2018 Volume 102 Issue 2 Pages 65-70
LEDs are commonly used as a lighting apparatus for fluorescent and incandescent electric lamps. LED-lamp lighting circuits generally use a switching regulator system. Switching regulator systems can convert power efficiently and reduce the size of the circuit, but they generate high-frequency electromagnetic noise that can cause other instruments to malfunction. We examined series regulator systems as a potential solution to this problem because they have low electromagnetic noise. Specifically, we developed an LED-lamp lighting circuit that uses a series regulator system. This circuit is designed to change the number of operating LEDs in accordance with the power supply voltage. Using this system, we were able to achieve high power supply efficiency.
The power efficiency of the LED-lamp lighting circuit was 88.5 to 93.8% (average 90.8%) for power supply voltages from 90 to 110 V. In this circuit, the degree of variability in the total luminous flux was 21.7%.
