Running LED light. Do It Yourself.

Running LED light. Do It Yourself.One version of lighting effects popular today is a construction with light-emitting diodes named running lights.As any compact LED device that operates from an independent power supply, it operates with minimal power consumption, creates striking effect by alternately flashing LED.Design is a conventional switch, which delivers voltage in turns to each of LEDs. Device contains only 2 chips, 10 transistors, together constituting master oscillator, control and indication.A lot can be said about excellence and value of components included in the circuit, but we will briefly recall about them and about the device.Master oscillator that generates control impulses is commonly known chip NE555. Operating frequency is determined by chain R1, C1.Further, impulses from generator output are fed to control unit, which is based on chip CD4017 also known as 561IE8 or decimal counter.First, voltage of logical zero is present at circuit output, i.e. it is not enough to open transistors.Only when first impulse reaches input of the counter, voltage of logical one is formed, which means the output will be fed with voltage of higher level.From output voltage is fed to transistor base and opens it. As a result through an open transition of "collector-emitter" of transistor the anode LED becomes connected to positive of power supply, causing it to glow.Second impulse generates a logical one on the next counter output, at the same time low voltage will appear on previous transistor and close it, LED will also turn off. Then everything happens in the same sequence continuously on each of 10 outputs of the chip.In addition it should be mentioned that the scheme uses tested KT315 transistors and also popular bright LEDs by company "BRIGHT LED". Composition of LEDs is mounted on compact disc; device itself is positioned on CD rear side on a small segment of printed circuit board. All components are placed in a neat package from compact discs. There are four cases for batteries with the power switch on its lower side.It remains to insert the batteries and turn on the device...