i will do it but i need a little time

Originally Posted by blueroomelectronics

Sounds like you've got lots of time.

Originally Posted by ssrssd

ok
time got over yesterday im just here for learning and other things
it was not really an assignment i just answered unexpected question that was out of my knowledge and their teachings.

i think i found out and try to answer today

Originally Posted by audioguru

It is time for you to do some simple research and answer your own questions.
1) When the dot is lighted then is the output of IC1D high or low?
2) When IC3 is reset are its outputs displaying anything?
3) When IC3 begins to display "1" is its pin 1 going high or going low?

hi friend .apology for my long delay
1:low
2:0
3:going to high since it work with low to high transition

i had busy days and mind.i did not analyze Q2 function.i just answered to questions and some guesses ...
like when out put IC1D is low Q2 is in common base condition and Vbe is provided & dot light up
so dot light up every 64 pulses after 32 pulses the drive IC3
...

nobody check my answer?

Originally Posted by audioguru

Q1 and Q2 are not common-base. They are common-emitter.

You can analyse the circuit until you are as tired of it as I am, or you can build it to see how it works.

I built it
i will analyze it completely