JPH0629915Y2 - Lighting lamp energization control circuit - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention relates to a current control circuit for a lighting lamp, and in particular,
The present invention relates to a lighting lamp energization control circuit suitable for preventing a rush current into a filament of a lamp when energizing the lamp.

(B) Conventional technology As a conventional lighting lamp energization control circuit, for example,
The one shown in Fig. 4 was provided.

In the figure, 1 is a power supply section, 2 is a power switch, 3 is a load section other than the lamp display section, 4 is a dimming circuit, 4a is a dimming resistor, 4b and 4c are transistors, 5 is a lamp, and 6 is dimming. The switch 7 is a lamp protection resistor.

As for the circuit configuration, the power supply unit 1 is connected to the load unit 3 via the power supply switch 2, and is also connected to the dimming circuit 4 via the lamp protection resistor 8 and the dimming switch 6.

The circuit configuration of the dimming circuit 4 is such that the dimming resistor 10 is connected to the lamp protecting resistor 8 so that the lamp 5 is provided on the output side of the dimming circuit 4.
It is connected to the.

The power supply voltage input via the dimming switch 6 is applied to the base of the transistor 11, and the collector is connected to the base of the transistor 9.

The emitter and collector of the transistor 9 are resistors for dimming
10 are connected in parallel at both ends.

As for the control operation of the lamp 5, when the power switch 2 is turned on and the dimming switch 6 is in the off state, the transistors 4b and 4c of the dimming circuit 4 are in the cutoff state, so the lamp protection resistor 7 and the dimming A current flows through the lamp 5 through the resistor 4a for lighting the lamp 5 in a dimmed state.

Further, when the power switch 2 is turned on when the dimming switch 6 is on, the power supply voltage is applied to the base of the transistor 4c via the dimming switch 6, so that the transistors 4c and 4b are turned on. The resistor 4a for light is short-circuited and the lamp 5 is turned on in a normal energized state.

However, when the dimming switch 6 is in the ON state, the dimming resistor 4a is short-circuited at the same time when the power switch 2 is turned on. Therefore, as shown in the lamp current characteristic diagram at the start of energization in FIG. Immediately after turning on, inrush current flows.

(C) Problems to be solved by the invention However, in the above-mentioned conventional lighting lamp energization control circuit, the dimming switch 6 is in the on state as shown in FIGS. In this state, since the same voltage as that during energization is applied to the lamp 5 even when energization is started, there is a drawback that the filament inrush current of the lamp 5 is very large and filament breakage easily occurs. Also,
There is a drawback that the life of the lamp is shortened even if the wire is not broken.

This invention has been made in view of the above-mentioned points, and the purpose thereof is to eliminate the drawbacks of the conventional example, to make the same amount of current as when dimming at the beginning of lamp energization, and then to normal energization state. The present invention provides a lighting lamp energization control circuit.

(D) Means for Solving the Problems The lighting lamp energization control circuit according to the present invention is a lighting lamp energization control circuit for displaying the operation of an electronic device including a dimming circuit, and turns on or off the dimming circuit. A timer circuit is provided in series with the dimming switch to operate the voltage at the start of energizing the lamp as the voltage at dimming when the dimming switch is turned off.

(E) Operation According to the present invention, in the energization control circuit of the lighting lamp for displaying the operation of the electronic device having the dimming circuit, the timer circuit is provided in series with the dimming switch for turning on and off the dimming circuit, Since the voltage at the start of energization to is operated as the voltage at the time of dimming with the dimming switch turned off, the same voltage as the current at the time of dimming is applied to the filament of the lamp at the start of energization, Inrush current is prevented and the life of the lamp is extended.

(F) Embodiment An embodiment of the energization control circuit for the illumination lamp according to the present invention will be described with reference to FIGS. 1 to 3.

The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a circuit configuration diagram of the present invention, FIG. 2 is a characteristic diagram of a lamp current at the time of dimming, and FIG. 3 is a characteristic diagram of a lamp current at a normal energization.

