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I'm new to electronics and I can work only with transistors. I'm trying to create a circuit that performs action like this:
Let's say I have 10 LEDs. When I supply power first LED lights, 0.5 sec later second LED lights and 0.5 sec later third LED lights and so on. But all the LEDs keep lighting during others light.
I want to know if it's possible or not. If possible please give a link to such a tutorial.
Thanks all for help.

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It is possible using 10 bit Johnson counter with 2 Hz clock frequency, but it repeats the cycle after the last LED turns on (10th bit).


I added NAND gate(74LS00N) to the ckt for resetting all the states, when reaching the 10 bits are high,1 HZ signal can be generated by using 555 timer ckt

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  • \$\begingroup\$ repeating the cycle after the last led is so good :) thanks for your answer! i will try it. But sorry i can't vote your answer up :( \$\endgroup\$ – Eldar Zeynalov Sep 8 '14 at 7:18
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I would take a 555 square wave generator output from here 555 Oscillator Tutorial and drive shift register clock input from here The Shift Register. Shift registers input should high all the time.

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The answer I personally use in my circuits:

Use a sawtooth voltage (i.e. from simple BJT sawtooth generator) and a ADC with LED driver (LM3914 comes to mind, can drive 10 LEDs, no resistors needed) - you only require 1 IC and LEDs to do the visual part, but you can easily change the behaviour of the LEDs by changing the voltage ramping (sine, tri) and frequency.

Also, you'll get a fully functional ADC/VU meter/voltage meter in the meantime, free of charge.

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