مرکز منطقه ای اطلاع رساني علوم و فناوري - The Investigation of LED Driving Circuits Used at Pulsed High Currents

Abstract :

LED has been driven with the currents which have high amplitude and short pulse duration in pulsed high current operation mode. In this study, the investigation of the circuits which drive LED with pulsed high currents has been made. In this sense, the necessary timing integrated circuits which are used to drive LED such as astable multivibrators which generate pulses with short duty cycle and long space time and monostable multivibrators which generate short pulses when they are triggered from the input pin at a suitable time have been examined. A switching circuit is necessary to switch the LED current. The importance of some properties of switching active semiconductor device in the switching circuit such as current gain and saturation voltage has been specified. The ringing event which is important such as short pulses with high amplitudes has been explained. How the serial and parallel LED groups can be used to additional increasing the radiant power have been shown.