In the figure, 7 is a timer circuit.

As for the circuit configuration, the power supply voltage supplied via the power switch 2 is directly connected to the dimming resistor 4a of the dimming circuit 4, and further connected to the dimming switch 6 from the dimming switch 6. It is added to the base of transistor 4c via timer 7.

The circuit operation immediately after the power switch 2 is turned on will be described assuming that the dimming switch 6 is on. The power supply voltage supplied via the power switch 2 is passed through the dimming switch 6 to the timer circuit 7 and the dimming circuit. The timer circuit 7 operates so as to be turned on with a delay of about 100 ms after the voltage is applied.

Therefore, the transistors 4b and 4c of the dimming circuit 4 are not turned on during the delay period of the timer circuit 7 and the dimming resistor 4a.
Therefore, a current in a dimmed state will flow through the lamp 5 since it is not short-circuited.

When the timer circuit 7 is turned on after a predetermined delay period, it is added to the base of the transistor 4c of the dimming circuit 4 through the dimming switch 6 to turn on the transistor 4c of the dimming circuit 4 and turn on the transistor 4b. As a result, the dimming resistor 4a is short-circuited to bring it into a normal energized state.

By operating the circuits in the above-described order, the current to the lamp 5 at the start of energization is the current at the time of dimming and then becomes the normal energizing current, so that the inrush current is prevented from flowing to the lamp 5. It will be.

In addition, when the above-mentioned state is reached and the normal lamp is turned on, when the dimming switch 6 is turned off to dimm the light source voltage is not added to the timer circuit 7, and is also added to the base of the transistor 4c of the dimming circuit 4. Transistor because it disappears
Since 4b is cut off and the dimming resistor 4a is not short-circuited, a current flows through the dimming resistor 4a and the lamp 5 is dimmed.

It should be noted that the timer circuit 7 is adapted to maintain the ON state even after the power supply voltage from the dimming switch 6 is cut off after the delay period has passed.

The timer circuit 7 can also be controlled by a microcomputer.

Furthermore, a rush current can be further reduced by inserting a resistor between the power switch 2 and the dimming resistor 4a.

(G) Effect of the Invention According to the energization control circuit of the lighting lamp according to the present invention,
In the lighting lamp energization control circuit that displays the operation of electronic devices equipped with a dimming circuit, a timer circuit is provided in series with a dimming switch that turns the dimming circuit on and off, and the voltage at the start of energizing the lamp is dimmed. Since the switch is turned off to operate as the voltage at the time of dimming, the inrush current at the start of energization can be prevented and the life of the lamp can be extended.

Further, since the lamp protection resistor is unnecessary, the illuminance of the lamp can be increased.

Furthermore, since the lamp protection resistor needs to have a large heat loss and has a large shape, the cost can be reduced and the device can be miniaturized by deleting the resistor.

Moreover, it has excellent features such as a simple structure and easy implementation because it can be constructed at low cost.

[Brief description of drawings]

1 to 3 show an embodiment of a lighting lamp energization control circuit according to the present invention. FIG. 1 is a circuit configuration diagram, FIG. 2 is a lamp current characteristic diagram when the lamp is dimmed, and FIG. It is a lamp current characteristic view at the time of a normal energization state. 4 and 5 show a conventional example, FIG. 4 is a circuit configuration diagram, and FIG. 5 is a lamp current characteristic diagram in a normal energized state. Explanation of main symbols 1: Power supply part 2: Power supply switch 3: Load part 4: Dimming circuit 4a: Dimming resistance 4b, 4c: Transistor 5: Lamp 6: Dimming switch 7: Timer circuit

Claims (1)

[Scope of utility model registration request] 1. A lighting lamp energization control circuit for displaying an operation of an electronic device having a dimming circuit, wherein a timer circuit is provided in series with a dimming switch for turning on and off the dimming circuit to start energizing the lamp. A lighting lamp energization control circuit, characterized in that it is configured to operate as a voltage at the time of dimming by turning off the dimming switch.