This is the design diagram of the trafic baton with bulb flasher circuit. Similar with LED flasher version, the timer NE555 is wired as an astable multivibrator. The “on” period of flashing bulb is around 344 milliseconds and “off” period is around 329 milliseconds. The frequency is around 1.5 Hz. Bulb-driver transistors 2N3053/ BD139 and 2N2905/BD140 are used to light up the lamp. Two diodes are used in series with the base of 2N2905 to increase the forward voltage in order Bto ensure that when BD139 is conducting, BD140 is cut-off. Slide switch S2 is used to change the colour status of the flashing bulb.