Energy-saving device for high-pressure discharge lamp

Abstract

The invention provides an energy-saving device for a high-pressure discharge lamp, and the energy-device performs energy saving of a high-pressure discharge lamp via a phase control of a power adjustment element, during change of energy-saving rate, poor lighting of the high-pressure discharge lamp will not be brought, and load of the power adjustment element caused by a startup current is reduced rightly after connection of a power source. The energy-saving device for a high-pressure discharge lamp comprises a TRIAC controlling power from an AC power to the high-pressure discharge lamp, a setting circuit setting an energy-saving rate, a zero-crossing circuit detecting a voltage wave form, and a storing circuit storing conducting timing sequence of TRIAC with respective to the voltage zero-crossing. Electrification of a relay is made rightly after power source conducting of a control circuit, and a phase control of TRIAC is started after stabilization of a startup current. During the phase control, the control circuit makes the conducting timing sequence change at a relatively steep gradient during small / big change of the energy-saving rate, preventing flickering and going-out of the high-pressure discharge lamp.

Description

technical field [0001] The invention relates to an electricity-saving device for reducing the power consumption of high-pressure discharge lamps such as mercury lamps and sodium lamps. Background technique [0002] Conventionally, there is known a device for reducing the power consumption of high-voltage discharge by controlling the turn-on timing of the power adjustment element. For example, the power saving device disclosed in Patent Document 1 is configured by providing a triac (TRIAC) as a power adjustment element between the AC power supply and the high pressure discharge lamp, and controlling the conduction of the TRIAC according to the power saving rate. timing, such as Figure 5 As shown, by stopping the arc discharge every half cycle of the voltage waveform, it is possible to save power corresponding to the waveform area of ​​the discharge stop period. [0003] Patent Document 1: JP Unexamined Publication No. 2009-277500 [0004] However, in existing power saving ...

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Problems solved by technology

[0004] However, in existing power saving devices, such as Image 6 When the power saving rate is changed as shown in (a) and the power target value is changed, as shown in (b), the timing of turning on the TRIAC (the delay time from the voltage zero crossing, refer to Figure 5 ) instantaneous change

Therefore, if the power saving rate is set high and the turn-on timing of the TRIAC is delayed with a large phase, there will be the following problems: the state of the vapor in the discharge tube will change drastically, and the arc discharge will become unstable, as shown in (c) As shown, the actual load power (power consumption) drops sharply, and the high-pressure discharge lamp flickers or goes out suddenly

However, if Figure 7 As shown, immediately after the power is turned on, a relatively large initial current of about 3 to 5 times the steady current flows for a long time, which increases the burden on the power adjustment element, and the life and reliability of the power saving device may not be stable. question

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