JP2604303B2 - High frequency constant current power supply method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency constant-current power supply system for supplying power from a high-frequency constant-current power supply to a load using a current transformer.

[0002]

2. Description of the Related Art Conventionally, a commercial power supply and other power supplies are usually of a constant voltage type, but depending on the type of load, a constant current type is sometimes more convenient. For example, in the case of a fluorescent lamp load, it is extremely difficult to adjust the discharge voltage to adjust the dimming because of the negative resistance characteristic.However, it is quite easy to adjust the dimming by adjusting the discharge current. In order to perform stable control, a constant current type power supply is more rational than a constant voltage type power supply. In the case of incandescent lamps, the filament has a low resistance before lighting and has a steady state resistance when it becomes hot after energization. This causes a large amount of fatigue when the filament is turned on. However, if the filament is turned on by a constant current type power supply, no excessive current flows when the filament is turned on, so that the life can be significantly extended.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency constant-current power supply system for supplying power from a high-frequency constant-current power supply to a load using a current transformer.

[0004]

To achieve the above object, a high-frequency constant-current power supply system according to the present invention comprises a high-frequency constant-current power supply, an iron core having a primary winding and a secondary winding, respectively. And a load connected to the secondary winding of each current transformer, and the primary windings of all current transformers are connected in series to the high-frequency constant current power supply. . Further, it is characterized in that the means for adjusting the magnetic resistance of the iron core adjusts the effective sectional area or the magnetic gap of the iron core by moving a movable part provided in a part of the iron core. Further, the high-frequency constant-current power supply includes means for adjusting the value of the output current.

[0005]

[Operation] The operation in the case of a fluorescent lamp load will be described.
Before the fluorescent lamp starts discharging, the current transformer saturates and almost no current flows through its secondary winding, but after the discharge starts, it is determined by the current flowing through the primary winding of the current transformer and the winding ratio. The discharge current flows through the fluorescent lamp, and the terminal voltage of the secondary winding is reduced to a discharge voltage corresponding to the discharge current of the fluorescent lamp and stabilized. Since the current transformer has a means for adjusting the magnetic resistance of the iron core, the value of the current flowing through the secondary winding can be adjusted, and the dimming of the fluorescent lamp connected to the current transformer can be performed without any loss. It can be performed stably. Further, it is possible to perform dimming of all the connected fluorescent lamps by adjusting the current value by the current adjusting means provided in the high-frequency constant current power supply. Furthermore, if the magnetic resistance of the current transformer is adjusted to be infinite, the current flowing through the secondary winding becomes zero, so that the power supplied to the load connected to the current transformer can be cut off. The means for adjusting the resistance can have a function as a switch.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. Commercial power supply 1
A plurality of current transformers 4a, 4b,
All the primary windings 4c, 4d,... Are connected in series. The secondary windings of the current transformers 4a, 4b, 4c have fluorescent lamps 5a, 5b, 5c respectively provided with starting capacitors Ca, Cb, Cc, and the secondary winding of the current transformer 4d has an incandescent lamp. 5d is connected as a load. A fluorescent lamp, an incandescent lamp, a motor, a heater, and other loads are also connected to a current transformer (not shown).

The output of the inverter 2 is f = 65 kHz,
It is a high frequency constant current of I ₀ = 10A. The current transformer is
A primary winding and a secondary winding are wound around an annular iron core made of ferrite having good high-frequency characteristics and having a cross-sectional area of 1 cm ² . The number of turns of the primary winding of the current transformer 4a is 2 turns, the number of turns of the secondary winding is 36 turns, the fluorescent lamp 5a has a commercially available rating of 110W, and the capacitor Ca = 0.0.
023 μF. The primary windings of the current transformers 4b and 4c are one turn just penetrating the conducting wire 3, the number of turns of the secondary winding is 24 turns, the fluorescent lamps 5b and 5c are rated 40 W, and the capacitors Cb and Cc = 0.0023 μF. The current transformer 4d is a combination of two E-shaped cores, the primary winding of which is one turn around the conductor 3 around the core, the number of turns of the secondary winding is 10 turns, and the incandescent lamp 5d is rated at 100V. , 100W.

The current transformers 4c and 4d have means for adjusting the magnetic resistance of the iron core. As shown in FIG. 2, the iron core of the current transformer 4c is composed of a U-shaped main body portion 6 and a movable portion 7 rotatably supported by the main body portion. By moving, the effective magnetic area of the contact portion can be adjusted to adjust the overall magnetic resistance. As shown in FIG. 3, the iron core of the current transformer 4d adjusts the magnetic resistance by adjusting the magnetic gap by rotating the two E-shaped cores 8 with the hinges 9. .

