 as needed. FIG. 3 shows an output terminal voltage V6 formed at the output terminal 6 of FIG. 2 and an inverter load voltage V220 formed at both ends of the inverter load 220.
It is a waveform of. 2 and 3, the output terminal voltage V
6 turns off (turns on) the inverter switching elements 201 and 204 at the midpoint of the period in which the 6 exhibits the low-level 1-time type (the off period of the chopper switching element 3), and switches the inverter switching elements 202 and 22.2.
03 is turned on (turned off). Therefore, the inverter load voltage V220 has a ternary level waveform as shown in FIG. The inverter 20 of FIG.
Numeral 0 is an ordinary simple non-ternary level general-purpose inverter. Nevertheless, the whole of FIG. 2 including the power supply device 100 functions as a well-known ternary level type inverter (neutral point clamp type inverter). The application circuit diagram of FIG. 4 will be described. The parts numbers in FIG. 2 are used as is in FIG. 4 as much as possible, and a part of the overlapping description is omitted as appropriate. 4 is a discharge lamp lighting circuit including a discharge lamp 221 and a ballast inductor 222 in series therewith. The inverter load voltage V220 in FIG. 4 is as shown in FIG. 4 and 5, the output terminal voltage V6
Rises from a low-level single-type to a high-level double-type at the timing when the inverter switching element 201.
204 is turned off (turned on), and the inverter switching elements 202 and 203 are turned on (turned off). Therefore, the inverter load voltage V220
Is as shown in FIG. Each half-wave voltage of the inverter load voltage V220 has a pre-high-low waveform including the double voltage first and the single voltage after. The re-ignition when the discharge lamp 221 current is commutated is performed under a high level double voltage, and after the re-ignition, the ignition is continued under the single voltage.
According to this, the possibility of re-ignition failure is low, and there is no fear that an excessive tube current peak value is formed after re-ignition.

[0006]

According to the present invention, a DC power supply, an inductor for a chopper, a switching element for a chopper, a first capacitor, a second capacitor, a first diode, and a second diode are connected as described above. According to this, it is possible to easily obtain a comb-shaped output terminal voltage in which the single and double times are repeated.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of the device of the present invention.

FIG. 2 is an application circuit diagram of FIG.

FIG. 3 is a voltage waveform diagram of FIG.

FIG. 4 is another application circuit diagram of FIG. 1;

FIG. 5 is a voltage waveform diagram of FIG.

[Explanation of symbols]

 1: DC power supply 2: Chopper inductor 3: Chopper switching element 41: First capacitor 42: Second capacitor 51: First diode 52: Second diode

Claims (1)

[Claims] A chopper switching element (3) comprising a DC power supply (1), comprising a chopper inductor (2), and intermittently applying a voltage of said DC power supply (1) to said chopper inductor (2). And the first capacitor (4
1) and a second capacitor (42), and converts the voltage of the chopper inductor (2) to the first capacitor (41) during an off period of the chopper switching element (3).
A first diode (51) for applying a voltage to the second capacitor (42) during an off period of the chopper switching element (3).
A second diode (52) applied to the first capacitor (41) and the second capacitor (42).
-The power supply device characterized in that the arrangement of the first diode (51) and the second diode (52) is determined so as to form a closed circuit in which the capacitors and the diodes alternate.