Digital control of low-frequency, small-wattage, high-intensity discharge lamps

Abstract

A digital circuit for driving a low-frequency, small-wattage, high-intensity discharge lamp is proposed. By combining a digital potentiometer X9313 and a microcontroller STM32F103, the lamp can be turned on and off automatically according to the operating condition. The lamp power can be altered flexibly based on the needed luminance because it is designed to be a linear function of the resistance of the potentiometer X9313. The lighting system has an electrical efficiency of 88% and can save more than 20% of energy, compared with a traditional lamp. A remote desktop client on Android is developed for the purpose of wireless and convenient control. The proposed model will provide important information for designing high-performance, low-frequency, small-wattage, high-intensity discharge lamps.

A design methodology for acoustic resonance-free, high-frequency, dimmable electronic ballast for high-pressure sodium-vapour lamps

“…rectifier, power factor corrector (PFC) and inverter stage. 7 Rectifier converts the line frequency supply voltage into an unregulated dc voltage V d . The PFC is a boost converter working in discontinuous conduction mode (DCM).…”

“…Operation of the boost PFC must be in DCM to ensure minimized supply current harmonics and near-unity input power factor of the e-ballast. 7,18 Considering the boundary between discontinuous and continuous conduction modes, the sizes of the boost inductor, L boost (mH) and the boost capacitor, C boost (mF) are estimated from equations (18) and (19) 29,30 where Prated is the rated lamp power in Watts, fboost is the chosen switching frequency of the boost converter in kHz, ηi is the efficiency of the SPRI stage which typically lies in the range of 95%–100% and ΔVr is the maximum allowable ripple content of V o in volts (peak–peak).…”

“…Operation of the boost PFC must be in DCM to ensure minimized supply current harmonics and near-unity input power factor of the e-ballast. 7,18 Considering the boundary between discontinuous and continuous conduction modes, the sizes of the boost inductor, L boost (mH) and the boost capacitor, C boost (mF) are estimated from equations (18) and (19) 29,30…”

“…4,5 An effective solution to avoid the triggering of AR is the low-frequency square wave (LFSW) e-ballast technology. [6][7][8] An LFSW e-ballast mitigates the chance of AR occurrence in two waysfirst, it drives the HID lamp in the 50-400 Hz frequency region which is far below the ARprone window; second, the resulting lamp current and lamp voltage waveforms have identical rectangular shape which makes the instantaneous lamp power free from oscillatory components.…”

Assessment of the effect of a pulsed power supply on the HgTlI lamp

“…The electronic power supply (see Figure 1) is composed of the following components: [17][18][19][20] Two current sources: it is composed of a voltage source connected in series with an inductance and a resistance. The first source (I 0 ) gives the DC current to the 'H' Bridge.…”