JPH03233895A - Device for lighting up discharge lamp - Google Patents

Abstract

PURPOSE:To reduce unnecessary power loss in a voltage lowering resistance by using part or whole of the current of a resistance load applied during the discharge period of a smoothing condenser for maintaining the current flowing through an on-angle control circuit as the power for the control circuit. CONSTITUTION:To prevent a phase control dimmer 2 from functioning incorrectly, a load resistance 4 is turned on and off at the timing of a waveform (b) including the output voltage waveform V1 (waveform a) of a full wave rectifier 3 and a short overlap time Ta. The timing of the waveform (b) is formed in a control circuit 14 based on the waveform V1 divided with resistances 8 and 9. A signal for driving a transistor 6 is outputted via a resistance 5, a transistor 7, a diode 10, and a resistance 11. Applying the current flowing through the load resistance 4 directly to the power source of the control circuit 14, the current flowing through the load resistance 4 is effectively utilized, and accordingly the currents flowing through resistances 16 and 17 may be reduced. As a result, unnecessary electric power loss is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge lamp lighting device that can be used in a phase control dimmer for a light bulb.

[Conventional technology]

As a circuit for generating direct current (pulsating current) from an AC power supply having a conduction angle control circuit, there is a circuit using a conduction control circuit connected in parallel to the load as described in Japanese Utility Model Application Publication No. 60-32797. Further, there are devices in which the conduction angle control circuit is connected in series to the load.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account the power source of a control circuit for controlling the opening and closing of a switching element, etc. for short-circuiting the output of a rectifier with a resistive load.

For example, when a commercial AC power source is used as an input to a rectifier, if a resistor is used to step down the voltage generated at the output of the rectifier to create a low-voltage control circuit power source, the power loss in the resistor increases.

An object of the present invention is to solve the above-mentioned problems and reduce unnecessary power loss in the step-down resistor.

[Means to solve the problem]

The above object is achieved by using part or all of the current flowing through the resistive load during the discharging period of the smoothing capacitor as a power source for the control circuit in order to maintain the current flowing through the conduction angle control circuit.

[Effect]

A current flows through the resistor in synchronization with the input AC power supply, and this is stored in a capacitor and voltage clamped by a Zener diode to be used as a control circuit power supply.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In Fig. 1, l is an AC power supply, 2 is a phase control dimmer, and 3 is a phase control dimmer.
is a full-wave rectifier, 4 is a load resistor, 5 is a bias resistor for transistor 6, 7 is a drive transistor for transistor 6,
8 and 9 are resistors, 10 is a diode, and 11 is a base resistance of transistor 7.

12 is a capacitor, 13 is a Zener diode.

14 is a control circuit, 15 and 20 to 22 are diodes,
16 and 17 are resistors, 18 and 19 are smoothing capacitors, 23 is a discharge lamp lighting circuit that operates at high frequency, and 24 is a fluorescent lamp.

The AC power supply 1 is controlled in its flow angle by a phase control dimmer 2 and is input to a full-wave rectifier 3 . The output of the full-wave rectifier 3 is passed through a diode 15 to smoothing capacitors 18 and 19 .
The signal is smoothed by a partial smoothing circuit composed of diodes 20 to 22 and input to a discharge lamp lighting circuit 23, and the output of the discharge lamp lighting circuit 23 causes the fluorescent lamp 24 to be lit at high frequency.

By the way, if the above-mentioned circuit is connected to the phase control dimmer 2, a capacitive load is connected to the 1-phase control dimmer 2, so the 1-phase control dimmer 2 malfunctions. To prevent malfunctions, it is best to connect a resistive load in parallel, but simply connecting it will increase power consumption in the resistor, so the output voltage waveform of the full-wave rectifier 3 V□ (
It is well known that the load resistor 4 can be turned on and off at the timing of the waveforms a) and 2, including the short overlap time T&.

The timing of the waveform shown in FIG. 2 is created by the control circuit 14 based on the waveform of vl divided by the resistors 8 and 9, and A signal for driving transistor 6 is outputted through transistor 7, diode 10, and resistor 11.

By the way, part of the power for this control circuit 14 is supplied via resistors 16 and 17 and stabilized by capacitor 12 and Zener diode 13, but if all the power is supplied from this system, resistors 16 and 17 Therefore, as in this embodiment, by directly flowing the current flowing through the load resistor 4 into the power supply of the control circuit 14, the current flowing through the load resistor 4 can be effectively used, and the power consumption of the resistor 16 increases. and 17 can be reduced.

〔Effect of the invention〕

According to the present invention, since excess power loss can be reduced, it is possible to realize a highly efficient and highly reliable discharge lamp lighting circuit that can be used in a phase 1iIIIF dimmer for light bulbs.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining the operation of one embodiment of the present invention. 4...Load resistance, 6 and 7...Transistor, 5
and 11...resistor, 10...diode, 8 and 9...resistor, 12...capacitor, 13...zener diode, 14...control circuit.

Claims (1)

[Claims] 1. A series circuit of a resistor and a switching element is connected between a rectifier that rectifies AC power and the output terminal of this rectifier, and a smoothing circuit is connected to the output terminal of the rectifier via a diode. A discharge lamp lighting circuit and a discharge lamp that operate at a high frequency are connected to the output, the switch element is opened and closed by the output from the control circuit, and part or all of the power supply of the control circuit is connected to the current flowing through the switch element. A discharge lamp lighting device characterized in that it is used.