The operation when the fluorescent lamp is turned on will be described with reference to the fluorescent lamp 5a.
There before starting the discharge, the secondary winding of the current transformer _{4a Ia = I 0 × n 1} / n 2 = 10 × 2/36 = 0.55A
Flows through the capacitor Ca to heat the heater of the fluorescent lamp 5a. Since the impedance of the capacitor Ca at f = 65 kHz is 520 Ω, a voltage of 290 V is applied between the heaters of the fluorescent lamp 5 a at this time, and the process proceeds to the hot cathode discharge in a short time.
From the characteristic of a, stable lighting is performed in a state where the discharge voltage has decreased to 180 V corresponding to a discharge current of 0.55 A.

From the beginning, a current of Id = 1 A flowing through the secondary winding of the current transformer 4d flows through the filament of the incandescent lamp 5d. However, while the resistance value of the filament is low at first, the filament lights up darkly and the filament is gradually heated. As the resistance value increases, the brightness increases and the current becomes 0.2 to 0.
After 5 seconds, it will be in a steady state.

After the fluorescent lamp 5c is stably turned on, the current transformer 4
When the movable portion 7c is rotated in a horizontal plane as shown in FIG. 2, the effective cross-sectional area of this portion of the iron core decreases, and the magnetic resistance of the entire iron core increases. The value of the current flowing through the next winding can be reduced. That is, the movable part 7
The dimming of the fluorescent lamp 5c can be performed by adjusting the rotation angle of the fluorescent lamp 5c. Similarly, the dimming of the incandescent lamp 5d can be performed by rotating the E-shaped core 8 of the current transformer 4d up and down to change its magnetic gap. If the inverter 2 is provided with means for adjusting the value of the output current, the power supplied to all loads can be adjusted uniformly.

Note that the frequency of the output current of the inverter 2 is not limited to the value of the above embodiment, but may be 1 to 15
It can be appropriately selected within a wide range of about 0 kHz,
If the frequency is 0 kHz or less, audible frequency noise may be generated, and if the frequency is 30 to 37 kHz, a remote control such as a television may malfunction, so the frequency is preferably 40 kHz or more. Further, the design of the current value of the output current, the shape and dimensions of the current transformer, the shape of the movable portion, the number of turns of the primary and secondary windings, the number of loads, and the like can be appropriately changed as necessary.

[0013]

As described above, the high-frequency constant-current power supply system according to the present invention can supply power to various loads. In comparison, the operation can be controlled extremely stably, and there is no need to provide a lighting ballast or lighting inverter for each fluorescent lamp, so that the size of the apparatus can be reduced. Since no abnormal voltage is generated, the life of fluorescent lamps and incandescent lamps can be remarkably prolonged. In addition, the provision of means for adjusting the magnetic resistance of the iron core eliminates the need to adjust the power supplied to individual loads. It can be performed very easily with loss, and if the high-frequency constant-current power supply is provided with a means for adjusting the output current, the effect of uniformly controlling the power supplied to all loads can be obtained. To.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of one of the current transformers.

FIG. 3 is a perspective view of another current transformer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Inverter 3 Conductor 4a, 4b, 4c, 4d Current transformer 5a, 5
b, 5c Fluorescent lamp 5d Incandescent lamp 6 Main body 7 Moving part 8 E-shaped core 9 Hinge

Claims (4)

(57) [Claims] 1. A high-frequency constant-current power supply, and a plurality of current transformers each having a primary winding and a secondary winding and having a means for adjusting a magnetic resistance of an iron core. A high-frequency constant-current power supply system, wherein a load is connected to a line and primary windings of all current transformers are connected in series to the high-frequency constant-current power supply. 2. The method according to claim 1, wherein the means for adjusting the magnetic resistance of the iron core adjusts the effective sectional area of the iron core by moving a movable part provided on a part of the iron core. Item 2. A high-frequency constant current power supply system according to Item 1. 3. A method according to claim 2, wherein the means for adjusting the magnetic resistance of the iron core adjusts the magnetic gap of the iron core by moving a movable part provided on a part of the iron core. 2. The high-frequency constant current power supply system according to 1. 4. The high-frequency constant-current power supply system according to claim 1, wherein the high-frequency constant-current power supply includes means for adjusting the value of the output current.