Power transistor chopper circuit for discharge lamp operation

摘要

References(18) In this paper, is described the power transistor circuit for discharge lamp operation that chops the current flowing through the reactor at high frequency. The advantages of this circuit are as follows:(1) The high frequency operation results in smaller size and lighter weight of the ballast.(2) The lower voltage supply is available, because of the step-up function of the circuit.(3) The generation of high voltage, when a transistor is switched off, makes it easy to re-ignite the lamp.(4) The continuous control of the lamp power is possible by means of the variation of chopping duty cycle, therefore, the dimming is also easy.(5) This circuit can be used with dc or ac source in the same configuration.(6) In the same type of circult, it is able to operate the fluorescent lamp of various ratings and to apply to mercury, sodium lamps etc.Here, the experiment of fluorescent lamp operation is performed with dc power supply to verify the above-mentioned characteristics and the influences of the circuit’s constants are made clear by the numeical analysis using the simulated model of this circuit Furthermore, the experiment with ac power supply is examined and the various characteristics are clarified. In consequence, the availability of this circuit for the discharge lamp operation is confirmed.