5-LED Chaser

475

07:09:55

          The illuminated LEDs in this circuit produce a chasing pattern when the PUSH BUTTON NO(at the bottom of the circuit before the capacitor) is tapped,this is similar to the running LEDs display in video shops. In fact the effect is called: "Running Hole." All transistors will try to come on at the same time when the power is restored due to the fluctuation in current caused by the PUSH BUTTON NO, but some will be faster due to their internal characteristics and some will get a different turn-on current due to the exact value of the 22uF capacitors

  *NOTE:
   Tap the PUSH BUTTON NO only ONCE

published 10 years ago

thuyenhb

10 years ago

Yaadeng

10 years ago

Good

Ifoegbu1

10 years ago

Thanks guys

Sine_eyed

10 years ago

@Ifoegbu1 - this circuit appears to be running smoothly but the waveforms show a funky fluctuation. Pick two of the transistors side by side, and highlight their base and collector nodes for the scope to see what I mean..

Ifoegbu1

10 years ago

@Sine_eyed - The fluctuation is responsible for the rhythm in the LEDs.That brings about different levels of brightness as the LEDs flash.

Sine_eyed

10 years ago

No. Did you highlight the nodes I suggested? When you do, observe the scope, and keep in mind that the lines shown should actually be very smooth..

Sine_eyed

10 years ago

I posted many examples of this topology a long time ago. Go to my page for descriptions/hints/clues/whatever.. X^)

Ifoegbu1

10 years ago

Ok I understand you now.As you'll notice the chasing effect changes pattern 1-5 times in less than a second.Therefore the irregularities in the waveform.

Sine_eyed

10 years ago

Nope, that's not it my friend. The problem is with the extra capacitor, and the fact that the right-most transistor's collector is tied directly to ground. I made my own adjustments to your circuit and observed much better performance. Let's see if you can too!..

Ifoegbu1

10 years ago

You're correct bro.Thanks a lot

Sine_eyed

10 years ago

;^)

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.